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Path: senator-bedfellow.mit.edu!bloom-beacon.mit.edu!news2.telebyte.nl!news.completel.fr!ircam.fr!freenix!nntp.cs.ubc.ca!newsfeeds.ihug.co.nz!ihug.co.nz!news.comnet.co.nz!not-for-mail From: Bruce Hamilton <B.Hamilton@irl.cri.nz> Newsgroups: sci.chem,sci.answers,news.answers Subject: Sci.chem FAQ - Part 3 of 7 Followup-To: sci.chem Date: Thu, 15 Jan 2004 22:10:05 +1300 Organization: Industrial Research Limited Lines: 1021 Approved: news-answers-request@mit.edu Expires: 15 Feb 2004 00:00:01 GMT Message-ID: <l5mc00tkmrnmar0lmu6tdo2asoggot7rcm@4ax.com> Reply-To: B.Hamilton@irl.cri.nz NNTP-Posting-Host: ippool31-189-irl.remote.irl.cri.nz Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: news.comnet.co.nz 1074157805 19200 131.203.243.189 (15 Jan 2004 09:10:05 GMT) X-Complaints-To: usenet@news.comnet.co.nz NNTP-Posting-Date: 15 Jan 2004 09:10:05 GMT X-Newsreader: Forte Free Agent 1.93/32.576 English (American) Xref: senator-bedfellow.mit.edu sci.chem:239411 sci.answers:15722 news.answers:264287 Archive-name: sci/chem-faq/part3 Posting-Frequency: monthly Last-modified: 22 October 1999 Version: 1.17 Subject: 11. Traditional Specialist Chemical Information Sources 11.1 Where can I find spectral libraries/databases? The most likely place is near to an instrument. These are not usually in general technical libraries, but are kept near the instruments. A polite request to the person in charge of the instrument should identify who to contact for permission to use the library or database. There is some spectral information in reference texts, such as the Rubber Handbook and the Merck Index, but most compilations are now so large that they cover several volumes. There are several compilations that are available commercially, either in hard copy (HC) or CD-ROM (CD) - which is usually more expensive because of the included searching software. Chemical manufacturers, such as Aldrich, may also sell spectral libraries, eg IR $495(HC) [1], FT-IR $875(HC) or $1578(CD) [2], 60MHz H1 NMR $495(HC) [3], and 300MHz H1 + 75MHz C13 NMR $1072(HC) [4], as well as offering compilations from government agencies, eg the NIST/EPA/NIH Mass Spectral database $1320(CD)[5]. The databases are also sold by several instrument manufacturers. One commercial supplier of spectral information ( Fiveash Data Management, Inc. ) may be accessible via the Internet [6]. 11.2 Where can I find polymer chemistry information? The first stop should be the multi-volume Encyclopedia of Polymer Science and Engineering [7], which should be in most technical libraries. Specific polymers are covered in much less detail in Kirk Othmer. There are several journals devoted to polymer science and chemistry, including the Journal of Polymer Science. 11.3 Where can I find analytical chemistry information? There is a sci.chem.analytical group where specific questions can be posted after you have attempted to find the information in the following sources. For qualitative information, the spot test books by Fiegl [8,9] and "Semi-micro Vogel"[10], are good starting points. For introductory quantitative analysis, "Quantitative Inorganic" [11],"Practical Organic Chemistry"[12] by Vogel are good introductions to non-instrumental techniques. The multi-volume "Treatise on Analytical Chemistry" by Kolthoff and Elving [13] comprehensively discusses most techniques, and several volumes of the ACS Series "Techniques in Chemistry" [14] also cover analytical procedures. " Instrumental Methods of Analysis" by Willard, Merritt, Dean and Settle [15], and "Analytical Instrumentation Handbook" by Ewing [16] provide a good introduction to chemical instrumentation. Most educational institutions will have equivalent texts if they are not using the above. For specific analyses it is often desirable to use standard procedures, especially if your laboratory is seeking ISO 9001 accreditation, or if the results are likely to be disputed. Some well known compilations of standard methods include:- Laboratory Reagents - usually specified by manufacturers or chemical societies BDH 'Analar' Standards for Laboratory Chemicals [17] ACS Reagent Chemicals [18] Materials, Industrial Chemicals, and Finished Products. - usually the monographs in the following volumes also specify assay and impurity limits, as well as detailing the analytical procedure. ASTM - Issued annually, cover physical and chemical testing of a wide range of industrial products. Often require specialised test equipment. ISO - International standards, usually derived from US(ASTM), UK(BSI) or FRG(DIN) standards. Similar to above. Pharmaceuticals - usually the pharmacopoeia have monographs and methods, but some methods are also specified in National Formulary or Pharmaceutical Codex volumes, which may be separate from the pharmacopoeia. - common pharmacopoeia are USP, BP, and EP - with Martindale [19] often used to ascertain where and when a specific monograph appeared. Food - often the procedures specified in Government legislation. - The Official Methods of the AOAC [20] covers many routine US methods. Environmental Pollution - the procedures are usually specified in the relevant legislation, and frequently US EPA procedures are used. Several common EPA procedures are now available on computer disk [21,22]. Petroleum - usually covered by ASTM, ISO or DIN, but there are some unique IP ( Institute of Petroleum - UK ) procedures that are also used. - "Chromatography in Petroleum Analysis"[23], summarises popular techniques. Gases - instrument manufacturers have fairly detailed procedures for process gases. - "The Analysis of Gases by Chromatography"[24], provides useful examples. Water and Wastewater - the APHA/WWA/WPCF standard methods are most often used [25] - many tests are also covered by ASTM, ISO, and DIN procedures - alternative techniques are described in "Water Analysis" [26] - organics in water are covered by Crompton [27] - most aspects of water chemistry are detailed in Franks [28] Sample Preparation - consumable and instrument manufacturers often provide detailed manuals and guides free. - "Methods of Decomposition in Inorganic Analysis" [29] covers a wide range of preparations for spectroscopy. - The "Handbook of Analytical Derivatization Reactions" [30] and the " Handbook of Derivatives for Chromatography" [31] cover many of the techniques for gas and liquid chromatography. Obviously there are several journals devoted to various aspects of analytical chemistry. The April issue of Analytical Chemistry publishes a review of papers published during the previous two years. The review alternates between Fundamental and Application Reviews and is a quick means of catching current trends if you are unable to locate an expert. 11.4 Where can I find environmental chemistry information? There are several standard texts used by environmental chemistry classes that provide good general introductions, eg "Environmental Chemistry" [32] "Fundamentals of Environmental Chemistry [33], and "Environmental Organic Chemistry" [34]. They should be available in most technical libraries. The monthly journal "Environmental Science and Technology" covers most aspects of environment chemistry. "Chemosphere" concentrates on toxins such as PCBs and Dioxin, and " Science of the Total Environment also covers many aspects. Government agencies such as the EPA also publish large amounts of information, and many environmental groups also provide significant amounts of technical information. There are a range of specialist texts that cover specific pollutants, eg "Metals and their Compounds in the Environment: Occurrence, Analysis and Biological Relevance" [35]. The sci.environment Usenet group may well be a better place to request environmental chemistry information than sci.chem, but please remember to move discussions to talk.environment. 11.5 Where can I find physical chemistry information? General introductory information will be available in any technical library where chemistry is taught, and one of the more popular modern texts is "Physical Chemistry" by P.W.Atkins [36], and a classical text is "Textbook of Physical Chemistry" by S.Glasstone [37]. The multi-volume ACS series "Physical Methods of Chemistry"[38] also covers many physical chemistry techniques. There are also the Journal of Chemical Physics and the Journal of Physical Chemistry. Frankly, I would not have a clue where else to go. 11.6 Where can I find inorganic chemistry information? General introductory information will be available in any technical library where chemistry is taught. One popular text is "Inorganic Chemistry" by D.F.Shriver, P.W.Atkins, and C.H.Langford [39], which also has the answers available as a separate book. "Inorganic Vogel"[40], also discusses the theory of the analyses. There are three major multi-volume inorganic encyclopedias. Mellor is frequently found in public libraries, and provides a broad cover of the field, however the more comprehensive is Gmelin [41], which will be available in most institution libraries. The more recent developments and mechanisms are covered in the multi-volume "Encyclopedia of Inorganic Chemistry" [42], which may be difficult to find due to its $2500 price. "Advanced Inorganic Chemistry" [43] by F.A.Cotton and G.Wilkinson provides a good base to start. There are several journals that cover aspects of inorganic chemistry. 11.7 Where can I find organic chemistry information? General introductory information will be available in any technical library where chemistry is taught. One popular modern text is " Organic Chemistry " by T.W.G.Solomons [44], but my favourite is "Organic Chemistry"[45] by Fieser and Fieser - a much more practical discussion of organic molecules. Once you are familiar with organic chemistry mechanisms then "Advanced Organic Chemistry" by Carey and Sandberg [46] is a good overview. There are several compilations of organic synthesis techniques to assist researchers. The multi-volume sets "Organic Reactions" [47], and "Reagents for Organic Synthesis" [48], are examples of sets that will be available from institution libraries. There are some good theoretical texts available, eg "The Logic of Chemical Synthesis" [49]. For specific preparation and properties of individual compounds, then Heilbron [50] and Beilstein [51], are the initial resources of choice. There are several journals devoted to organic chemistry in general, including Journal of Organic Chemistry, Tetrahedron, etc.. Specific branches of organic chemistry, such as Carbohydrates, Lipids, or Proteins have their own journals, as do applications such as pharmaceuticals and pesticides. 11.8 Where can I find industrial chemistry information? The best single volume remains Shreve's "Chemical Process Industries" [52]. There are three major multi-volume encyclopedias, Kirk Othmer, Ullmann, and McKetta, that cover many aspects of industrial chemistry and at least one is usually available in a public library. There are also several journals that provide good overviews of industrial chemistry, the easiest to read being C&EN, and Chemtech. Research is usually published in Industrial and Engineering Chemistry ( which is an excellent source for historical research ), and specialist chemical engineering journals. 11.9 Where can I find pharmaceutical chemistry information? Pharmaceutical research often is initially reported in patent literature, consequently patent searching is a good place to start. The Merck Index is focused on pharmaceuticals, and also provides excellent leads to the research literature. There are several pharmaceutical chemistry books, such as Goodman and Gilman [53], and "Essentials of Medicinal Chemistry" [54], that provide overviews of the field. The Journal of Pharmaceutical Chemistry is a good source for research articles. Details of chemicals appearing in formulated products can be found in the "Handbook of Pharmaceutical Excipients" [55]. ------------------------------ Subject: 12. Nomenclature 12.1 What are CAS Registry Numbers? When chemicals are first encountered by the Chemical Abstracts Service, they are assigned a unique number when they are registered. These numbers are not related to any structure or property of the molecule, they are arbitrarily assigned. It should be remembered that occasionally a compound may be accidentally assigned two or more numbers - especially industrial products that have not been completely characterised. When this is discovered, one of the numbers is no longer used. The numbers usually take the form of [xx-yy-z to xxxxxx-yy-z] and square brackets are often used in monographs to identify the CAS Registry Number [RN]. The easiest way to locate the CAS RN for commercially-available chemicals is to look in suppliers catalogues ( eg Aldrich) or compilations ( eg Merck or Hawley ), almost all chemical texts now list the RN, and several ( eg Merck Index and Aldrich ) have a cross-reference Index. The RN is extremely useful for on-line searching of Chemical Abstracts and several other popular chemistry-related databases, but is not particularly useful for the hardcopy version, except to confirm compound identity. 12.2 What are the correct names of recently-discovered elements? The Transfermium Working Group was established in 1986 by the International Union of Pure and Applied Chemistry (IUPAC) and the International Union of Pure and Applied Physics (IUPAP). The working group published several reports, and then recommended that elements should not be named after living persons [1]. This greatly upset the USA - who wanted to name an element after G. Seaborg. After protracted negotiations, a compromise selection of names was finally approved by the IUPAC Commission on Nomenclature in Inorganic Chemistry, the IUPAC Inorganic Division, the IUPAC Bureau, and the selection was eventually ratified by the IUPAC Council meeting in Geneva during August 1997 [2]. 101 Mendelevium Md D. Mendeleev (Russia) 102 Nobelium No Nobel Institute (Sweden) 103 Lawrencium Lr E. Lawrence (USA) 104 Rutherfordium Rf E. Rutherford (NZ) 105 Dubnium Db Dubna = Russian Research Centre 106 Seaborgium Sg G. Seaborg (USA) 107 Bohrium Bh N. Bohr (Denmark) 108 Hassium Hs Latin name for German state of Hesse 109 Meitnerium Mt L. Meitner (Austria) Note that Hesse is where the German heavy-element laboratory is based. The Gesellschaft fur Schwerionenforschung (GSI) was responsible for the first man-made creation of elements 107-110. The compromise will now move attention to the naming the recently-discovered elements 110-112. 12.3 What is the nomenclature system for CFCs/HCFCs/HFCs? The CFC naming system was developed by T.Midgley,Jr. and A.L.Henne in 1929, and further refined by J.D.Park. Originally, organic molecules that contained Chlorine and Fluorine were all referred to as CFCs. Today, the group is subdivided into CFCs, HCFCs, and HFCs. The naming system consists of:- CFC-01234a where 0 = number of double bonds ( omitted if zero ) 1 = Carbon atoms - 1 ( omitted if 0 ) 2 = Hydrogen atoms + 1 3 = Fluorine atoms 4 = Chlorine atoms replaced by Bromine ("B" prefix added ) a = letter added to identify isomers, the "normal" isomer in any number has the smallest mass difference on each carbon, and a, b, or c are added as the masses diverge from normal. If the compound is cyclic, then the number is prefixed with "C". There are several other refrigerants, some of which are hydrocarbons, hydrocarbon blends, or CFC blends. Full details of the nomenclature system are specified in ANSI/ASHRAE Standard 34-1992 with additional annual supplements. Chemical names are frequently used in place of the numbers for common materials - such as trichloroethylene and chloroform. The specified ANSI/ASHRAE prefixes were FC ( FluoroCarbon ), or R ( Refrigerant ), but today most are prefixed by more specific classifications - such as CFC, HCFC, and HFC. CFC-11 CCl3F trichlorofluoromethane [75-69-4] CFC-12 CCl2F2 dichlorodifluoromethane [75-71-8] CFC-113 CCl2F-CClF2 1,1,2-trichlorotrifluoroethane [76-13-1] HCFC-22 CHClF2 chlorodifluoromethane [75-45-6] HCFC-123 CHCl2-CF3 2,2-dichloro-1,1,1-trifluoroethane [306-83-2] HCFC-123a CHClF-CClF2 1,2-dichloro-1,1,2-trifluoroethane [354-23-4] HFC-23 CHF3 trifluoromethane [75-46-7] HFC-134 CHF2-CHF2 1,1,2,2-tetrafluoroethane [359-35-3] HFC-134a CH2F-CF3 1,2,2,2-tetrafluoroethane [811-97-2] R-20 CHCl3 chloroform [67-66-3] R-22B1 CHBrF2 bromodifluoromethane [1511-62-2] R-1120 CHCl=CCl2 trichloroethylene [79-01-6] R-1150 CH2=CH2 ethylene [74-85-1] R-C316 C4Cl2F6 1,2-dichlorohexafluorocyclobutane Another technique for naming CFCs uses the addition of 90 to the CFC number to produce a "def" number which corresponds to the CHF composition. If (e + f) < (2d + 2), then additional atoms are required for saturation. This technique has been described in detail in the Journal of Chemical Education [3]. ASHRAE +90 Empirical Composition Formula C H F (+Cl) CFC-11 101 1 - 1 3 CCl3F CFC-12 102 1 - 2 2 CCl2F2 HCFC-22 112 1 1 2 1 CHClF2 HCFC-123 213 2 1 3 2 CHCl2-CF3 HFC-134a 224 2 2 4 - CH2F-CF3 Halons are numbered according to a totally different system developed by the US Army Corps of Engineers, and the prefix term is always "Halon". Hydrogen is not numbered, and terminal zeros are not expressed. Halon-0123 where 0 = number of carbon atoms 1 = number of fluorine atoms 2 = number of chlorine atoms 3 = number of bromine atoms Halon-1211 CBrClF2 bromochlorodifluoromethane [353-59-3] Halon-1301 CBrF3 bromotrifluoromethane [75-63-8] Halon-2402 CBrF2-CBrF2 1,2-dibromo-1,1,2,2-tetrafluoroethane [124-73-2] 12.4 How can I get the IUPAC chemical name from traditional names? It depends. Usually the quickest way is to look the name up in a chemical supplier's catalog, MSDS, or a standard text like Merck or Hawley. You can also often find the correct name if you refer to an old chemistry text that lists both the traditional and IUPAC naming conventions. Some traditional or common names also refer to mixtures of chemicals, eg aqua regia, piranha solution. One reason why traditional names have been replaced is because the same name could be used for different compounds. An example is the use of caprylic to describe 1-Octanol and 2-Octanol, and attempts to qualify the name with "primary" and "secondary" were less than successful. Octyl alcohol has been used to describe both 1-octanol and 2-ethylhexanol, thus explaining why the well known dioctyl phthalate (DOP) is actually bis(2-ethylhexyl) phthalate. The following examples highlight the diversity of names often encountered. Carbon Alkane Alcohol Aldehyde Acid 1 methane methanol form- formic carbinol 2 ethane ethyl acet- acetic methyl carbinol 3 n-propane n-propyl propion- propionic ethyl carbinol 4 n-butane n-butyl n-butyr- n-butyric propyl carbinol 5 n-pentane n-amyl n-valer- n-valeric butyl carbinol 6 n-hexane hexyl capro- caproic amyl carbinol caproic 7 n-heptane enanthyl enanth- enanthic enanthic hexyl carbinol 8a n-octane capryl capryl- caprylic primary caprylic caprylic heptyl carbinol 1-octanol 8b capryl secondary caprylic methyl hexyl carbinol 2-octanol 9 n-nonane pelargonic pelargonic pelargonic octyl carbinol 10 n-decane capric capr- capric nonyl carbinol capric 12 n-dodecane lauryl laur- lauric lauric lauryl 14 n-tetradecane myristyl myrist- myristic 16 n-hexadecane cetyl palmit- palmitic cetane 18 n-octadecane stearyl stearic 20 n-eicosane arachidyl arachidic Primary - alcohol R1CH2OH - amine R1NH2 eg normal straight chain normal octane n-octane normal butanol 1-butanol iso branched chain iso-butane 2-methylpropane iso-butanol 2-methyl-1-propanol iso-octane 2,2,4-trimethylpentane Secondary - alcohol R1R2CHOH - amine R1R2NH eg sec-butanol 2-butanol iso-propanol 2-propanol Tertiary - alcohol R1R2R3COH - amine R1R2R3N eg tert-butanol 2-methyl-2-propanol - substitution onto the benzene ring 1,2 = ortho ortho-xylene 1,3 = meta meta-xylene 1,4 = para para-xylene However other names get more tricky, especially historical names, where several names may be used for the same chemical and, even worse, different chemicals can be described by the same name. Examples include:- - calcium carbonate = limestone, chalk, calcite. - calcium hydroxide = slaked lime, hydrated lime, caustic lime. - calcium oxide = calx, lime, quicklime, unslaked lime, burnt lime. - hydrochloric acid = muriatic acid, spirits of salts. - nitric acid = aqua fortis. - potassium carbonate = potash, artificial alkali, vegetable alkali. - potassium hydroxide = caustic potash, lye. - sodium carbonate - any form = soda, natural alkali, mineral alkali. - anhydrous = soda ash. - dodecahydrate = sal soda, washing soda. - monohydrate = soda crystals. - sodium chloride = rock salt. - sodium hydroxide = caustic soda, lye, soda lye. - sulfuric acid = oil of vitriol Some old chemical terms are seldom encountered these days, but have very specific meanings, eg " flowers " described any product of sublimation, hence "flowers of sulfur". " specific " in front of any quantity means " divided by mass ", hence "specific gravity". " ether " described a volatile liquid, not only compounds with the Cx-O--Cy structure, and also often known today as "spirit". " aromatic " described a liquid that had an aroma, not only those derived from benzene, or which benzene ring structure. " oil " described a liquid that was not miscible with water, thus it described different products in different chemical industries :- - Essential oils = volatile and odoriferous liquid plant extracts. Essential oils can be obtained by extraction or distillation ( steam ), often contain terpenes ( based on the isoprene structure ), are usually smelly ( aromatic ), and are used for perfumes, flavours and aromas, eg lemon oil and pine oil. - Triglyceride oils = fats and oils based on the glycerol molecule that can be obtained from plant and animal material, frequently by melting or cold pressing. They are a significant, and important, component in our diet, eg soya oil, lard, fish oils, and anhydrous milk fat. - Petroleum oil = a mixture of a large number of hydrocarbons that are usually derived from 0.1 to 3 billion-year-old organic matter. Crude oil can contain hundreds of hydrocarbons with one to sixty carbon atoms, and the hydrocarbons are usually grouped and reported by type, eg alkane ( paraffin ), alkene ( olefin ), or arene ( aromatic ). Almost all old industries had easy-to-remember names for chemicals they commonly encountered, but today many of those names can cause confusion if used outside the industry. Some common examples, just from the petroleum industry alone are:- - " ether " is a volatile hydrocarbon fraction that does not contain the Cx-O-Cy structure, eg petroleum ether ( aka petroleum spirit ). - " naphthene " is a cyclic paraffin, does not contain naphthalene, and is not a major component of naphtha ( refer Section 27.5 ). - Benzene, toluene and xylene are often called benzol, toluol, and xylol, even though they do not contain an -OH group. - Benzine ( ligroin ) was a saturated hydrocarbon fraction that boiled between 20C and 135C. Gasoline/petrol fractions are still called benzine by some older people. - Diesel fuel is often called "gas oil", which is a historical term for hydrocarbon distillate fractions. Atmospheric gas oil has a boiling range between 220C - 450C, and vacuum gas oil boils from 350C to 550C. 12.5 What does "omega-3 fatty acids" mean? Chemists recognise that they should always number carbon chains from the end with the functional group, so the location of double bonds in unsaturated fatty acids are numbered from the carboxylic acid end, and are usually designated by "delta" in their abbreviated names. Biochemists are more interested in the actual role that chemicals play, consequently they will consider the position from the end that is important. In the case of natural fatty acids the double bonds are usually cis configured, and it is the distance of the first double bond from the terminal end of the carbon chain that is important. They use "omega" to signify that the double bond is cis, and they are counting from the other end. The great advantage is that chain length can be ignored, and compounds that are subjected to the same biochemical processes are grouped together. In 1967, the IUPAC/IUB commission responsible for lipid nomenclature recommended that for unsaturated fatty acids with cis double bonds, that the "omega" symbol be replaced with "n-x", where n = the length of the carbon chain, and x is the distance from the terminal end. Some examples:- Common Chemical Chemical Biochemical Name Name d = delta o = omega Oleic cis-9-octadecenoic c-C18:1d9 C18:1o9 Elaidic trans-9-octadecenoic t-C18:1d9 - Ricinoleic D-(+)-12-hydroxy-octadec-cis-9-enoic c-C18:1d9-12OH - Linoleic cis-9,12-octadecadienoic c-C18:2d9 C18:2o6 alpha Linolenic cis-9,12,15-octadecatrienoic c-C18:3d9 C18:3o3 gamma Linolenic cis-6,9,12-octadecatrienoic c-C18:3d6 C18:3o6 Arachidonic cis-5,8,11,14-eicosatetraenoic c-C20:4d5 C20:4o6 EPA cis-5,8,11,14,17-eicosapentaenoic c-C20:5d5 C20:5o3 Erucic cis-13-docosenoic c-C22:1d13 C22:1o9 DHA cis-4,7,10,13,16,19-docosahexaenoic c-C22:6d4 C22:6o3 EPA and DHA are widely known as the omega-3 fatty acids present in high concentrations in marine lipids, and are considered beneficial in diet, although research is not complete [4,5]. 12.6 What is Conjugated Linoleic Acid? Conjugated linoleic acid describes the group of positional and geometric isomers of linoleic acid ( cis-9,12-octadecadienoic acid ) that have a conjugated double bond system starting at carbon 9, 10, or 11. They can be either cis or trans, or various combinations of them. The more abundant isomers in food are believed to be the cis-9, trans-11, and the trans-10, cis-12 isomers. It's very difficult to separate the cis-9, trans-11 and trans-9, cis-11 isomers, however the cis-9, trans-11 form is usually considered the important and usually dominant isomer. They are typically produced by bacteria in the rumen of ruminants because the hydrolysis of fats in the rumen produces more unesterified linoleic acid than is available to bacteria in other digestive systems. Plants also contain conjugated linoleic acid, but there is much less of the cis-9, trans-11 isomer, which is believed to be the biologically active isomer. Foods that contain CLA are lamb, beef, turkey and dairy fat products, ranging from 2.5 - 11 mg/g of fat - of which 75% or more is the cis-9, trans-11 ( or trans-9, cis-11 ) isomer. CLA is of interest because it has displayed antimutagenic activity in animals and human cell tests [6,7]. 12.7 What are "heavy" metals? There appears to be no standard definition, however the general consensus appears to be all metals with a density greater than 4 or 5 [8,9,10]. If you also consider the conventional analytical chemistry definition of "heavy metals" ( precipitation of sulfides from acidic solutions ), you obtain quite a diverse mixture of possible candidates. Moving the density limit from 4 to 5 really only just impacts on Ti, Y and Se. Some other texts use more complex definitions that may also include accepted "light" metals with densities less than 4, eg Hawley uses "A metal of atomic weight greater than sodium (22.9) that forms soaps on reaction with fatty acids. e.g., aluminum, lead, cobalt". The term " heavy-element " is commonly used to describe the transfermium elements, - elements with an atomic number greater than 100. 12.8 What is the difference between Molarity and Normality?. A Molar solution contains one gram molecular weight ( aka mole ) of the reagent in one litre of solution, and is represented by " M ". In modern usage, "molar" is intended to only mean " divided by amount of substance", and is not supposed to be used to describe 1M solutions. There are already exceptions to the rule ( molar conductivity, molar extinction coefficient ), so I would only worry about correct usage in exams, as in the real world most chemists use Molar to describe 1M solutions. A Molal solution is one gram molecular weight of the reagent in 1 kilogram of solvent, and is usually represented by "m". This concentration unit is relatively uncommon in the real world, so it's worth checking that the "m" is not a "M" typo. A Normal solution contains one gram equivalent weight ( aka equivalent ) of the reagent in one litre of solution, and is represented by " N ". The equivalent weight of a reagent may vary according to the reaction, but if considering just acid and base moles and equivalents, then:- 1M H2SO4 + 2M NaOH -> 2H2O + Na2SO4 1N H2SO4 + 1N NaOH -> H20 + 0.5Na2SO4 1N HCl + 1N NaOH -> H2O + NaCl So you can see that the equivalent weight of an acid is that which contains 1.0078 grams of replaceable hydrogen which, in the case of sulfuric acid, would be half the mole weight, but, in the case of hydrochloric acid, would be the mole weight. The equivalent weight of a base is that which contains one replaceable hydroxyl group ( ie 17.008g of ionisable hydroxyl ). Thus the equivalent weight of sodium hydroxide ( NaOH ) and potassium hydroxide ( KOH ) would be the mole weight, but for calcium hydroxide ( Ca(OH)2 ) it would be half the mole weight. The equivalent weight of an oxidising or reducing agent is that weight of the reagent that reacts with or contains 1.008 grams of available hydrogen or 8.000 grams of available oxygen. "Available" means being able to be utilised in oxidation or reduction reactions. The equivalent weight of an oxidising agent is determined by the change in oxidation number which the reduced element experiences, eg the reduction of potassium permanganate in dilute H2SO4 gives;- K Mn O4 --> Mn S O4 (Oxidation Number) +1 +7 -8 +2 +6 -8 This results in a change of the manganese from +7 to +2, so the equivalent weight is 1/5 of a mole. However, in neutral solution the change would only be 3 because the product is MnO2, giving an equivalent weight of 1/3 of a mole. If reacted in strongly alkaline solution the product is MnO4--, giving an equivalent weight of one mole. The equivalent weight of a reducing agent is determined by the change in oxidation number that the oxidised element undergoes. For the conversion of ferrous sulfate into ferric sulfate;- 2 (Fe SO4) --> Fe2 (SO4)3 (Oxidation Number) 2x(+2 -2 ) (+3)x2 (-2)x3 The change in oxidation number per atom of iron is 1, so the equivalent weight of ferrous sulfate is 1 mole. There are wide range of rules about the determination of the oxidation number, but if you have been taught to use molarity, I would not bother too much about normality, as it is mainly used these days by analytical chemists - because it is convenient for many common titrations. Analysts assume that 1 ml of 1N reagent will react with 1 ml of 1N reagent. However, there has been a recent Journal of Chemical Education article that claims using normality and equivalent weight does help students understand chemistry, but those concepts are unlikely to become widespread again [11]. 12.9 Where can I find the composition of common named reagents?. Often the best place to start are MSDS sheets or catalogues from commercial suppliers. Some textbooks include a list of named reagents and their composition that are mentioned in the text. The very common reagents are usually also detailed in Hawley or the Merck Index. One chemistry field that has a lot of named reagents is analytical chemistry, especially in Thin Layer Chromatography, where many of the spray detection reagents have common names. Merck produces a handy guide describing the composition and production of common TLC spray reagents [12]. Some common reagents include:- - aqua regia = 1 part nitric acid and 3 or 4 parts hydrochloric acid. - piranha solution = highly dangerous ( explodes on contact with traces of organics ), warm (65C), 70:30 mixture of 100% sulfuric acid and 30% hydrogen peroxide. It is used, with comprehensive safety precautions, in the semiconductor industry, and also in some laboratories to clean glassware [13,14,15]. Many chemical laboratories prohibit it, and there are much safer, equally effective, alternatives available - refer Section 16.7. ------------------------------ Subject: 13. Illicit and Government Controlled Substances Contributed by : Yogi Shan ## <yshan@nortel.ca> [ mutilated by Bruce Hamilton, who agrees with what Yogi has written, but has tried to make the FAQ format consistent, and added his opinion. ] 13.1 What newsgroups/mailing lists discuss illegal drugs? Current Usenet Newsgroups: alt.drugs.* ( 18 different groups including a.d.c ) alt.drugs.chemistry alt.psychoactives alt.hemp talk.politics.drugs alt.rave alt.consciousness # rec.drugs.announce # rec.drugs.cannabis rec.drugs.chemistry # rec.drugs.misc # rec.drugs.psychedelic # rec.drugs.smart Mailing lists: mdma/ecstasy/"E": To subscribe, send mail to listpimp@underground.net with the message: SUBSCRIBE mdma <your name> psychedelics: Leri-L (Leri-L Metaprogramming Mail Service) Contact: leri-request@pyramid.com TTIL is a moderated mailing list whose purpose is the respectful discussion of Psychedelic Religion. To subscribe send email to: listproc@phantom.com and put in the body of the message: subscribe ttil <your email address> There are several useful FAQs available in alt.drugs - start there with Yogi's Clandestine Chemistry FAQ. Comprehensive overviews of illicit drug information available on the Internet are maintained at several sites, eg http://hyperreal.com/drugs/ 13.2 Where can I obtain a list of illegal drugs? From the "Law" Section of the "alt.drugs Clandestine Chemistry Primer/FAQ" by Yogi Shan (yshan@nortel.ca), reproduced by permission: The drug statutes (possession, conspiracy, and sale), including Schedules I to V of the Controlled Substances Act (listing all banned and federally regulated drugs and precursors) are in Title 21 [of the United States Code] Sections 800-900 (21 USC 800-900). The US Code is available on the Internet: http://www.pls.com:8001/his/usc.html http://thorplus.lib.purdue.edu/gpo/ or as gzip compressed files (by Title): ftp://etext.archive.umich.edu/pub/Politics/Conspiracy/AJTeel/USC/ A current list of proscribed drugs may be obtained by writing to: Drug Enforcement Administration Attn: Drug Control Section 1405 "I" Street, N.W. Washington, D.C. 20537 13.3 What is the chemical structure of common illegal drugs? See the Merck Index for the chemical structure of your favourite poison. Heilbron ( aka "Dictionary of Organic Compounds ), a multi-volume set, is also excellent, and more up to date, though less commonly available. Serious structure chasers should also check Beilstein, which often provides far more detail of properties and structure than Merck or Heilbron. 13.4 How do I obtain chemical information on illegal drugs? Merck, Heilbron and Beilstein all provide information on drugs that have a significant presence in the market. Lesser-known homebake and analogues are usually not covered, and a search of Chemical Abstracts may not even provide information. Because of the various techniques used to "refine" and "cut" the active ingredients, most illegal drugs are seldom sufficiently pure to match published data. The drugs are marketed on their pharmacological and psychological activity, rather than chemical purity - similar to vitamin units of activity :-). I suggest you start by reading the various alt.drugs FAQs - they all list hardcopy references, and if they do not identify an information source, try posting to alt.drugs or rec.drugs. 13.5 Where are the synthesis instructions for illegal drugs? By asking the question in sci.chem, you already have signalled your level of knowledge of illicit chemistry discussions on Usenet. You should be in alt.drugs.* hierarchy and perhaps other groups in section 13.1 :-). For the short answer, refer to Merck, Heilbron or Beilstein, they will provide references to the original synthesis papers. Note that large scale production techniques often use procedures that were developed later, and street procedures often are significantly different, usually due to financial, equipment, or chemical feedstock constraints. For the long answers, see the "alt.drugs Clandestine Chemistry Primer/FAQ" by Yogi Shan (yshan@nortel.ca), and visit some sites listed in the Network Resources FAQ available in alt.drugs. For a fairly comprehensive overview, ( but no warranty implied for info available there ), you could start at: http://hyperreal.com/drugs/ An interesting article on the link between methylenedioxymethamphetamine ( MDMA, ecstasy, XTC, Adam ) illegal synthesis and the sassafras tree is available [1]. 13.6 Should I post detailed recipes for illegal chemicals? Well, if you do a lot of people will hate you. On the other hand many people will love you. Of course, most people won't care one way or another. Or maybe they'll just roll their eyes back, mumble something about "dissipated/mis-spent youth", and hit the "next" button. Posting them to sci.chem means you will be attempting to teach grandmother how to suck eggs, most regulars of sci.chem *know* where to find the complete instructions, how to perform the synthesis, and have authorised access to all the equipment and chemicals. The readers of sci.chem are probably not your target audience, and may be a little annoyed that you had such a low opinion of their chemistry abilities. If you do not want a lot of flames, try posting to the groups in section 13.1, they will probably appreciate your contribution more, but will still flame you if it is wrong. This is Usenet, do what you want as long as you think you can get away with it. And don't ever let anyone tell you that you can't. It's a truism on Usenet that whatever you do, someone's going to be mad at you. For every anarchistic Free Spirit (TM), there's going to be at least one anal-retentive busy-body who has nothing better to do that feign outrage at something or other. Some idiot in Australia even had the nerve to flame me for posting my Clandestine Chemistry FAQ to sci.chem, and I think drugs are terrible, and said so. So go figure. The only caveat to this is that posting mis-information, or information that you personally do not understand, is likely to result in a lot of flames. If you attempt to post anonymously to sci.chem, it is likely that you will encounter far more opposition than if you use your email address. As with all of Usenet, posters who sign their names to posts will be held accountable for the content, so posting obviously incorrect or incomplete syntheses to a group where knowledgeable chemists hang out is more likely to harm your credibility. Your posts are unlikely to gain you further knowledge of the synthesis, because if you post incorrect details, readers will be pointed to the more accurate Clandestine Chemistry FAQ, and also directed to the groups in section 13.1 to find the latest details. In the late 1980s, and early 1990s a poster began to post all the detailed synthesis methods from Pihkal to sci.chem. "Pihkal" is Alexander and Ann Shulgin's standard text " Phenethylamines I Have Known and Loved [2a]", which has recently been supplemented with "Tihkal" ( Tryptamines I have Known and Loved ) [2b]. From vague memory, the poster was just listing the recipes, and not entering into discussions or responding to questions or comments. There was the usual outrage, but I believe he had to stop because of copyright violation of the book he was posting - he could not demonstrate to his access provider that he had approval from the copyright holder :-). Shulgin has now made Part Two of PiKAL freely available, and copies are littered around the Internet, so check out the various alt.drugs FAQs for their location. 13.7 What newsgroups/mailing lists discuss explosives? Rec.pyrotechnics and alt.engr.explosives are two newsgroups that discuss explosives, much to the consternation of some subscribers to the former. The rec.pyrotechnics FAQ is excellent, and is posted regularly to rec.pyrotechnics, news.answers, and rec.answers. There's an "Anarchist Cookbook FAQ" posted semi-regularly to rec.pyrotechnics and alt.engr.explosives that tells you why the AC is lousy. See also: http://www.cwi.nl/cwi/people/Jack.Jansen/spunk/cookbook.html This review goes a little overboard: the mercury fulminate and picric acid recipes the he refers to are fine by my estimation. See also [but no warranty implied for info available on]: http://paradox1.denver.colorado.edu http://www.wiretap.spies.com 13.8 What is the chemical structure of common explosives? Exothermic oxidation-reduction reactions are the source of energy, and they can be produced from mixtures of discrete fuels and oxidisers, or from molecular decomposition - such as from nitroglycerine. Propellants and explosives produce large volumes of gases, whereas pyrotechnics do not. Gas Reaction Ignition Volume Heat Temperature (cm3/g) (MJ/KG) (C) Photoflash (30:40:30 Ba(NO3)2:Al:KClO4) 15 8.989 700 TNT 710 4.560 310 Most explosives are organic compounds or mixtures that contain carbon, hydrogen, oxygen and nitrogen. Metallic fuels ( eg aluminium ) may be added to increase the heat of reaction. Industrial dynamites traditionally used nitroglycerine, nitrocellulose, and inorganic salts as sources of oxygen, but these have been replaced by formulations that use ammonium nitrate as the primary oxygen source. Note that the specific energy is usually lower than the combustion of common fuels in air because the fuels obtain their oxygen from air. Many explosive can either burn or detonate, usually depending on the type of initiation, confinement, and physical properties of the fuel. When initiated, burning first occurs at an increasing rate during the first few microseconds as it creates a high velocity, high pressure shock wave that exothermically decomposes the explosive as it passes. The wave is sustained by the transfer of energy from the reacted explosive to the unreacted explosive via shock compression. The reaction rate depends on the rate of propagation of the shock wave, rather than the rate of heat transfer - as occurs during burning. Explosives are usually classified into: Low Explosives or Propellants eg colloidal cellulose nitrate ( smokeless powder ), black powders, gun and rocket propellants. - they are usually mixtures of chemical compounds that produce large volumes of high temperatures gases at controllable rates, and do not require atmospheric oxygen. Ammonium perchlorate and ammonium nitrate are commonly used as oxidisers. Initiating or Primary Explosives ( detonators ) eg lead azide, mercury fulminate, diazodinitrophenol (DDNP). - they are used to initiate the next component of an explosive chain, and are usually dense, organometallic compounds. - these are sensitive materials and fairly dangerous to handle as they can be ignited by heat, shock and electrostatic energy. Lead Mercury DDNP Azide Fulminate Density (g/cm3) 4.0 4.2 1.60 Heat of Combustion (MJ/KG) 2.64 3.93 13.58 Heat of Detonation (MJ/KG) 1.54 1.79 3.43 Gas Volume (cm3/g at STP) 308 316 876 Detonation Velocity (m/s) 5100 5400 6900 High or Secondary Explosives There is a distinction between secondary and high, however many of the common explosives are considered "secondary high explosives". eg cyclotrimethylenetrinitramine (RDX), 2,4,6-trinitrotoluene (TNT), cyclotetramethylenetetranitramine (HMX), ammonium picrate (AP). "Secondary explosives" include trinitrophenylmethylnitramine (Tetryl), nitrocellulose (NC) nitroglycerine (NG), pentaerythritol tetranitrate (PETN), and nitromethane. High and secondary explosives require explosive shock to initiate their detonation, otherwise they would only burn if unconfined or unshocked. NG TNT AP RDX HMX Tetryl Density (g/cm3) 1.59 1.65 1.72 1.85 1.90 1.70 Heat of Combustion (MJ/KG) 6.80 15.02 12.09 9.46 9.88 12.24 Heat of Detonation (MJ/KG) 6.29 4.23 4.31 4.54 5.67 4.63 Gas Volume (cm3/g) 715 710 680 780 755 760 Detonation Velocity (m/s) 7600 6940 7050 8570 9160 7920 Detonation Pressure (GPa) - 18.9 - 33.8 39.3 26.2 RDX and HMX are substantially desensitized when mixed with TNT or coating with polymer/elastomer binders. Most RDX in the USA is converted into "Composition B" (59.5:39.5:1 RDX:TNT:Wax) "A5" (98.5:1.5 RDX:Stearic Acid) "C4" (91:5.3:2.1:1.6 RDX:dioctyl sebacate:polyisobutylene:oil). Amatol AN B 80/20 C4 AN ANFO Slurry Density (g/cm3) 1.72 - 1.64 1.72 0.93 1.40 Heat of Combustion (MJ/KG) 11.67 4.19 - 2.62 - - Heat of Detonation (MJ/KG) 5.28 4.10 6.61 2.63 3.76 3.05 Gas Volume (cm3/g) - 860 - 980 - - Detonation Velocity (m/s) 7900 5200 8340 2700 4560 6050 Detonation Pressure (GPa) 29.5 - 25.7 1.1 6.0 10.4 Note that explosives usually have less potential energy than gasoline, but it is the high rate of energy release that produces the blast pressure. TNT has a detonation velocity of 6,940 m/s compared to 1,680 m/s for the detonation of pentane in air, and the 0.34 m/s stoichiometric flame speed of gasoline combustion in air. Other than ammonium nitrate/fuel oil (ANFO), most common explosives are trinitrated organic compounds. Nitroglycerine (glyceryl nitrate), trinitrotoluene (TNT), picric acid, C4 (plasticized RDX/Cyclonite), and tetryl (2,4,6-trinitrophenylmethylnitramine), fall into this category. Refer to Merck or Kirk Othmer for chemical structures of common explosives. A range of Semtex plastic explosives were produced by the Semtin Glassworks in Czechoslovakia ( now known as VCHZ Synthesia ). Semtex-H is commonly used by terrorists and, although examples are of variable composition, it typically contains approximately 8% oil, 9% rubber, and approximately equal quantities of RDX and PETN, but with known composition ranges of >21.5% RDX and <64.5% of PETN. [3,4]. ANFO was proposed in 1867, but it was the development of anti-caking agents in the 1950s that made ANFO suitable for rock blasting. Typical commercial ANFO blasting agents consist of 94% ammonium nitrate prills (coated with an anti-caking agent) and 6% fuel oil. They are reclassified as blasting explosives if the formulation is sensitised by the addition of high explosive. ANFO explosives are usually initiated by a high-explosive booster such as formulation B. Maximum sensitivity to initiation occurs around 2-4% fuel oil, with the presence of water decreasing sensitivity. The recent bomb in Oklahoma City (estimated 1800kg ANFO)[5], demonstrated the destructive capacity of ANFO explosives. There were solubility problems using ANFO in wet drill holes, so aqueous- based slurries were developed. These are usually thickened suspensions dispersed in a saturated salt solution that has been made water resistant by the addition of hydrophilic colloids that inhibit water migration. Ammonium nitrate-based explosives account for 97% of the US industrial explosives. The infamous nitrogen tri-iodide ( touch powder ) produced by the reaction of ammonia with iodine, is not actually NI3, but a nitrogen iodide/ammonia complex with the structure NI3(NH3)n where n = 1, 3, or 5 - depending on conditions. NI3 has only recently been isolated, and is stable at -196C, decomposes slowly at -78C, and decomposes spontaneously at 0C [6]. Refer to an older inorganic chemistry text, such as "The Chemical Elements and their Compounds"[7], for further details and references. Recently, there has been great interest in the development of more energetic materials, and several new compounds are expected to replace existing materials - once manufacturing costs are reduced. Examples include;- ADN (Ammonium Dinitramide - NH4N(NO2)2, used as a propellant by the Soviet Union), CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexazaisowurtzitane, aka HNIW, the most powerful single-component explosive known - which, when combined with a polymer binder is also known as LX19), and TNAZ (1,3,3-trinitroazetidine) [8,9,10]. 13.9 How do I obtain chemical information on common explosives? There is an excellent, well-referenced "Explosives and Propellants" monograph in Kirk Othmer [11] and there are also the popular books "Explosives" by Meyer [12], and "Chemistry of Powder and Explosives" by Davis [13]. Many of the relevant properties of fuels and explosives are found in an easily-accessible Bureau of Mines report "Investigations of Fire and Explosion Accidents in the Chemical, Mining, and Fuel-Related Industries - A Manual" by J.M.Kuchta [14]. There is also the "Propellants, Explosives and Pyrotechnics" journal. Merck lists most common, and many uncommon explosives, giving their structure, selected properties, and pointers to synthesis and more detailed information. Shreve and Kirk Othmer also discuss explosives manufacture. Tadeusz Urbanski wrote a massive four-volume reference set on explosives "The Chemistry and Technology of Explosives" [15] that should be available in any university science library (it's something like US$700 otherwise). The "Encyclopedia of Explosives and Related Items", aka "PATR 2700" (Picatinny Arsenal Technical Report) [16], is a U.S. Army (Picatinny Arsenal, Dover, NJ), all-encompassing compilation (10 volumes) of explosives properties and chemistry. Like Urbanski, it's also quite expensive. 13.10 What newsgroups/mailing lists discuss pyrotechnics? rec.pyrotechnics is the "official" newsgroup for fireworks/pyrotechnics discussions, though many have fled to the mailing lists due to the large numbers of juvenile "mad bomber" type posts that abound. Mark A. Buda < buda@star.enet.dec.com > The original rec.pyro exile fireworks list. "Mad Bomber" posts forbidden. The Pyro Mailing List is a "Real" pyrotechnic discussion group moderated by a pyrotechnician. No mad bombers. To subscribe apply to pml@vnet.net and follow the instructions. One must supply the info and there are reasonable guidelines to follow. Murr Rhame <murr@jazzmin.vnet.net> Show-Fire entertainment pyrotechnics mailing list. "Mad Bomber" posts forbidden. To subscribe send the following one line message to listserv@vnet.net: subscribe show-fire name@your.address Ken Harthun <omckenh@pipeline.com> PyroTechniques, The Newsletter for Pyrotechnic Enthusiasts. It is FREE for the asking. Just email me with a request to be added to the list. See also: http://mercury.aichem.arizona.edu/~tip/pyro.html http://nickel.ucs.indiana.edu/~flinn/pyro/pyro.html http://fireworks.com/ ------------------------------ Subject: 14. Academic Course Information 14.1 Where do I find information on US courses? The advent of the WWW has meant that many educational institutions now have their courses listed. A WWW search should reveal the address of most institutions, and several of the more popular chemical courses are linked to some of the general chemistry education sites listed in section 7.2. Note that most US educational institutions will have a *.edu (education) Internet address. Also check out the various Chemical Society homepages. 14.2 Where do I find information on other nations' courses? Once again, try using the WWW, as many educational institutions worldwide are placing course information on their home pages. It is worth remembering that not all countries use *.edu (education), as the educational institution address, some countries use *.ac (academic) eg vuw.ac.nz is Victoria University in Wellington, New Zealand. ------------------------------