WIXLIB

CONTENTS2.208Determination of trans-octadecanoic acids by thin-layer chromatography and gas—liquid2.209Determination of polyunsaturated fatty acids with a cis,cis 1 A-pentadienoic structureDetermination of fatty acids in the 2-position in the triglycerides of oils and fatsDetermination of the hydroxyl value (OH.V)Determination of epoxy-group 2.5012.5022.5032.5042.5052.5062.507Determination of the Principal ConstituentsPreparation of the fatty acid methyl estersGas—liquid chromatography of fatty acid methyl estersDetermination of n-3 and n-6 unsaturated fatty acids in vegetable oils and fats bycapillary gas—liquid chromatographyCapillary column gas — liquid chromatography of fatty acid methyl estersDetermination of butyric acidDetermination of erucic acidDetermination of linoleic acidDetermination of mono-, di- and triglycerides by column chromatographyDetermination of monoglyceridesDetermination of triglycerides by gas—liquid chromatographyDetermination of the composition of triglycerides in vegetable oils in terms of theirpartition number by high performance liquid chromatography (HPLC)Determination of the individual triglycerides in oils and fats by high performance liquidchromatographyDetermination of mono- and diglycerides by capillary gas chromatographyDetermination of the Other Natural ConstituentsDetermination of the unsaponifiable matterQualitative examination and determination of the total sterols by their digitonidesIdentification and determination of sterols by gas—liquid chromatographyDetermination of the total sterols contentIdentification and determination of tocopherols (ex 2.404)Determination of phophorusDetermination of the phosphoric acid test (PAT) value of raw linseed oilDetermination of phosphorus by direct graphite furnace atomic absorption spectrometryDetermination of the erythrodiol contentDetermination of tocopherols and tocotrienols in vegetable oils and fats by highperformance liquid chromatographyDetermination of the Quality and the StabilityDetermination of the peroxide value (P.V.)Determination of the oxidized acids' (insolubilization method)Determination of the oxidized acids' (thin-layer chromatographic method)Determination of the p-anisidine value (p-A.V.)Evidence of purity and deterioration from ultraviolet spectrophotometryDetermination of stability (the modified 'Swift test')Determination of polar compounds in frying fats

CONTENTS2.508Determination of polymerized triglycerides in oils and fats by high performance liquid2.53Determination of the 2-thiobarbituric acid value: direct 1Determination of the Foreign Substances and the AdditivesDetermination of the moisture and volatile matterDetermination of water (entrainment method)Determination of small quantities of water (modified Karl Fischer method)Determination of the insoluble impuritiesDetermination of ash contentDetermination of polyethylene type polymersDetermination of 'hexane' residues in fats and oilsDetermination of benzo[ajpyrene in edible oils and fats by reversed phase highperformance liquid chromatographyDetection of mineral oils in vegetable and animal oils and fatsDetection of propyl-, octyl- and dodecyl-gallates, butylated hydroxyanisole andbutylated hydroxytolueneDetermination of butylated hydroxyanisole and butylated hydroxytolueneDetermination of copper, iron and nickel by direct graphite furnace atomic absorptionspectrometryDetermination of lead by direct graphite furnace atomic absorption spectrometryDetermination of organochlorine pesticidesDetermination of antioxidants by high performance liquid chromatographyDetermination of Fats in Related CompoundsDetermination of total fat in margarinesSection 3: 3.1373.138Determination of the Physical CharacteristicsDetermination of the relative density 20/20 in air and of the conventional mass per unitvolumeMeasurement of colour in Hazen units (platinum—cobalt scale)Determination of the Chemical CharacteristicsDetermination of alkalinity or acidityDetermination of the glycerol content (titrimetric method)Determination of the acidity and the saponification equivalentDetermination of Foreign Substances and AdditivesDetermination of water content (Karl Fischer method)Determination of ash contentDetermination of arsenic content (photometric method employing silverdiethyldithiocarbamate)Calculation of matter (organic) non-glycerol—MONGDetermination of the sulphated ash contentvii

CONTENTSSection 4: Alkaline Soaps4.2014.2024.2034.2114.2124.2 134.3014.3024.3114.3124.3 134.3214.3224.331Determination of the Chemical CharacteristicsDetermination of the total alkali contentDetermination of the free caustic alkali contentDetermination of the total free alkali contentDetermination of the 'total crude fatty acids' contentDetermination of the rosin contentDetermination of the unsaponified saponifiable unsaponifiable matter content, of theunsaponifiable matter content, and of the unsaponified saponifiable matter contentDetermination of Foreign Substances and AdditivesDetermination of the free glycerol content (titrimetric method)Determination of low free glycerol content (spectrophotometric method)Determination of moisture and volatile matter content (oven method)Determination of the water content (azeotropic distillation method)Determination of the ethanol-insoluble matter contentDetermination of the chloride contentDetermination of the chloride content (potentiometric method)Determination of the EDTA (sequestering agent) content (titrimetric method)Section 5: Lecithins5.2015.2055.3015.302Determination of the Chemical CharacteristicsDetermination of the acidity of lecithins (ex 2.201)Determination of the iodine value (ex 2.205)Determination of the Principal ConstituentsDetermination of phospholipids by thin-layer chromatography and phosphorus analysisDetermination of the phospholipid profile of lecithins by high performance mination of Other Natural ConstituentsDetermination of the phosphorus content of lecithins (ex 2.421)Determination of the Quality and the StabilityDetermination of the peroxide value (ex 2.501)Determination of the acetone-insoluble material in lecithinsDetermination of the Foreign Substances and the A dditivesDetermination of small quantities of water by modified Karl Fischer method (ex 2.603)Determination of the toluene-insoluble material in lecithinsSection 6: Emulsifiers6.()1Determination of the ester-emulsifiers components after hydrolysis and silylation by gas6.002Determination of mono- and diglycerides by capillary gas chromatography (method2.326)chromatography

COMMISSION ON OILS, FATS AND DERIVATIVESlikewise, the revision of Sections III (Glycerines) and IV (Soaps) proceeds, while thepreparation of further Sections is in hand.So we have good reason to claim that the Commission on Oils, Fats and Derivativescontinues its efforts to be useful to all.C. PAQUOTPresident of the Commission onOils, Fats and DerivativesOnly eight years have elapsed since the publication of the 6th edition of our Methods.During this period, which though short, has been none the less rich in activities andresults, life of the Commission on Oils, Fats and Derivatives may be summed up asfollows, by the rhythm of the meetings, which have taken place yearly.At the 1977 Warsaw meeting, C. Paquot became Chairman, assisted by E. Delvaux,Vice-Chairman, and A. Hautfenne, Secretary. After Brussels in 1978, the Commissionmet in Davos (Switzerland) in 1979 where E. Delvaux retired having reached theuniversity age limit.The 1980 Paris meeting gave the opportunity of celebrating the 50th anniversary ofthe Commission.In Leuven (Belgium) in 1981, C. Paquot gave up the Chairmanship to D. Firestone;M. Naudet became Vice-Chairman, A. Hautfenne keeping the Secretariat. In order toconform to the Statutes and by-laws of the Union, the Commission was obliged toreduce to six the number of its Titular Members but was authorized to bring to twelvethe number of its Associate Members.After Zeist (The Netherlands) in 1982, came Lyngby (Denmark) in 1983, when M.Naudet succeeded D. Firestone as Chairman, A. Hautfenne became Vice-Chairman andW.D. Pocklington became responsible for the Secretariat.After its meeting in 1984 in Turku (Finland), the Commission met in Lyon (France)in 1985.During this period, the Commission has seen the number of represented countriesincrease very significantly: in 1979, Brazil, Finland and Yugoslavia (until 1981) rejoinedthe Commission but Norway left; in 1981 Argentina rejoined, after an absence of fouryears, together with Egypt, Romania, South Africa and the USSR; Israel and Malaysiajoined in 1983.During the same time, several changes arose among the Members of the Commissionmainly due to modification or ceasing of activities. Unfortunately one must also mentionthe death of two very long-serving Members: Mrs E. Lewkowitsch-Morton and K.Williams.Revision of methods included in Sections III and IV of the 5th edition has beencompleted and the revised texts have been published in Pure and Applied Chemistry(PAC) as Supplement to the 6th edition. Fifteen new methods have been investigated,adopted and drafted. They have also been published in PAC and they are incorporatedin the present edition.About twenty other methods are already at the final draft stage or are only investigated. After their adoption and drafting, they will be published in PAC with thestatistical report relating to the collaborative study.xv

COMMISSION ON OILS, FATS AND DERIVATIVESThe Commission has strengthened existing bonds and has created new ones withseveral international organizations by means of a constant collaboration and exchange ofobservers.The general objectives assigned to the Commission on Oils, Fats and Derivativescontinue to be pursued energetically, thanks to the dedication of all its members.M. NAUDETJanuary 1985Chairman of the Commission onOils, Fats and Derivatives1985—1990In the 5 years that have elapsed since the 7th edition was prepared for publication therehas been a significant number of changes in the membership of the Commission. Unfortunately, both C. Paquot and A. Hautfenne (who together undertook the prodigioustask of preparing the 7th edition for publication) have been unable to continue as activemembers of the Commission. In 1985, M. Naudet (France) relinquished the chairmanship to O. Levin (Sweden) who, in turn, was replaced by Mrs J. Beare-Rogers (Canada)who officiated from 1987 until 1989.Following the 1985 meeting in Lyon (France), 1986 saw the Commission meeting inVienna. The year of 1987 was noteworthy for the Commission in that two meetings wereheld that year—the first at Münster (Germany) in July and the second at Boston (USA)in August. The Münster meeting was essentially a meeting for the European members ofthe Working Groups who could not go to Boston. St. Andrews (Scotland) was the venuefor the 1988 meeting, and the 1989 and 1990 meetings took place, respectively, in Lund(Sweden) and Montreux (Switzerland).It is to be regretted that a few countries have ceased to be represented on ourCommission, but the introduction of the IUPAC Affiliate Membership Scheme augurswell for the future since we now have affiliate members from a number of countries notrepresented as full members, i.e. China, Ethiopia, Kenya, Indonesia, Peru, the Philippines and Sri Lanka.The Commission continues to enjoy the coveted status of being one of the mostactive IUPAC Commissions, and this activity is reflected in the standardization duringthe past 5 years or so of some 20 new methods for the analysis of oils, fats andderivatives. These new methods have been published as the 1st Supplement to the 7thedition of the Standard Methods for the Analysis of Oils, Fats and Derivatives.W.D. POCKLINGTONJanuary 1991xviChairman of the Commission onOils, Fats and Derivatives

Warningof the methods require theutilization of particularly flammableand/or poisonous solvents.Included in these solvents are: benzene,carbon tetrachloride and chloroform.In these cases, the safety instructionsfor the handling of these solvents should bestrictly observed.The procedure must be carried out in awell-ventilated room, preferably in a fumecupboard, to prevent the exposure oflaboratory workers to poisonous vapours.The IUPAC Commission VI.3 hasembarked on a programme with theobjective of reducing, as far as ispracticable, the need for use of suchsolvents in its standard methods.Somexvii

Quality assurance (analytical quality control)General principlesIntroductionThe number of test results to be obtained from the analysis of each laboratory sample isrelated to the purpose for which the analysis is required. Where the analysis is requiredunder the terms of a contractual agreement, or for arbitration purposes, more than onetest result for each analyte/parameter may be required. In routine quality control it maybe considered adequate to obtain a single test result for each analyte/parameter. However, for analytical quality control purposes, an analysis in duplicate will be necessary forat least one in every ten determinations of each analyte/parameter.Precision of analysesWhen a check on the precision of the analyses is required, two test results for each testsample must be obtained under the conditions of repeatability (i.e. conditions whereindependent test results are obtained with the same method on identical test material, inthe same laboratory by the same operator using the same equipment, within shortintervals of time). (Note: It may also be desirable to obtain two test results underintermediate precision conditions (e.g. when operator and equipment are the same buttime is different).)Acceptability of test resultsWhen two test results are obtained (under the conditions of repeatability) from twoanalyses of the same test sample, the final quoted result is the mean of the two testresults, provided that the requirements of the repeatability clause are met—see thesection on specific applications of analytical quality control which is appended to the textof the method. If these requirements are not met, reject the results and obtain twofurther test results (under repeatability conditions). If the requirements of the repeatability clause are again not met, an investigation into the possible sources of error shouldbe carried out. If the source of error cannot be found, the procedure for deriving thefinal quoted result, illustrated in the annexed flow diagram, may be followed. In such acase the final quoted result should be qualified with a statement to the effect that theconditions of repeatability were not met, and the individual test results (with an indication as to how the final quoted result has been calculated) should also be reported.Utilization of values for the reproducibility limit (R)When test results obtained by two laboratories (from the analysis of identical laboratorysamples) are being compared, it should be noted that the values for (R) [determinedaccording to ISO 5725} apply in the particular case when each laboratory obtains onetest result only. If it is desired to compare final quoted results, which are the mean resultsfrom more than one analysis carried out by each laboratory on identical laboratorysamples, the appropriate values for (R) can be calculated as outlined in the 1987—IUPAC Harmonized Protocol or ISO 5725 Part 6 Section 2. For example, when the finalquoted results are the mean results from two analyses carried out by each laboratory, theformula below applies:R where:xviii\/(R2 — r2/2)

QUALITY ASSURANCER is the adjusted value for the reproducibility limit, applicable when the final quotedresults are the mean results from two analyses carried out by each laboratory onidentical laboratory samples;R is the value for the reproducibility Iimit* of the method; andr is the value for the repeatability limit* for the method.Trueness of test resultsWhen a check on the trueness of the test results is required, one or more certified(purchased or prepared in-house) reference materials, of similar matrix and analyteconcentration to that of the test samples, should be analysed in parallel with the testsamples. A decision is then made as to whether the difference, if any, between theexpected value(s) for the reference material(s) and that obtained by analysis of thelatter, is statistically significant, in the case of:(a) certified reference materials—by reference to the cited confidence limits, or(b) prepared in-house reference materials—by use of plotted data such as that on controlcharts. In this case a test result obtained for the prepared reference material which fallswithin 2 units of the standard deviation (s)* of the accepted mean value* for theanalyte of interest may be considered acceptable. If the difference between the testresult and the mean value exceeds 3s the test result must be rejected. *(Note. Theaccepted mean value and standard deviation would be that calculated from the resultsobtained from not less than ten analyses of the prepared in-house reference material.Lines drawn on the control chart at 2s and 3s both above ( ) and below (—) the linerepresenting the mean value are regarded as warning and action limits, respectively.)A check on consistent method and individual laboratory bias may be made by spikingand determining the recovery of added analyte.AnnexeStart withtwotest results (, x2)(x1 x2 (/2,LL(x1 Xz Xv X4 )1I No,' medianof (x ,x2, x3, x4) [i.e. ( x 2 x3 )/2(where x2, x3 ore, respectively, the second and third smallest test results)Flow diagram illustrating thederivation of the final quoted resultwhen test results do not meet theconditions of repeatability. r repeatability limit for the method;1 final quoted result, [Note: Theflow diagram is based on thatappearing in Section 7 Part 6 ofiso 5725 (long-term revision).]ReferencesHorwitz W. Pure .4ppI Chem 19S8: 60(6): 855-867.Pocklington WD Pure tlpJIl ('hem I 990; 62(1) I 49 162.Determined according to the 1987—il]PAC Harmonized Protocol or 150 5725 from a statistical analysis ofthe results obtained during the collaborative study of the method.xix

2.201 Determination of the acid value (A.V) and the acidityStatistical evaluation of results of study carried out in 1989.Palm oilrefinedNumber of laboratoriesNumber of resultsNumber of laboratories retained after deletion of outliersNumber of accepted resultsRepeatability (r)*Reproducibility (R)** Expressed as the percentage of oleic acid; acid value 22.201/1Fish 25Mean value (% oleic acid)Repeatability standard deviation *Repeatability relative standard deviation (%)Reproducibility standard deviation*Reproducibility relative standard deviation (%)Palm oilcrudex acidity.50.85

2.205 Determination of the iodine value: Wijs' methodStatistical evaluation of results of studies carried out in 1989/90.Table 2.205.1.Mean valuer—RCHXCTCCHX3.67.24.8(20. 20)1.431.90(20, 20)4.352.80(18, 14)5.272.754.323.10(14. 12)(20, 20)(12. 16)Solvent:*CTC CHX CTCSampleSunflower seed oilPalm oil, refinedFish oil. 40Tung oilTallow (beef fat)Soyabean oil, 1.861.3313.8Palm oil, crudeFrying oil, usedFish oil, hydrogenated52.537.7n3.352.637.768.6Palm kernel oilOlive .642.62No. of accepted

Analysis of the Oil Extracted from the Seeds and Fruits 1.151 Determination of acidity of oil Analysis of the Residues Remaining after Oil Extraction 1.171 Determination of total hexane content in extraction meals 1.172 Determination of free' hexane content in extraction meals