bluuebunny/crossref_metadata_2025 huggingface dataset:
Separation of Acetylcodeine from Illicit Heroin by Thin Layer Chromatography
Authors: Nakamura George R
Published: February 2020

The presence of acetylcodeine as an impurity in illicit heroin preparations has been demonstrated by the detection of codeine in hydrolyzed samples. The method described here, using thin layer chromatography, showed that acetylcodeine per se can be separated from illicit heroin and that it can be used as a basis for screening such illicit preparations for acetylcodeine.
Ultraviolet Determination of 2-Pivalyl-l,3-indandione (Pival) and Its Sodium Salt in Rodenticide Formulations
Authors: Griffin Travis B , Blazek Nancy A
Published: February 2020

An ultraviolet spectrophotometric method for 2-pivalyl-l,3-indandione in finished rodenticide baits involves extraction of the bait with a glycine-sodium hydroxide buffer, acidification with trichloroacetic acid, and extraction into cyclohexane with 0.5JV sodium hydroxide. Interfering substances were removed by chloroform. The absorbances were measured at 283 and 319 mμ in an ultraviolet spectrophotometer, and the rodenticide content was calculated by a modified base point technique. Quantitative recoveries were obtained when model baits were analyzed.
Laboratory Variations in the Analysis of Fertilizers
Authors: Quackenbush F W , Rund R C , Miles S R
Published: February 2020

Five carefully prepared mixtures of fertilizer-grade chemicals were analyzed by 23 laboratories under routine circumstances in which the laboratory personnel were unaware that they were participating in a research study. The experiments were designed to observe variations within and among laboratories when heterogeneous samples were reduced and analyzed according to the usual laboratory routine: first, as compliant samples (meeting a guarantee); and second, as deficient samples (below a guarantee). The individual analyses in the study totaled 2,242. In addition to the data on variation within and among laboratories, the observations provided information on bias, both in the analysis and in the reporting of results by the administrator of the laboratory.
Two-Dimensional Thin Layer Chromatographic Procedure for the Identification of Dye Intermediates in Arylamine Oxidation Hair Dyes
Authors: Kottemann Christine M
Published: February 2020

Dye intermediates in arylamine oxidation hair dyes are identified by a two-dimensional thin layer chromatographic method. An initial development in basic solution is followed by development in an acidic solution. The dye intermediates are identified by their color reactions with spray reagents and by their spatial relationships to known intermediates developed on the same plate. The chromatographic study included 30 dye intermediates proposed for use in commercial oxidation-type hair dyes.
Routine Determination of Carbaryl in Dipping Fluids and Deposits on Cattle Hair
Authors: Dingle J H P
Published: February 2020

Sampling techniques and an ultraviolet method, capable of handling large numbers of samples, have been developed for carbaryl in dipping fluids and cattle hair deposits. The absorbance (280 mμ) of dip samples is measured after suitable dilution with ethanol; a correction is made for the presence of 1-naphthol, but background interference from dip dirt, clay, cow dung, etc. is negligible at the dilutions used. The amount of carbaryl deposited on cattle hair dipping is estimated similarly after extraction with ethanol. The accuracy of the dip analysis and the effect of hair grease on the analysis of hair deposits are discussed.
A Versatile Procedure for Assay and Preparatory Separation of Aflatoxins from Peanut Products
Authors: Eppley Robert M
Published: February 2020

A procedure in which the direct extraction of a water-wetted sample by chloroform is combined with the use of a silica gel column for defatting and cleanup has been devised for obtaining clean quantitative extracts of aflatoxins from 50 g and 1 kg peanut product samples. The method is rapid; the manipulations are easy and uninvolved. The low level of interference permits the detection and estimation of as little as 1 μg aflatoxins/kg of peanut product sample.
Comparison of Potassium Content of Fertilizers by Atomic Absorption and Sodium Tetraphenylboron
Authors: Mccrackan M L , Webb H J , Hammar H E , Loadholt C B
Published: February 2020

Atomic absorption spectrophotometry is a rapid and simple screening method for determining potassium in fertilizers, especially when a large number of samples are processed. The potassium content of 1190 fertilizer samples was determined by both atomic absorption (4038Å) at a dilution of 1:400 and by the sodium tetraphenylboron method; correlation between the two methods was significant (r = 0.96). Triplicate analyses of 101 samples by each method showed precision of 0.229% by STPB and 0.424% by atomic absorption; standard deviation of the difference between the two procedures was 0.50%. Other elements normally found in fertilizers did not interfere at 4038Å.
Ultraviolet Spectrophotometric and Gas Chromatographic
Methods for Ronnel in Feeds
Authors: Gehrt Albert J
Published: February 2020

Two new methods for ronnel in feeds at levels of 0.035-0.60% ronnel were developed and studied by 10 collaborators. Methods involve extraction of the sample (with chloroform for ultraviolet measurement or with acetone for gas chromatographic measurement) followed by Florisil cleanup of the extracts. Both methods measure true ronnel. The described methods are simpler and give better ronnel recoveries (92— 105%) than the present official, first action steam distillation method. Agreement between laboratories was good; coefficients of variation were 4.1—11.1%. Several collaborators encountered difficulty with Florisil cleanup at the low level (0.03% ronnel). It is recommended that study be continued on the standardization of Florisil
Disk Electrophoresis Method for the Identification of Fish
Species
Authors: Thompson R R
Published: February 2020

A collaborative study was made of a disk acrylamide gel electrophoresis method for identifying fish species through the use of characteristic protein bands. Results were generally satisfactory; 6 of 7 collaborators agreed on all samples. It is recommended that the method be adopted as official, first action
Collaborative Study of Capillary Viscometer Method for
Consistency of Fruit Nectars and Fruit Juice Products
Authors: Lamb Frank C
Published: February 2020

Collaborative results were obtained from 12 analysts from 9 laboratories, using the capillary viscometer on samples of apricot, peach, and papaya nectars and on pineapple- grapefruit and pineapple-pear fruit juice drinks. Each analyst reported triplicate results on 2 individual canned samples of each product. With the exception of one analyst, satisfactory agreement was obtained on all of the samples. Standard deviations varied from 2 to 4.6% of the actual readings. Variability was least for samples of apricot and peach nectar and the pineapplegrapefruit drink and greatest for the papaya nectar, probably due to can-to-can variation. The capillary viscometer method is accurate for measuring the consistency of fruit nectars and other fruit juice products, The method was recommended for adoption as official, first action
Paper Chromatographic Detection of Adulteration in Concord
Grape Juice
Authors: Fitelson J
Published: February 2020

Paper chromatography of the anthocyanidins, the phenolic components of the anthocyanins, is the most satisfactory means of detecting adulteration of Concord grape juice with other red grape juice and colored Italian grape skin extract. The 5 aniliocyanidins found in grape colors can be readily separated into 3 spots by paper chromatography. In the proposed method, anthocyanins are separated by lead precipitation, dissolved in water, and acid-hydrolyzed to obtain the anthocyanidins. Thirty Concord samples, 7 red grape juice samples, and 5 Italian grape skin extracts were examined and results were good. Four unknown samples were analyzed by 5 collaborators; all collaborators correctly detected the adulterated sample and the pure Concord sample. This method was recommended for adoption as official, first action
Use of Gas Chromatography in Distillery Research and Control
Authors: Debecze G I , Smith H F , Vaughn T E
Published: February 2020

Twelve volatile components commonly present in many whiskies can be determined directly by gas chromatography on four columns vinder specified conditions. Separalion and measurement of higher alcohols, separation of acetone from ethyl formate, measurements of four esters present, and proof of the absence of several components previously suspected to be present in distilled alcoholic beverages are described. Numerical values corresponding to the peaks are given for the components. Gas chromatograms combined with conventional chemical analysis give the best identification of bottled goods
Collaborative Study of a Method for the Identification of Afiatoxin B1 by Derivative Formation
Authors: Stoloff Leonard
Published: February 2020

A modification of the Andrellos procedure for identification of afiatoxin B1 was studied collaboratively in 19 laboratories. The procedure, based on the altered chromatographic behavior of the afiatoxin after reactions with trifluoroacetic acid, formic acid/thionyl chloride, and glacial acetic acid/thionyl chloride, was modified by an improved silica gel column cleanup and a clearer definition of sources of difficulty. Each collaborator examined 3 extract samples: two naturally contaminated with 5 μg afiatoxin B1/sample, and one aflatoxin-free extract to which an afiatoxin B2 artifact was added. No false identifications were made. Sixteen laboratories obtained reasonably good results with the trifluoroacetic acid and formic acid/thionyl chloride reagents. Twelve laboratories obtained reasonably good results with the acetic acid/thionyl chloride reagent but there was general difficulty with a side reaction assumed to be caused by inability to maintain anhydrous conditions. The method was recommended for adoption as official, first action.
Identification of Bullet Holes by Residue Transfer
Authors: Schlesinger H L , Hoffman C M , Pro M J
Published: February 2020

Antimony and copper residues deposited on the bullet surface after explosion of a pistol cartridge were measured by neutron activation analysis. The amount of residue wiped from the bullet surface upon passage through various target materials was determined. Correlations were found between the residue deposited on the target material and the bullet jacketing, caliber, and configuration
Residues in Poultry Tissues from Low Level Feeding of Five
Chlorinated Hydrocarbon Insecticides to Hens
Authors: Cummings J G , Eidelman M , Turner V , Reed D , Zee K T , Cook R E
Published: February 2020

Lindane, heptachlor epoxide, dieldrin, endrin, and DDT were fed in combination at 3 levels (0.05, 0.15, and 0.45 ppm) to hens, and residues were determined in abdominal fat, breast muscle, and livers by electron capture gas chromatography. Tissue samples were taken from birds at each feeding level and a control at regular intervals during a 5-month period which included 2 weeks pre-fortification, 14 weeks on the fortified feed, and 1 month withdrawal. Graphic data on fat and breast muscle show the increase of residues with time to an approximate plateau and the rate of decline. The greatest storage was in the fatty tissue where dieldrin and heptachlor epoxide attained a level approximately ten times the respective levels in the feed; endrin, p,p'- DDT, and lindane stored to a lesser degree. All residues in breast tissue were < 0.1 ppm, but the feeding levels were clearly delineated. AH residues in liver were < 1.0 ppm. The respective storage tendencies of the pesticides were the same in all tissues. A significant increase in the DDT metabolites, DDE and DDD, were observed. Lindane residues showed the greatest decline rate.
Determination of Aphids in Hops
Authors: Wright R G
Published: February 2020

The flotation procedure for determining aphids in hops has been improved over the previously described method (Method A, This Journal, 45, 670 (1962)) by the addition of an iodine staining technique to increase visibility of the aphids and a change in the counting procedure to include, as a whole aphid, any aphid part containing a head
Detection of Leaf Miners in Canned Spinach and
Turnip Greens
Authors: Brown Robert F
Published: February 2020

Comparative analyses with existing flotation and heavy filth methods indicate that a sieving, staining, and bleaching technique will give higher yield of spinach leaf miner and certain other arthropod filth. However, in some cases aphids were recovered in greater quantity with the flotation procedure. The sieving, staining, and bleaching technique is less laborious and less timeconsuming than the other methods studied
Improved Infrared Method for Carbaryl (Sevin) in
Commercial Formulations
Authors: Kovacs Martin F
Published: February 2020

The method described measures the infrared absorption bands of carbaryl at 5.75 and 8.94 ji after extraction from commercial formulations with chloroform. The products analyzed include Sevin as 5% dust, 50% dust, 50% wettable powder, and 85% sprayable powder. This method is recommended for adoption as official, first action
Collaborative Study of a Titrimetric Method for the Assay of
Amitrole Formulations
Authors: Bishop J Russell
Published: February 2020

titrimetric method for the assay of dry and liquid amitrole formulations was studied by 10 collaborators. In the method, acid is added to the prepared amitrole sample, the solution is titrated potentiometrically with standard alkali, and the amitrole content is measured as the amount of alkali consumed between the first and second inflection points. Collaborative results on standard samples of a dry 90% formulation, a dry 50% formulation, and a liquid 2 lb/gallon formulation showed good agreement between samples and laboratories. Statistical analyses of the results were satisfactory, and the method for the assay of amitrole formulations is recommended for adoption as official, first action
Separation, Identification, and Measurement of DDT and Its
Metabolites
Authors: Siewierski Marie , Helrich Kenneth
Published: February 2020

A system that combines gas and thin layer chromatography with infrared spectrophotometry has been devised for the separation, quantitation, and tentative identification of DDT and twelve of its possible reaction products. The system gives satisfactory results by all three methods and is valuable for investigation of the fate of DDT
Method for Residues of Zytron,® O-2,4-Dichlorophenyl O-methyl isopropylphosphoramidothioate, in Chicken Tissues and Eggs
Authors: Ivey M C , Claborn H V , Brinkman Barton
Published: February 2020

A gas chromatograph equipped with an electron capture detector provided a highly sensitive method for determining residues of the phosphorothioate Zytron in eggs and in the body tissues of chickens. An extraction and cleanup procedure made possible the detection of 0.005 ppm of Zytron and gave recoveries of 86—95% from the various tissues.
Quantitative Determination of Isoniazid (INH) and p-Aminosalicylic Acid (PAS)
Authors: Turczan John W
Published: February 2020

A procedure has been developed for the analysis of a combination of PAS with INH in tablets. This procedure is faster and more specific than the current AOAC assay. In the method, finely powdered tablets are dissolved in methanolic HCl. INH is determined by polarography, and PAS is determined by UV spectrophotometry.
Determination of Hydrocodone in Mixtures with Antihistamines
Authors: Doyle Thomas D
Published: February 2020

A modification of the official method for the analysis of hydrocodone in mixtures was studied collaboratively in 1965, but the results were invalidated by deterioration of hydrocodone in the sample sirup. The present study was designed to prevent this deterioration. Seven of the 9 collaborators report recoveries averaging 99.9%. The method is recommended for adoption as official, first action.
Infrared Determination of Piloearpine in Ophthalmic Solutions
Authors: Roberts James I
Published: February 2020

Official methods for piloearpine salts are aqueous and nonaqueous titrations that lack specificity. In the proposed method, piloearpine is extracted from the sample with chloroform and determined by infrared spectrophotometry with the absorbance maximum of 9 μ. Identity of the piloearpine is confirmed by comparing spectra of sample and standard between 5 and 11 μ. Recoveries of piloearpine from simple aqueous solutions of the nitrate ranged from 99 to 104%. Analysis of 9 commercial products declaring 0.5—4% piloearpine salt showed good precision between duplicates. Further study is recommended.
A Collaborative Study of the Analysis of Salicylic Acid and Benzoic Acid
Authors: Weber John D
Published: February 2020

A collaborative study was made on the analysis of benzoic acid and salicylic acid. The acids were separated by trapping salicylic acid on a ferric chloride-urea column and benzoic acid on a sodium bicarbonate column. Average recoveries were 101.9 ± 3.3% and 101.8 ± 3.0% salicylic acid and 100.5 ± 1.8% and 100.6 ± 1.8% benzoic acid for a liquid and solid sample, respectively. The method is recommended for adoption as official, first action.
Nuclear Magnetic Resonance Methods for the Analysis of Pharmaceuticals
Authors: Alexander Thomas G , Koch Stanley A
Published: February 2020

A collaborative study was conducted to determine the interlaboratory variation that would result from instrumental error alone. Six collaborators assayed sealed aliquots of solutions and measured peak areas by the instruments' electronic integrators. Average collaborative values deviated as much as 8% from the true value. Further work is recommended in an effort to reduce any deviation that may result from variation in either sample or technique.
Differences in Potassium Values Determined by Official AOAC Extraction Procedures
Authors: Rexroad Paul R , Gehrke Charles W
Published: February 2020

An investigation of a major difference in a special sample showed the reason for the potassium value differences in many routine fertilizer samples. Lower K2O values by AOAC official carbonate extraction method 2.079(a) as compared with AOAC official oxalate extraction method 2.070(a) were found consistently for 17 typical mixed fertilizer samples investigated. An average lower absolute difference of 0.4% K2O was found on the typical mixed fertilizers by carbonate extraction. Studies show that this difference is associated with the impurities in fertilizer grade phosphate raw materials, particularly the varying solubility of the (Fe,Al) (NH4,K,H) phosphates.
Gas Chromatographic Determination of Residual Hydrocarbon Solvents in Solvent-Extracted Edible Oils
Authors: Watts James O , Holswade Wendell
Published: February 2020

A rapid gas chromatographic survey method has been developed for the determination of residual hydrocarbon solvents potentially present in solvent-extracted edible oils. No prior cleanup or separation step is necessary. The oil samples are injected directly onto a GLC column containing 10% didodecyl phthalate liquid phase on 60—80 mesh Chromosorb P. Isomeric hexanes, isomeric heptanes, benzene, and toluene can be resolved in 25 minutes. Based on recovery studies, total residual isomeric hexane extraction solvent can be determined at 22—109 ppm with an average recovery of 92 ± 2.1%, and total residual isomeric heptane extraction solvent can be determined at 23—117 ppm with an average recovery of 90 ± 3.5% ; n-hexane and n-heptane are used as external standards. At the lowest levels of sensitivity, 22 ppm of total isomeric hexanes and 23 ppm of total isomeric heptanes, the observed average recoveries of 91 ± 2.5% and 92 ± 3.4%, respectively, are adequate. Although quantitative estimation is not practicable at lower levels, the presence of 10 ppm and probably less is discernible on the gas chromatograms. Quantitative recovery data for benzene and toluene have not been included, but the characteristics of their GLC peaks indicate the method is more sensitive for these aromatic impurities than for the aliphatic extraction solvents
Determining the Yeast Count in Maple Sirup and a Collaborative Study of the Methods and Sampling Techniques
Authors: Kissinger John C
Published: February 2020

Techniques for sampling and a method for determining the yeast count in maple sirup have been studied collaboratively in 22 laboratories. Statistical analysis of collaborators' results indicated that variation in shipping conditions had an adverse effect on the sirup samples and that difficulties in preparing homogeneous cell suspensions in the sirup prior to subsampling caused wide variation in counts. Studies will continue
Activity of Phenol, Ethyl Alcohol, and Isopropyl Alcohol in the AOAC Official, First Action Tuberculocidal Test
Authors: Shaffer C H , Ortenzio L F , Stuart L S
Published: February 2020

The reproducibility of results in the test procedure against the pure chemical phenol, using the test organism Mycobacterium tuberculosis var. bovis (BCG), was investigated. The method showed a remarkable degree of precision. The tuberculocidal activity of various concentrations of ethyl alcohol and isopropyl alcohol was also investigated, since these two chemicals have been widely used as tuberculocidal agents.
Collaborative Study of the Determination of uric Acid in Flour
Authors: Sen N P
Published: February 2020

A collaborative study of an enzymaticultraviolet method for determining uric acid in flour was made by 10 laboratories on 3 flour samples containing varied proportions of infested flour and one sample containing a known amount of added uric acid. The mean recovery of the added uric acid (16.91 mg/100 g) was 103%. The precision and accuracy of the collaborative results were within reasonable range for an enzymatic method.
Determination of Ascorbic Acid in Enriched Evaporated Milk
Authors: Pelletier O
Published: February 2020

Ascorbic acid can be determined in enriched evaporated milk by titration with 2,6-dichIoroindophenol. Most of the interfering substances are removed by precipitation with an acetic acid-metaphosphoric acid solution. Blank titrations obtained after condensing ascorbic acid with formaldehyde are used to correct for traces of interfering substances remaining in solution. Recoveries of ascorbic acid added to milk were 98.5% (coefficient of variation, 1.9). In a collaborative assay involving six analysts, the coefficient of variation was about 2% for one analyst on any day and 3.5% among analysts "on any day.
Procedure for Nine Organothiophosphate Pesticide Residues on Fruits and Vegetables, Using Microcoulometric Gas Chromatography
Authors: Nelson Richard C
Published: February 2020

A method, using microcoulometric gas chromatography (sulfur dioxide detector), is proposed for determining 9 organothiophosphate pesticide residues in fruits and vegetables. Extraction and cleanup principles and procedures are those used in the Mills-Onley-Gaither method for chlorinated pesticides, with modifications, particularly in the Florisil cleanup step. Recoveries of the compounds (sulfotepp, Thimet, diazinon, Di-Syston, methyl parathion, parathion, ethion, Trithion, and EI'IV) from crops fortified just prior to extraction ranged from 73 to 109%, with an overall average of 92%. Average recoveries of individual thiophosphates ranged from 82 to 99%. Recoveries were made at low (0.1— 0.2), intermediate (0.5), and high (2.0- 3.0) ppm levels. Cleanup on all crops tested was adequate for the detector used. In addition to the above compounds, malathion was quantitatively cluted from the Florisil column with an additional eluting mixture of higher polarity. Studies of the method should be continued to include both petroleum ether- and water-soluble compounds, and additional column packings will be investigated.
Benzoates in Foods
Authors: Lewis Matthew H , Schwartzman George
Published: February 2020

A collaborative study was conducted on a steam distillation-TLC method for benzoates in foods. Prior to measurement using 5 cm micro cells, the preservatives are separated from the food sample by steam distillation, and extracted from the distillate by CHCl3-ether shake-out. The samples were spotted on a thin layer plate (silica gel GF254 and kieselguhr G), the chromatogram was developed, and the material was recovered from the plate by extracting with ethanol. This procedure easily detects 0.1 ppm benzoate in foods. The method is recommended for adoption as official, first action with further work to be done on the determination of hydroxybenzoates, propionates, and other preservatives.
Improved Method for the Determination of Ethylenebisdithiocarbamate Residues in Plants, Fruits, and Vegetables
Authors: Gordon Charles F , Schuckert Richard J , Bornak William E
Published: February 2020

A modified method for the determination of dithiocarbamate fungicide residues on crops is presented. A large representative subsample of the frozen crop is blended in ice-cold deaerated water and an aliquot of the homogenate is added to the analytical apparatus containing hot 5 0% sulfuric acid. Dithiocarbamates are decomposed to evolve CS2 which is removed by a continuous gentle air-sweep from the digestion flask. Variations in technique allow the analysis of dithiocarbamate fungicide residues in several ranges, 1-10, 10-200, and 200-1000 /ig maneb. Recoveries from a wide variety of crops averaged 70 to 103%. Certain crop types present low recoveries and/or high apparent control values, but modifications in the analytical procedure are successful in solving these problems.
Preservatives: A Review of Methods of Analysis
Authors: Schuller Pieter L , Veen Eduard
Published: February 2020

This article presents a review of the most important methods of analysis which have been published during the last decade for the common preservatives sulfur dioxide, sorbic acid, nitrate and nitrite, and benzoic acid
Determination of l-Phenylazo-2-naphthol in D&C Red No. 17
Authors: Molitor John C
Published: February 2020

A thin layer chromatographic procedure is presented in which l-phenyIazo-2-naphthol (PAN) and an unidentified red substance are separated from D&C Red. No. 17 (l-p-phenylazophenylazo-2-naphthoI). PAN is dissolved from the absorbent and determined spectrophotometrically. Recoveries from samples of known composition ranged from 92 to 105%. The PAN content of commercial samples analyzed by this procedure ranged from 0.06 to 1.2%. Unsuccessful attempts to identify the red substance are discussed.
The New Florisil: A Statistical Evaluation For Chlorinated Pesticides
Authors: Beckman Herman , Carroll Kenneth , Thornburg Wayne , Vetro R I , Smith R D , Mittler Abe , Kecskes M B , Bevenue Arthur , Kawano Yoshihiko
Published: February 2020

A multi-laboratory study to evaluate the new Florisil PR was made with several chlorinated hydrocarbon insecticides and two representative crops. A computer program was used to analyze and compare the data between laboratories, between batches of Florisil PR, and between elution of standards alone and in the presence of crops. A comparison was also made of the elution patterns of "standard" Florisil and Florisil PR. Conclusions were drawn as to the most significant sources of error and the factors contributing to these. The computed data indicated that (1) there were greater differences in results due to variations between laboratories than due to any other cause; (2) greater differences in mean elution values were found when crop materials were present than with standards alone; (3) the least amount of variation observed was associated with differences between Florisil PR batches; and (4) six samples of "standard" Florisil showed that consistency of each batch was not always adequate for routine analysis
A Survey of Organic Chloride Impurities in Food Grade Hydrochloric Acid
Authors: Cummings J G , Zee K T
Published: February 2020

Results are given of a survey on organic chloride impurities in hydrochloric acid samples obtained from food manufacturing plants. Total organic extractible chloride found in the acids ranged from 3.9 to 10.2 ppm. A microcoulometric method of analysis for total chlorides was developed in which samples are extracted with petroleum ether, burned in a SchÖniger oxygen flask, and determined microcoulometrically. The more volatile impurities appear from GLC examination to be various common chlorinated aliphatics. No chlorinated pesticides were found
Determination of Molybdenum in Fertilizers by Atomic Absorption Spectrophotometry
Authors: Hoover William L , Dtjren Sonja C
Published: February 2020

A procedure for determining low levels of molybdenum in fertilizers by atomic absorption is proposed. With potassium thiocyanate as complexing agent, molybdenum is extracted in an isoamyl alcohol fraction to separate the fraction containing molybdenum from the water-soluble fraction containing materials that would interfere in the atomic absorption procedure. However, the procedure cannot be used with samples that have high concentrations of iron. Tests on the recovery of molybdenum in four fertilizers indicate that the procedure is reliable to levels as low as 2.5 ppm of molybdenum
Fatty Acid Composition of Palm Kernel, Illipe, and Shea Nut Oils by Urea Fractionation and Programmed Temperature Gas Chromatography
Authors: Iverson John L , Harrill Prince G
Published: February 2020

The detection of C6 to C28 fatty acids is possible when their methyl esters are concentrated by urea fractionation so that esters with similar gas chromatographic retention times are in different fractions. By modified programmed temperature gas chromatographic techniques, it is possible to detect and estimate fatty acids present in trace amounts (0.1 to 0.001%) in palm kernel, shea nut, and illipe oils. The odd and even chain length saturated fatty acids from C6 to C28 were detected. The odd and even chain length mono-unsaturates from C14 to C24 and the even chain length dienes from C14 to C24 were detected
Gas Chromatographic Determination of Chlormadinone Acetate in Feeds and Premixes
Authors: Koons J R , Scroggs R E
Published: February 2020

A method for determining chlormadinone acetate, a progestational steroid used for animal estrus control* involves extraction of the feed samples with dichloromethane and chromatography of the extracts on alumina to remove interfering materials. Extracts of premixes do not require purification. Chlormadinone acetate is measured by electron capture gas chromatography. Recoveries average 90 and 100% for feeds and premixes, respectively. Confidence limits (95%) for a single measurement on a sample (0.0022%) are ± 14%
Analysis of Preparations Containing LSD (N,N—Diethyl d—Lysergamide)
Authors: Martin Robert J , Alexander Thomas G
Published: February 2020

LSD (diethylamide of d-lysergic acid) can be detected by its fluorescence under ultraviolet light and by the production of a deep blue color when it is treated with a solution of p-dimethylaminobenzaldehyde and ferric chloride in sulfuric acid. LSD in an acid aqueous system has a peak maximum at about 312 m/j. This paper describes methods, adapted and modified in our laboratories, which are based on the above chemical properties of LSD. The methods include separatory funnel and column cleanup procedures, fluorescence tests, thin layer chromatography, separation of iso-LSD from LSD, and infrared identification
Assessment of the Naphthylazo-naphthylamine Method for
the Determination of Nitrate and Nitrite
Authors: Kamm Len , Bray D F , Coffin D E
Published: February 2020

The 1-naphthylazo-naphthylamine method for nitrate and nitrite, reported in 1965, was subjected to specific experiments statistically designed to determine more precisely the precision of the method. Experimental designs included the following: standard nitrite curve, stability of 1-naphthylazo- naphthylamino dye, reduction of nitrate to nitrite by the cadmium column, reproducibility of results comparing natural foodstuffs with pure solutions, and collaborative study on food samples. The statistical data obtained indicate that the method is consistent and precise
Analytical Procedures Used in FDA Laboratories for the
Analysis of Hallucinogenic Drugs
Authors: Martin Robert J , Alexander Thomas G
Published: February 2020

Various ultraviolet, infrared, and TLC procedures are described for the separation and identification of hallucinogenic drugs. Specific methods for LSD, DMT, and psilocybin are also presented, along with general background information for the hallucinogenic drugs.
Partition Chromatographic Assay of Opium and
Opium Preparations
Authors: Smith Edward , Levine Joseph , Banes Daniel
Published: February 2020

Application of column partition chromatography to opium extracts provides quantitative recovery of spectrophotometrically pure morphine. The extract is prepared by homogenizing opium with water in a highspeed blender or by evaporating paregoric to remove alcohol. An entire assay can be performed within 3 hours.
Extraction and Cleanup Procedure for the Gas
Chromatographic Determination of Four Dinitrophenolic Pesticides
Authors: Yip George , Howard Samuel F
Published: February 2020

A gas chromatographic method for the simultaneous determination of four dinitrophenolic herbicides [dinitrocresol (DNOC), dinitrobutylphenol (DNBP), dinitroamylphenol (DNAP), and dinitrocyclohexylphenol (DNOCHP)] in crops has been developed. After a 50 g sample was extracted with chloroform, a 10 g aliquot was concentrated and reacted with diazomethane to form the methyl ether derivatives. The sample was subjected to a two column cleanup step. acid-Celite and Florisil, and the residue was analyzed by GLC with an electron capture detector. Recoveries of fortification levels of 0.1 ppm DNOC and 0.2 ppm DNBP, DNAP, and DNOCHP exceeded 80%. The crops studied included green beans, pole beans, lima beans, peas, apples, and oranges.
Screening Method for Zearalenone., Aflatoxin, and
Ochratoxin
Authors: Eppley R M
Published: February 2020

A rapid and sensitive procedure has been developed for detecting aflatoxin, ochratoxin, and zearalenone. This procedure uses a water-chloroform extraction combined with sequential elution of the mycotoxins from a silica gel column. Applicability to a wide variety of products was demonstrated by analysis of 31 different commodities. Three commodities (cottonseed, green coffee, and capsicum peppers) contained serious interferences for all three toxins.
Preparation of Dehydrated Tomato Powder Samples for
Howard Mold Count
Authors: Krinitz Benjamin
Published: February 2020

Collaborative studies were conducted on two procedures for preparing dehydrated tomato products for analysis by the Howard mold count method, 36.069: Procedure I, a modification of method 36.069, which involves a simple dilution and the determination of per cent solids by refractive index; and Procedure II (FDA procedure), which involves heating and weighing after the calculation of the dilution necessary to give the desired per cent solids. Results indicate that Procedure I is a simple and rapid means of preparing dehydrated tomato powder.
A New Extraction Method for Light Filth in Ground and Granulated Pecans
Authors: Vazquez Alberto Wanous , Gecan John S
Published: February 2020

A method has been developed that gives good filth recoveries and clean, easy to scan, filter papers. This method deviates from method 36.018 by using 60% alcohol-calcium chloride solution for the aqueous phase and light mineral oil as the flotation medium. Acid hydrolysis in the trap flask, together with the low viscosity and desirable surface properties of alcohol, aids in suppressing plant material. The added calcium chloride gives a high enough density to the aqueous phase to permit denser filth elements to float with ease.
Collaborative Study of the Determination of Ethoxyquin in Chick Tissue and Eggs by Fluorescence
Authors: Deren J M Van , Jaworski E G
Published: February 2020

A collaborative study for the analysis of ethoxyquin was repeated with a modified procedure for the preparation of the standard curve, and all standard curves were satisfactory. Ethoxyquin recovery was good in all tissues analyzed: 76% from egg yolks (lowest recovery) and 88% from fat (highest recovery). The fluorescent spectrum for ethoxyquin shows that the secondary filter is quite critical; light scattering from the sample must be controlled to avoid interferences. Although variation in the control samples was caused by both the source of the tissue samples and the secondary filters, values did not exceed the 10% tolerance level established for ethoxyquin in tissue and eggs. It is recommended that this modified method be adopted as official, first action.
Collaborative Study of a Method for Benzo(a)pyrene in Smoked Foods
Authors: Howard John W , Fazio Thomas , White Richard H
Published: February 2020

A collaborative study was conducted on the method for benzo(a)pyrene in smoked foods published in This Journal 49, 611-617 (1966). Samples of fish and ham fortified with benzo(a)pyrene were analyzed by 13 collaborators. Average per cent recoveries at 10 and 4 ppb (μg/kg) levels by 11 collaborators by the ultraviolet method were 99 and 96%, respectively, for the fortified fish samples and 84 and 78%, respectively, for the fortified ham samples. Comparative average recovery values were obtained by 6 collaborators who also determined the compound by fluorescence. Standard deviations for the two determinative techniques ranged from 3.15 to 13.6%. The method is recommended for adoption as official, first action.
Rapid Analysis of Halogenated Organic Insecticides in Aqueous Animal Dips, Using Sodium Biphenyl
Authors: Czech Fred P
Published: February 2020

Pertinent parameters for an analytical method, using sodium biphenyl, are presented for the quantitative estimation of toxaphene, lindane, DDT, methoxychlor, dieldrin, chlordane, ronnel, Ruelene, eoumaphos, trichlorfon, and naled in aqueous dips. The method is applicable to both insecticide emulsion and wettable powder dips.
Differential Spectrometric Determination of Caffeine in Soluble Coffee and in Drug Combinations
Authors: Ferren William P , Shane Norman A
Published: February 2020

A differential spectrophotometric procedure is described for determining caffeine in food and beverage materials and in drug dosage combinations. The method eliminates the necessity for preliminary separations. The procedure was applied to soluble coffee samples and to APC. Recovery of caffeine from soluble coffee was better than 95% ; results compared favorably with the official micro Bailey-Andrew method. Results for APC were not as good; apparently phenacetin is the limiting factor. The method may be more suitable for other drug combinations or for certain types of automated analyses.
Collaborative Study of a Method and Sampling Techniques For Determining Yeast Count in Maple Sirup
Authors: Kissinger J C
Published: February 2020

Techniques for sampling and a method for determining the yeast count in maple sirup, studied collaboratively in 1966, have been revised and again studied collaboratively in 18 laboratories. Statistical analysis of collaborators' results indicated that sirup samples shipped in a frozen condition gave more concordant interlaboratory yeast counts. More homogeneous cell suspensions were obtained by mixing the sirup samples warmed to 80 °F with a nonaerating stirrer. The method is recommended for adoption as official, first action.
Quantitative Analysis of Phenaglycodol
Authors: Snell Robert P
Published: February 2020

A procedure has been developed for the quantitative and qualitative infrared spectrophotometric analysis of phenaglycodol in tablets and capsules. The procedure consists of a liquid-liquid partition of the drug between chloroform and an aqueous alkaline phase. The quantitative measurement is made at about 9.85 μ relative to a carbon disulfide reference, using the baseline technique. Qualitative analysis employs the KBr disk technique. Five collaborators obtained a relative standard deviation of ± 1.88% for a tablet preparation and ± 1.61% for a capsule preparation. It is recommended that the method be adopted as official, first action.
Collaborative Study of a Spiral Vessel Count Method for Estimating Shell in the Chocolate Component of Cocoa and Related Products
Authors: Jackson Manion M
Published: February 2020

Part-I: The spiral vessel count method for estimating pectic acid in cocoa has been modified to replace the saturated borax solution by 4% NaOH, which gives a clearer product to count, and to include a method for preparing the sample dry fat-free and 250 mesh before analyzing, by hand grinding or grinding by two different grinders. Counts have been made on known shell in the chocolate component mixtures. A formula usable in a 1—15% range and standard curves have been prepared for the estimation of shell in the chocolate component. Counts have been taken at 100X and 200x on a 0.2 g/100 ml concentration, and at 200X on a 0.35 g/50 ml concentration; 200X counting of the higher concentration is preferred for 1—15% shell. Cocoas of known pectic acid content were analyzed by the method and per cent shell found by spiral vessel counts compared with per cent pectic acid. These cocoas were also analyzed before being made 250 mesh for comparative purposes. An intralaboratory study was made on two samples. Part-II: A collaborative study for determining per cent shell by the spiral vessel count method was made on four samples of cocoa products by six collaborators; two samples were defatted and ground to 250 mesh, the other two samples were hand-ground. Five collaborators varied less than 1 standard deviation unit from the average on the four subdivisions; one collaborator was just outside the standard deviation on one sample. The precision of the results was within a reasonable range for a microscopic counting procedure, and the method has been recommended for adoption as official, first action.
Determination of Lignin and Cellulose in Acid-Detergent Fiber with Permanganate
Authors: Van Soest P J , Wine R H
Published: February 2020

A newly developed indirect method for lignin, utilizing permanganate, permits the determination of cellulose and insoluble ash in the same sample. The new permanganate lignin method is intended as an alternative procedure to the 72% sulfuric acid method over which it offers definite advantages as well as certain disadvantages. Choice of methods will depend upon the materials analyzed and the purpose for which the values are to be used.
EDTA Titration of Calcium and Magnesium: Determination of Calcium in Canned Vegetables
Authors: Steagall Edward F
Published: February 2020

The method adopted as official, final action last year was studied collaboratively again this year for calcium in canned vegetable products other than canned whole tomatoes. Twenty-six cans each of whole potatoes with calcium declared on the label and sliced potatoes and lima beans without a label declaration for calcium were analyzed by 13 analysts in 12 laboratories. Again the results were easily reproducible, and the agreement between laboratories was good. Because the method gives continuing precision and low standard deviations, it is recommended for adoption as official, final action for pharmaceutical and vitamin-mineral preparations and canned whole tomatoes, and as official, first action for canned potatoes and lima beans.
Collaborative Study of a New Alkaline Phosphatase Assay System for Milk
Authors: Kleyn D H , Lin S H C
Published: February 2020

A new method in which phenolphthalein monophosphate is used as substrate has been developed for determining residual alkaline phosphatase: Upon hydrolysis, phenolphthalein is released and yields a red solution that is compared visually with a standard prepared from the same milk. Seven collaborators made 168 observations that were used in a statistical study of the results. Chi-square calculations and tests of independence indicated that the described method yields results on skim milk, whole milk, and light cream that are as precise and either as accurate or more accurate than those obtained with the Scharer I method. Based on these results, it is recommended that the method be adopted as official, first action.
Collaborative Study of the Determination of Lead Number of Vanilla Extract By Chelometric Titration
Authors: Johnson Arthur R
Published: February 2020

The Wichmann lead number has been used for over 45 years as an index of vanilla constituents in extracts. A rapid method for lead number determination by chelometric titration was reported by Considine in 1959. This method was subjected to intralaboratory and collaborative study. On the basis of these results, the method is rapid and accurate, and it is recommended for adoption as official, first action.
Review and Recommended Changes in the Flame Photometric Method for Determination of Potassium in Fertilizers
Authors: Hambleton Larry G
Published: February 2020

Ammonium oxalate is, historically, the oldest extractant for available potassium in fertilizer. Lower results have been obtained by the flame photometric method, 2.077, than with the other official methods, possibly because of the extractant, ammonium carbonate. It is recommended that the preparation of solution 2.079(a) be changed to indicate ammonium oxalate as the extractant in place of ammonium carbonate.
Isolation and Purification of Metabolites Found in the Urine of Male Rats Fed Aldrin and Dieldrin
Authors: Klein A K , Link J D , Ives N F
Published: February 2020

A procedure for the isolation and purification of aldrin and dieldrin metabolites derived from rat urine is described. The procedure yields enough material of adequate purity to enable the determination of the chemical structure of the metabolites.
Collaborative Study of Recoverable Oil in Citrus Juices by Bromate Titration
Authors: Scott W Clifford
Published: February 2020

Nineteen collaborators conducted single tests on three citrus juices containing abovit 0.005, 0.010, and 0.030% oil. Standard deviations in per cent recoverable oil were 0.0004, 0.0008, and 0.0014, respectively. Each collaborator also titrated in triplicate a 0.035% solution of freshly distilled orange oil in 2-propanol. The average amount found was 0.0345%, with a standard deviation of 0.0007. The method is recommended for adoption as official, first action.
Isothermal Molecular Weight Determination: Apparatus, Procedure, and Study of Effect of Solvent and Standard on Accuracy and Precision
Authors: Scroggins Laverne H , Ogg C L
Published: February 2020

A study was made of the isothermal molecular weight determination; the apparatus constructed and the procedure developed are described. An extensive investigation was carried out to provide reliable guides for the selection of the correct solvents and standard reference compounds to be used in the molecular weight determination. This study produced statistical evidence of the behavior, in five different solvents, of representative compounds from each of the following chemical groups: hydrocarbons, alcohols, ketones, esters, ethers, acids, nitriles, amines, and sulfides. Analysis showed that acetone and ethyl acetate are the best solvents if the composition of the sample is not known. Chloroform proved to be a good solvent except for samples in which hydrogen bonding could occur. n-Heptane was satisfactory for six of the eight types of compounds; benzene war. by far the poorest solvent
Correlation of the Levels of Several Constituents of Commercial Orange Juices
Authors: Coffin D E
Published: February 2020

The amino acid, betaine, polyphenolics, ash, and phosphorus contents, and the titratable acidity of 32 samples of commercial orange juices and reconstituted orange juices were determined. Wide variations in the levels of these constituents were found but there were no significant differences between the juices and the reconstituted juices. Highly significant correlations were established between the levels of the amino acids, betaine, polyphenolics, ash, and phosphorus. The titratable acidity levels failed to show any significant correlation to any of the other constituents. Multiple regression equations were developed to express the interrelationships between some of the components, and correlation coefficients of combined distributions were calculated.