bluuebunny/crossref_metadata_2025 huggingface dataset:
Extraction and Estimation of Polycyclic Aromatic Hydrocarbons in Vegetable Oils
Authors: Howard John W , Turicchi Elizabeth W , White Richard H , Fazio Thomas
Published: February 2020

A method has been developed for isolatingand determining polycyclic aromatic hydrocarbons in refined vegetable oils. The oils are diluted with an aliphatic solvent and the polycyclic compounds are extracted with dimethyl sulfoxide. They are isolated by column and thin layer chromatographic techniques and measured by ultraviolet and spectrofluorometric procedures. Average recoveries of benzo(a)pyrene, dibenz(a,h)- anthracene, benz(a)anthracene, and benzo-(g,h,i)perylene, added to 200 g oil samples at the 2 ppb level, ranged from 71 to 100%. Benzo(a)pyrene and other polycyclic hydrocarbons were isolated in trace quantities from soybean, cottonseed, corn, olive, and peanut oils.
Investigation of Thermionic Detector Response for the Gas Chromatography of P, N, As, and CI Organic Compounds
Authors: Ives N F , Giuffrida Laura
Published: February 2020

Investigations were conducted to determine the degree of specificity and enhanced response of the thermionic detector, using alkali metal salts. The test compounds included the triphenyl derivatives of group V(a) elements. Because of special interest in nitrogen response, several types of nitrogen compounds were included. The effects of varying jet diameter, carrier gas, and other operating parameters were also studied.
Minerals in Feeds by Atomic Absorption Spectrophotometry
Authors: Heckman Mary
Published: February 2020

Seventeen laboratories collaborated in the study of analysis of feeds for calcium, magnesium, zinc, manganese, iron, and copper by atomic absorption spectrophotometry. Six feeds and one mineral mixture were analyzed; both dry ashing and wet digestion were used to prepare samples. Three feeds were in the form of solutions to eliminate sample preparation as a variable. Strontium and lanthanum were added to the feed to eliminate phosphorus interference and results were compared. Results indicate that the method is suitable for calcium and magnesium. Further work is needed on the determination of zinc, manganese, iron, and copper.
Colorimetric Method for Nitrodan in Feeds
Authors: Bloom Donald V
Published: February 2020

A colorimetric method for nitrodan in feeds was studied on 3 feed samples at levels of 0.015-3.90% nitrodan by 7 collaborators. The samples were extracted with dimetliylformamide-ethanol (1 + 1) and measured at 575 m/i after the addition of dilute NaOH. Average recoveries on samples containing 0.0190, 0.0237, and 3.80% nitrodan were 100.3, 98.3, and 101.8%, respectively; coefficients of variation were 3.4, 4.1, and 2.9%. Blank samples gave negligible results. The method is recommended for adoption as official, first action
Determination of Piperazine in Feeds
Authors: Loucks M F , Nauer Leo
Published: February 2020

Collaborative studies were continued on a modification of the p-benzoquinone colorimetric method proposed by Cavett and Heotis for determining piperazine in feeds. Piperazine is extracted from the feed with water and then reacted with a buffered, hot, alcoholic solution of p-benzoquinone to form a colored complex. Absorbance is measured spectrophotometrically at 490 mμ. Control of the several critical factors, including pH of the solution and time and temperature for the reaction, is necessary. Results indicate a standard deviation (<r) of ± 0.012% and a 95% confidence limit ( 2 o-) of ± 0.024% with an average variation of ± 10%. The mean recovery was 97%. It is recommended that the method be adopted as official, first action
Simultaneous Determination of Volatile Acids and Sulfur
Dioxide in Alcoholic Beverages by Microdiffusion
Authors: Owades Joseph L , Dono Joseph M
Published: February 2020

A new technique has been developed for determining both volatile acid and sulfur dioxide in beer, wines, and distilled liquors. The new method avoids the troublesome distillation common to other methods by use of microdiffusion in an especially modified diffusion cell. Small samples are reqviired and many replicates can be performed in one day. Results were in excellent agreement with the AOAC method for wine, and precision was very good
Evaluation of Gas-Liquid Chromatography for the Quantitative Determination of Fusel Oil in Distilled Spirits
Authors: Brunelle Richard L
Published: February 2020

Gas-liquid chromatography (GLC) was compared to the official AOAC method for the quantitative determination of fusel oil in distilled spirits on 12 samples by 12 collaborators. Results indicated that the GLC procedure described is at least as accurate as the official procedure. Analyses of 26 distilled spirits samples showed that the GLC method was sensitive and capable of reproducing fusel oil content in the 0—10 g/100 L range to ± 0.03 g/100 L. It is recommended that collaborative studies be conducted on the GLC determination of fusel oil, and that work be extended to include analysis of other important congeners in distilled spirits such as ethyl acetate, acetaldehyde, and methanol.
Quantitative Determination of Fixed Acids in Wines by Gas-Liquid Chromatographic Separation of Trimethylsilylated Derivatives
Authors: Brunelle Richard L , Schoeneman Robert L , Martin Glenn E
Published: February 2020

A rapid and simple method was developed for gas-liquid chromatographic (GLC) separation of the trimethylsilylated (TMS) derivatives of the fixed acids present in wine. Acids were precipitated as lead salts to eliminate sugar interference. The TMS derivatives were completely separated on a 6' X 14" o.d. glass column of 3.8% SE-30 on Diatoport S (silanized support) and were measured by reacting the dried lead salts with trimethylchlorosilane and hexamethyldisilazanc in the presence of pyridine. This method permits the simultaneous determination in wine of several acids, such as succinic, malic, tartaric, and citric acids in ca 4 hours. Several other derivatives were observed in the chroniatograms but were not identified
Detoxification of Anatoxin in Peanut Meal by Hydrogen Peroxide
Authors: Sreenivasamurthy V , Parpia H A B , Srikanta S , Murti A Shankar
Published: February 2020

A new approach to destroy aflatoxin in toxic peanut meal has been described. It involves heat treatment of the meal at 80°C for ½ hour with hydrogen peroxide at a pH of 9.5. The destruction of aflatoxin is confirmed by biological tests, using ducklings and duck embryos.
1966 Collaborative Study on the Determination of Iron in
Fertilizer by Dichromate Titration
Authors: Ingram William J
Published: February 2020

Iron can be determined by direct dichromate titration or otber metbods after perchloric oxidation. Perchloric oxidation does not destroy all organic material and gives acceptable results. High values of P205, K20, and NH4N03 do not interfere. Average collaborative values for iron by dichromate titration are: 12% iron, found 12.08%; 2.65% organic fertilizer, found 2.58%; 2.50% iron (with 30% P2O5 ), found 2.49%; 1.0% iron (57.5% NH4- NO3), found 1.06%; 0.18% iron, found 0.19%. It is recommended that the dichromate titration method be adopted as official, first action, and that furtber study be made on methods of sample preparation
Analytical Methodology of Oxytetracycline in Feed
Authors: Billman D C , Clark II
Published: February 2020

Two experiments were conducted to evaluate modifications of the AOAC method for determining oxytetracycline (OTC) in feed and 4 methods of preparing compensating curves for this modified method. The modifications involved use of a 20 g sample, extraction in extraction flask, and filtration of the assay solution. Compensating curves were prepared from blank feed extracts and extracts of test blends in which OTC was inactivated by either boiling in sodium hypochlorite, passing through adsorption columns, or refluxing 18 hours. At levels of 25 g OTC/ton and higher, the modified AOAC method gave 100% recovery with a coefficient of variation of 8.1%. At 10 g/ton, 92% was recovered with a coefficient of variation of 11.0%. Compensating curves showed 58—91% recovery at 10 g OTC/ton with an average coefficient of variation of 21.8%. The method will be submitted to collaborative study.
Silver Nitrate and Thiocyanate Standard Solutions
Authors: Corrigan Edward D
Published: February 2020

Official Methods of Analysis was reviewed for these two standard solutions to eliminate all unnecessary duplication of instructions in preparation and standardization
A Comparative Study of Methods for the Determination of
Moisture in Cheese
Authors: Strange Theron E
Published: February 2020

Eleven types of cheese were analyzed for moisture by the official AOAC method and by a method proposed by the International Dairy Federation (IDF). Some cheeses were also analyzed by the AOAC rapid screening method and by a proposed distillation method. The IDF method requires mixing 3 g cheese with about 20 g dried and weighed sand, then drying at 105°C for 4 hours. In the proposed distillation method, moisture is distilled from cheese (9—15 g) with xylene and n-amyl alcohol (2 + 1) into a Bidwell-Sterling type of receiver. Comparative results show that the official method is not applicable to cheeses with a relatively high content of volatile compounds, such as Bleu cheese; that the AOAC rapid method and the distillation method give results in about 12 hours that agree well with the official method for other types of cheese; and that the IDF method gives results about 0.2 % lower than those by the official method (actual difference). Preliminary studies on the Karl Fischer titration procedure and a gas-liquid chromatography procedure indicate that these procedures may be suitable as basic reference methods
Additional Cleanup of Samples on GLC Column for
TLC Determination of Pesticide Residues
Authors: Hartman Kenneth T
Published: February 2020

Gas-liquid chromatography (GLC) following conventional isolation procedures has been used to clean up pesticide residues for confirmation by thin layer chromatography (TLC). This procedure is more rapid and efficient than present cleanup procedures and permits the determination of pesticide residues that do not survive these rigorous acid or alkali treatments. The method also permits TLC confirmation of pesticide residues that have similar Rf values but different GLC retention times. Recoveries ranged from 85 to 105% for 25 of 28 pesticides tested
Spectrophotometric Determination of Strychnine in Brucine Sulfate (or the Alkaloid)
Authors: Rehn Burton W
Published: February 2020

A method is described for the quantitative determination of strychnine in brucine or brucine sulfate. In the method, brucine is nitrated and strychnine is extracted with chloroform (as in National Formulary IX). The chloroform is then evaporated and strychnine is determined spectrophotometrically by dissolving the residue in O.1 N H2SO4 and measuring absorbances at 254 and 275.5 mμ. The difference between these absorbances, compared with similar differences at these wavelengths for standard strychnine solutions, is a measure of the strychnine content. Eleven tests over a range from 1 to 12.5% strychnine in brucine gave results with a standard deviation of less than 0.03%
Collaborative Study of a Fluorometric and Thin Layer Chromatographic Determination of Aminacrine and Its Salts in Drug Preparations
Authors: Roberts Laura A
Published: February 2020

Eight collaborators studied a fluoromelric and thin layer chromatographic method for aminacrine and its salts in powder and cream drug preparations. Recovery of aminacrine.HCI by fluorometer in both preparations averaged 100% for powder and 102% for cream. The mean concentration of aminacrine.HCI found in the powder was 0.108% with a standard deviation of ± 0.001%. The mean concentration of aminacrine found in the cream was 0.191% with a standard deviation of ± 0.003%. Seven of the 8 collaborators successfully used thin layer chromatography to identify the aminacrine in both sample forms supplied. The assay method for aminacrine and its salts in drug preparations is recommended for adoption as official, first action
An Improved Analytical Procedure for the Determination of Xanthophyll
Authors: Kohler G O , Knowles R E , Livingston A L
Published: February 2020

A modified procedure is described for the determination of carotene and xanthophyll in fresh and dehydrated alfalfa and grass meal. In this method, both carotene and total xanthophyll can be measured from a single extract. The carotenoids in dehydrated alfalfa or grass meal are extracted by overnight soaking in hexane-acetone (7:3) ; those in the fresh plant material are rapidly extracted by blending with acetone. A cold saponification method eliminates possible chlorophyll contamination of the xanthophyll fraction during chromatography. Data on the precision of the modified methods are presented
Detection and Identification of Salmonella from Dried Whole Egg, Dried Egg Yolk, and Dried Egg White: Report of a Collaborative Study
Authors: Poelma Paul L
Published: February 2020

In this method 25 g of sample is preenriched in lactose broth, incubated, subcultured in selenite cystine broth and tetrathionate broth, incubated, and streaked on selective plates of brillant green agar, Salmonella Shigella agar, and bismuth sulfite agar. After incubation of the selective plates, suspicious colonies are transferred to triple sugar iron agar slants and incubated. Cultures arc identified as Salmonella or not Salmonella by biochemical and serological tests. Eleven of the 13 collaborators reported correct results. Evaluation of the results indicates that the method does detect and identify Salmonella from positive samples with a level of about 35 Salmonella cells/25 g of sample. The method is recommended for adoption as official, first action.
Separation of Manganese, Cobalt, Copper, Zinc, and Magnesium By Using an Anion Exchange Resin
Authors: Breatjlt Eugene A
Published: February 2020

The metals Mn, Mg, Co, Cu, and Zn were separated by using an anion exchange resin column and progressively less concentrated IIC1 solution as eluting agent. The position of Mg on an anion exchange resin, not previously reported in the literature, was determined. It has been shown that by using two different ion exchange resin columns, simple hydrochloric acid solutions as eluants, and polarographic or flame photometric determinations, 12 metals can be separately estimated in an aqueous solution containing about 100 /μg of each. It is recommended that the study of ion exchange resin separation of metals found in plants be continued.
Flame Photometric Determination Of Calcium In Food, Using A Reversed Oxyacetylene Flame, A Radiation Buffer, And An Acid Mixture
Authors: Lehmann Joanna , Zook Elizabeth Gates
Published: February 2020

A flame photometric method, utilizing a reversed oxyacetylene flame in conjunction with a Beckman Du spectrophotometer, equipped with a 1P28 photomultiplier tube and a Beckman acetylene burner, is described. using this simple equipment modification, a mixed radiation buffer, and HCI-H3PO4 mixture, interferences from Na, K, P, Mg, Fe, S, and Al over the concentration ranges usually found in relation to calcium content of foods were controlled. Recoveries of calcium added to foods prior to ashing averaged 100 ± 1.38%. No significant differences in calcium values were found for four fruits, two vegetables, and two food composites whether determined by this flame procedure or by the official AOAC micropermanganate titration procedure.
Determination of Carotene in Fresh Forages and Silages Following Freeze-Drying and Grinding
Authors: Gillingham J T
Published: February 2020

The carotene content of fresh forages and silages has been analyzed by two methods: AOAC method 39.015(a) and the Bickoff et al. method modified to include freeze-drying and grinding of the sample and chromatographing only an aliquot after extraction. Data on orchardgrass, fescue, clover-grass mixtures, and silage samples indicated that the method described is accurate and reproducible. The average variation is ± 8μg/g and identical values in duplicate determinations are recorded in 16 out of 34 values.
Gas Chromatographic Determination of Butylated Hydroxyanisole and Butylated Hydroxytoluene in Breakfast Cereals
Authors: Takahashi David M
Published: February 2020

The gas chromatographic method for BHA and BHT in rice and corn ready-to-eat cereals was revised to include CS2 elution of the antioxidants and gas-liquid chromatography, using a hydrogen flame ionization detection system for the determination. Different gas chromatographic columns were found to be more suitable: 5% Apiezon L on 80/100 mesh Gas Chrom Q (4' column), and 10% QF—1 silicone oil on 80/100 mesh Gas Chrom Q (6' column). The elution order of the antioxidants is reversed on the two columns. 3,5-Di-tertbutyl- 4-hydroxyanisole is used as the internal standard. Recoveries of the two antioxidants added at 5, 10, 25, and 50 ppm levels, were 96—106% with the QF-1 column and 96—104% with the Apiezon L column. Studies on this method will continue.
Screening Method for the Detection of Chlorinated Hydrocarbon Pesticide Residues in the Fat of Milk, Cheese, and Butter
Authors: Moubry R P , Myrdal G R , Jensen H P
Published: February 2020

A screening method has been developed for detecting chlorinated hydrocarbons in dairy products; a detergent extraction procedure is used for milk and a continuous extraction procedure is used for cheese. A fat-Florisil sample is added to a column of partially deactivated Florisil; the pesticide residues are eluted from the column with liexane: ether, while the fat is retained on the column. The residues are identified by electron capture GLC, using a mixed bed DC-200/QF-1 column.
Study of Modifications of the Mills Procedure for Chlorinated Pesticides in Dairy Products
Authors: Furman William B , Fehringer Norbert V
Published: February 2020

The effects of butterfat upon the partition coefficients of lindane, heptachlor, aldrin, heptachlor epoxide, dieldrin, endrin, and p,p'-DDT in the acetonitrile-petroleum ether solvent system are reported. The theoretical recoveries for these pesticides are presented and are compared with recoveries calculated for certain variations in the extraction method and with actual working recoveries. The distribution of these pesticides in the acetonitrile-water-petroleum ether solvent system and the effect of NaCl are discussed. Several revisions of the method are proposed to increase the recovery of chlorinated pesticides from dairy products.
Determination of Linuron and Its Known and/or Suspected Metabolites in Crop Materials
Authors: Katz Stanley E
Published: February 2020

Linuron and its known and/or suspected metabolites are extracted from crops with acetone. The acetone is evaporated, and the aqueous residue containing precipitated plant materials and linuron and metabolites is extracted several times with hexane to remove linuron and any 3,4-dichloroaniline, a metabolite. The 3,4-dichloroaniline is separated from the linuron by HC1 extraction. Other possible metabolites, 3-(3,4- dichlorophenyl)-l-methoxy urea, 3-(3,4-dichlorophenyl)- l-methyl urea, and 3-(3,4-dichlorophenyl) urea, remain in the aqueous phase which is made basic with ammonium hydroxide. These metabolites are extracted into hexane and identified by thin layer chromatography. Linuron and metabolites other than 3,4-dichloroaniline can be determined colorimetrically after acid hydrolysis to the aniline, followed by a diazotization reaction and coupling with iV-(l-naphthyl) ethylenediamine. Levels as low as 0.02 ppm linuron can be detected. Recoveries of 98.9% were found. Bound linuron can be determined by alkaline hydrolysis or by enzymatic digestion of crop material which frees the undegraded bound linuron
Determination of Biphenyl in Citrus Fruits by Thin Layer Chromatography and Ultraviolet Spectrophotometry
Authors: Corneliussen Paul E
Published: February 2020

A rapid method for determining biphenyl in citrus fruits has been developed and was studied collaboratively. Biphenyl is separated from fruit tissue by steam liquidliquid extraction. The ra-heptane extract is subjected to preparative thin layer chromatography (TLC) on plates coated with silica gel containing phosphors for ready visibility of the biphenyl spots under UV light. The spots are removed from the plate and extracted with alcohol for spectrophotometric measurement at 248 mμ. The TLC cleanup adds specificity to the method; o-phenylphenol, if present, does not interfere and crop blanks are insignificant. The average of 36 recoveries (12 each at abovit 100, 50, and 10 ppm) was 96.7% with a mean deviation of 10.7%. It is recommended that the method be adopted as official, first action.
Determination of Starch and Soluble Carbohydrates. I. Development of Method for Grains, Stock Feeds, Cereal Foods, Fruits, and Vegetables
Authors: Friedemann Theodore E , Witt Norman F , Neighbors Bonnie W
Published: February 2020

Starch is determined in samples containing not > 400 rag available carbohydrate by the following procedure: The fat is extracted with isopropanol, the solution is diluted to 70% alcohol concentration, NaCl and Celite are added, and the soluble sugars are extracted. Starch is hydrolyzed with Rhozyme-S, the solution is clarified with Zn(OH)2 , and the reducing sugar content is determined by reduction of potassium ferricyanide. Maltose and other soluble saccharides are present in the 70% isopropanol extract. The solubility of enzymatically hydrolyzable oligosaccharides, minus maltose, of three commercial soluble starches and three commercial dextrins in 0 - 7 0% isopropanol-1 % NaCl was determined. In 70% isopropanol, the respective solubilities of the hydrolyzable oligosaccharides were as follows: starches—0.4, 3.4, and 0.5%; dextrins—4.9, 3.3, and 6.1%. In 40% isopropanol, the respective solubilities were 12.7, 9.8, and 62.3% of the starches and 92.3, 88.2, and 89.4% of the dextrins. Although the soluble starches and dextrins were water-soluble, they contained up to 9.5% (6.5% average) oligosaccharides that were not hydrolyzable by enzyme but were hydrolyzable by l.OA' HCl. Use of 40% isopropanol is recommended for extraction of oligosaccharides of low DP (dextrins, maltose, etc.) and determination of the insoluble oligosaccharides of relatively high DP. Retrogradation of starch and its prevention during the analysis is discussed. Starch and soluble sugars were determined in 21 samples of grains and breakfast cereals and in 12 samples of roughages.
Analysis of Limestone
Authors: Rexroad Paul R
Published: February 2020

Results from six limestone samples show that 15—20% more of the sample passes through a No. 40 sieve by wet sieving than by dry sieving when the agglomerates are not broken up for dry sieving. Excessive clay found in the additional material represents 1—3% of the sample. It is recommended that study be continued on method 1.002 with emphasis on breaking up the agglomerates or that a wet sieving method be adopted as official, first action.
Direct Fluorescent Detection of Organothiophosphorus Pesticides and Some of Their Sulfur-containing Breakdown Products After Thin Layer Chromatography
Authors: Ragab Mohamed Tawfik H
Published: February 2020

A rapid, simple, convenient, and widely applicable method for the direct fluorescent detection of organothiophosphorus pesticides and some postulated breakdown products of these compounds is presented. The coinpounds were spotted on thin layer chromatographic sheets, developed in ethyl acetate :nhexane, and made visible by exposure to bromine vapor followed by spraying with ferric chloride and 2-(o-hydroxy phenyl) benzoxazole. Of the 47 compounds tested, 32 compounds produced fluorescent blue spots vinder longwave ultraviolet light; these consisted of 25 organothiophosphorus pesticides, 5 sulfur-containing breakdown products, and phosphoric and hypophosphorous acids. A superimposed Congo red spray destroyed the fluorescence and resulted in dark blue spots against a red backgrovind. The sensitivity of this method is in the range of 0.2 to 5.0 μg, depending on the specific compound.
Fly Identification by the Morphology of the Head and Head
Appendages
Authors: Carson N Aubrey , Martinez Edmund F
Published: February 2020

Ten fly species are identified by the morphology of the head and head appendages. Detailed descriptions and numerous drawings are used to identify the fly heads, antennal segments, and mouthparts. Fragment identification provides a basis for species identification.
Determination of Bitterness of Olives
Authors: Cohen S , Lifshitz A , Samish Z
Published: February 2020

An objective analytical method for the estimation of bitterness of fresh and fermented olives has been developed. Results of the bitterness estimation by the proposed method were in good agreement with organoleptic tests performed concomitantly. The method is based on the extraction with acetone of a bitter constituent from the olive, adsorption of possible interfering materials on gelatin and alumina, and spectrophotometric determination of the resulting bitter solution.
Temperature-Programmed Gas Chromatography of 20 Phosphorus-Containing Insecticides on 4 Different Columns and Its Application to the Analysis of Milk and Corn Silage
Authors: Bowman M C , Beroza Morton
Published: February 2020

Relative retention times and conditions for the gas chromatography of 20 phosphorus- containing insecticides on 4 column packings, DC-200, QF-1, DC-710, and stabilized DEGS, have been determined. With temperature programming, it is possible to analyze compounds of widely differing volatilities in a single run with good sensitivity and a large saving in time. Compounds were detected with the flame photometric detector of Brody and Chaney in both the phosphorus- and sulfur-sensing modes and were identified in milk and corn silage at levels as low as 0.01 ppm. Recoveries of the insecticides from corn silage exceeded 90% and more often were better than 95%; those from milk were at least 80% and usually were above 90%. The gas chromatography in a single multicomponent analysis required from 12 to 28 minutes. The procedure shows promise for identification or multicomponent analysis of phosphorus- and sulfur-containing pesticides as well as for the monitoring of foodstuffs and forage for these pesticides
Gravimetric Procedure for the Quantitation and Identification of Polysorbate 80 in Pickle Products
Authors: Barcklow Patricia
Published: February 2020

A qualitative and quantitative gravimetric procedure for Polysorbate 80 in pickle products involves acid hydrolysis of the comminuted sample, saponification, extraction of the glycol portion of the molecule with chloroform, and removal of interfering fatty acids with petroleum ether. The glycol is finally precipitated with silicotungstic acid, determined gravimetrically, and identified by infrared spectroscopy. Recoveries from commercially prepared pickle relish and dill pickles containing 0.01 to 0.02% Polysorbate 80 ranged from 80 to 98.5%
Rapid Ammonium Citrate Extraction Method for
Determination of Available Phosphorus
Authors: Guerrant Gordon O , Hunter J D , Mcbride C H
Published: February 2020

Available phosphorus has been determined in fertilizers by a quick extraction method useful for screening or quality control purposes. Samples were extracted in a Gooch crucible with a jet of 65 °C neutral ammonium citrate in 10—20 mill. A single direct determination of available phosphorus was made by the alkalimetric quimociac method, modified for speed and for use in high citrate concentrations. The results compare favorably in accviracy to the gravimetric quimociac results reported on 20 Magruder check fertilizer samples
Excretion of Cyclamate in the Rat
Authors: Sonders Robert C , Wiegand R G , Netwal J C
Published: February 2020

The utility of the gas chromatographic procedure for cyclamate has been confirmed. 14C-cyclamate was traced through the procedure to determine distribution at each step. The recovery of dietary cyclamate in excreta of the rat was found to be complete, in contrast to an earlier report Complete recovery was obtained by gas chromatographic analysis of fed cyclamate as well as by isotope recovery of a trace dose of i ^C-cyclamate. Sifting of cyclamate to the bottom of the food containers could account for the low excretion data previously reported
Assay of Rauwolfia serpentina
Authors: Kunze Frieda M , Barkan Susan , Banes Daniel
Published: February 2020

The lengthy NF XII assay for Rauwolfia serpentina products can be considerably shortened by faster extraction procedures. In the proposed method, Rauwolfia root is homogenized for 10 min with alcoholsulfuric acid, and the evaporation of solvents in the chromogenic step has been eliminated. This modification requires only 3 hr and results are in good agreement with the official method. A collaborative study is planned.
Mass Spectral Identification of Some Hallucinogenic Drugs
Authors: Bellman Sander W
Published: February 2020

A general method is given for the mass spectral identification of some hallucinogenic drugs. The fragmentation patterns observed in the spectra are discussed. Three groups of hallucinogens have been studied: lysergic acid amides, methoxy substituted phenylalkylamines, and tryptamine derivatives. Similarities in the fragmentation patterns of the members of each group are observed. The fragmentation patterns described can be used to identify hallucinogenic drugs even in the presence of low molecular-weight impurities.
Determination of Isoproterenol in Deteriorated Inhalations
and Injections
Authors: Welsh Llewellyn H , Sammul Oscar R
Published: February 2020

Isoproterenol forms an ether-soluble ion pair with di-(2-ethylhexyI) phosphoric acid, while the sulfonic acid produced by the reaction with bisulfite antioxidant in aqueous dosage forms does not. This fact and the use of partition chromatography form the basis of a convenient method for determining isoproterenol in inhalation and injection preparations. Of 22 such commercial solutions, ranging in age from 4 to 28 months, analyzed by this method, 14 showed isoproterenol losses of 10 to 62%. Standard recovery experiments indicate the method should be useful in the quantitative determination of a number of drugs structurally related to isoproterenol
Selection of Partition Chromatographic Systems from
Distribution Diagrams: Determination of Dextromethorphan in Cough Sirups
Authors: Doyle Thomas D , Levine Joseph
Published: February 2020

Ionization and extraction constants for dextromethorphan and 14 other alkoids are given. By constructing the logarithmic distribution diagrams for mixtures of these compounds, Celite partition chromatographic systems can easily be selected for their separation; both free base and ionpair extraction provide useful systems. A general procedure for the isolation of dextromethorphan from any of those alkoids with which it is currently formulated is presented; the results of analyses of standard samples and of commercial sirups are given. Some other separations do not appear to be feasible. However, the distribution diagrams clearly show the reasons for this fact
Automated Spectrophotometric Method for Nitrogen in
Fertilizers
Authors: Gehrke Charles W , Kaiser Floyd E , Ussary James P
Published: February 2020

An automated spectrophotometric method utilizing the Technicon Autoanalyzer has been developed to determine nitrogen in fertilizer digestates in the range from 5 to 15 ppm nitrogen at a rate of 40 analyses per hour. NH4 is determined by reacting it with phenol and hypochlorite in an alkaline medium to form a blue compound closely related to indole phenol. Optimum reagent concentrations for the colored reaction were determined, and several ions were investigated to determine if they interfere with the reaction. Comparison of results obtained by the automated method and the comprehensive nitrogen method in primary standard grade NH4SO4 and KN03, Magruder check samples, and several commercial fertilizers show that the automated method is accurate and precise. The automated method results in considerable saving of analytical time, especially in laboratories analyzing large numbers of samples
Variation of Florisil Activity: Simple Method for
Measuring Adsorbent Capacity and Its Use in Standardizing Florisil Columns
Authors: Mills Paul A
Published: February 2020

Sodium sulfate content was found to be the principal cause of variation of adsorbancy between batches of Florisil. A rapid method was developed for determining the adsorptive capacity of Florisil based on the absorption of lauric acid from hexane solution. An excess of lauric acid is used and the amount not adsorbed is measured by alkali titration. Lauric acid adsorbed (mg/g Florisil) is used to calculate, by simple proportion, equivalent quantities of Florisil from batches having different adsorptive capacities.
Distribution of Radioactivity in Milk Resulting from
Oral Administration of 14C—Labeled Carbarl
Authors: Baron R L , Palmer Nancy J , Ross R , Doherty J , Jacobson W C
Published: February 2020

Carbonyl-1 'C-labeled carbaryl administered orally to a lactating cow at a dose of 3.05 mg/kg resulted in the appearance of radiolabeled materials in milk. About 1% of the administered dose of 14C was recovered in the whole milk with a maximum concentration of 2.6 ppm carbaryl equivalents found in 9 hr. Radiometric assay of the milk fat showed a maximum level of 4.1 ppm carbaryl equivalents. Analysis of the skim milk by thin layer chromatographic assay failed to show the presence of carbaryl
Estimation of Chlorinated Pesticide Residues in Animal and
Vegetable Oils
Authors: Singh J , Lanthier J D
Published: February 2020

A procedure for the determination of chlorinated pesticide residues in cottonseed oil, hydrogenated marine oil, seal oil, butter oil, and processed beef tallow is described. The oil is spread in the form of a thin film over a large surface area provided by Celite 545. The pesticides are extracted from the oil-coated Celite with 80% aqueous acetonitrile, partitioned into Skellysolve F, and cleaned up on a basic alumina (activity III) column. Gas chromatography with an electron capture detector is used for qualitative and quantitative estimations. The average recovery of six commonly used chlorinated pesticides (aldrin, dieldrin, heptachlor, heptachlor epoxide, lindane, and p,p'-DDT) at levels of 0.1 and 0.25 ppm ranged from 82 to 106%.
Structure of Klein's Metabolites of Aldrin and of Dieldrin
Authors: Damico Joseph N , Chen Jo-Yun T , Costello Catherine E , Haenni Edward O
Published: February 2020

Certain predominant unknown metabolites of aldrin and of dieldrin, previously reported in the urine of rats on diets containing these pesticides, have been characterized by mass, infrared, and Raman spectrometric examination. By interpretation of all the evidence adduced, the structure of the isomeric metabolites of aldrin and dieldrin. respectively, could be postulated. The metabolites appear to be almost identical, the minor spectrometric differences being attributed to possible alternative exo- or endo-orientations of an epoxide ring.
Automatic Recording of the Molecular Sieve Effects of Sephadex, Using Liquid Chromatograph with the Thermal Detector
Authors: Nagasawa Kakuma
Published: February 2020

Ethylene glycol and its oligomers can be separated by chromatography on Sephadex, using a thermionic detector. The fractionation is then recorded automatically. The separation with the thermal detector is reproducible and has a sensitivity of 0.01 to O.lilf ethylene glycol.
Mass Spectra of Some Carbamates and Related Ureas. II
Authors: Benson W R , Damico J N
Published: February 2020

Mass spectral data for fourteen carbamates, live dithiocarbamates, one thiocarbamate, and eight phenylureas are given with some interpretations. Among the compounds examined were some sulfur-containing aliphatic oxime carbamates; these lost the sulfur moieties more easily than the methyl isocyanate moiety. In the aryl IV-methylcarbamate series, the CH3NCO moiety appears to be lost most easily, as it is in pyrolysis. When l-(2-chlorophenyI)-3- methylurea is fragmented, unexpectedly the [HNC0]+ ion is found in high relative abundance. However, the remaining ureas undergo fragmentation in a manner similar to their related carbamates. Although the two ethylene bisdithiocarbamates give essentially identical fragmentation patterns, the spectra of the other four thio- and dithiocarbamates show sufficient differences so that they may be distinguished from one another.
Determination of Shell in Crabmeat, Clams, and Oysters
Authors: Osman Evelyn M
Published: February 2020

The method for the determination of shell in crabmeat has been expanded to include clams and oysters. Collaborative results were good, and the method is recommended for adoption as official, first action.
Rapid Method for the Extraction of Light Filth from Paprika
Authors: Thrasher Joel J , Brickey Paris M
Published: February 2020

A rapid extraction method has been developed for the separation of light filth from paprika; in the method, paprika is defatted with a surfactant, wet sieved, and floated with n-heptane from 60 % alcohol and Tween 80-Versene mixture. Collaborative results by the method gave 8.7 and 16.1% increased recovery of insect fragments and rodent hairs, respectively. The method is recommended for adoption as official, first action.
Updating Analytical Constants For Egg Content of Food
Authors: Wojtowicz Pamela F , Stauffer Leonard J
Published: February 2020

Further studies on the sterol content of durum flour and semolina were conducted by the digitonin method, 13.131. The vahies obtained for durum flour and semolina are recommended for use in the general formula for estimating the egg content of noodles.
Fluorodensitometric Measurement of Aflatoxin Thin Layer Chromatograms
Authors: Beckwith A C , Stoloff Leonard
Published: February 2020

The precision limit of visual comparison procedures used in aflatoxin assay methods can be no better than ± 2 0 % for a single observation and, under operating conditions, it is probably close to ± 2 8 % . Fluorodensitometric procedures described in the literature can improve this precision to ± 9% for the average of multiple observations. A possible source of inaccuracy in the published densitometric procedures is pointed out and a method using internal standards to avoid the inaccuracy is presented. Tested with spiked extracts of "clean" peanut butter, the procedure gave an average 101 ± 3% recovery of added aflatoxin B1 and 89 ± 6% recovery of aflatoxin B2 with a precision for individual assays equal to the precisions reported for the other procedures. The major source of error was shown by elimination to reside in the thin layer chromatography and aflatoxin instability.
Improved Method for Determination of Extractable Color in Capsicum Spices
Authors: Rosebrook D D , Bolze C C , barney J E
Published: February 2020

The variables that affect the determination of extractable color in paprika and other capsicums by the official ASTA method were examined in a preliminary study. As a result, an improved method was devised and tested in a statistical program involving four types of paprika, four extraction times, two sample weights, and two filtration techniques. The improved method permits analysis in 4 hours.
Estimation of Residues of Uracil Herbicides by Gas Chromatography After Evaporative Co-distillation
Authors: Gutenmann W H , Lisk D J
Published: February 2020

A gas chromatographic method has been developed for estimation of residues of uracil herbicides. The method involves sample extraction by blending with ethyl acetate, isolation of the herbicides by evaporative co-distillation, and electron affinity detection following chromatography on a Ucon Polar column. The procedure has been used to recover 0.04—0.4 ppm of bromacil added to soil and 0.5—1.0 ppm of terbacil added to alfalfa.
Isolation and Concentration of Traces of Lead with Strontium Sulfate
Authors: Flann Bruce C , Bartlet John C
Published: February 2020

Lead in trace quantities is co-precipitated as the sulfate with milligram quantities of strontium carrier, using dilute sulfuric acid. The precipitate is separated from the excess sulfate by centrifuging and is then converted to the carbonate by agitation with ammonium carbonate solution. The carbonate precipitate is separated, dissolved in a slight excess of hydrochloric acid, and then freed of carbon dioxide. The solution, buffered to a pH of 8.8, is immediately extracted with a solution of dithizone in chloroform, and the lead is determined spectrophotometrically. Recoveries are approximately 100% and moderate quantities of the following ions do not interfere: Cd; Co (II) ; Cu (II) ; Fe (II); Fe (II); Mn (II); Hg (II) ; Ni (II) ; Ag (I) ; and Zn. Cyanide buffer is not required, all the chemistry is done in the same centrifuge tube, and many samples can be analyzed simultaneously, using readily available equipment
Identification of Commercially Used Fish Found in the Pacific by Disk Electrophoresis
Authors: Chu Rod
Published: February 2020

Identification of fish by disk electrophoresis was studied. Five fish of the sole family yielded electrophoretograms sufficiently dissimilar to identify them properly. The members of the rock family, with the exception of two of the eight species investigated, could not be distinguished on the basis of their electrophoretograms. However, a fish could be characterized as being either a rock or a sole. Two other species had characteristic profiles. These results indicate that the disk electrophoresis method can be utilized with limited success for the identification of these fish.
Experimental Sampling of Bulk Feed: Comparison of Virginia Feed Trier and Missouri D Tube
Authors: Spruill C Kermit
Published: February 2020

Trials of bulk sampling of feeds were made with two types of samplers, the Virginia feed trier and the Missouri D tube. Twenty-five products were sampled. Results of analyses agreed well, but because of some differences, the study will be continued.
Colorimetric Determination of Nitrates and Nitrites in Feeds
Authors: Schall E D , Hatcher D W
Published: February 2020

A method for determining nitrates and nitrites in feeds was developed and studied collaboratively. The partially clarified sample solution was passed over a cadmium column to reduce the nitrate to nitrite; nitrite was then determined colorimetrically. The method was applicable to microgram levels. Collaborative results were good, and the method is recommended for adoption as official, first action.
Uric Acid as an Index of Insect Infestation in Flour
Authors: Sen N P
Published: February 2020

The sensitivity of the enzymatic-ultraviolet method for determining uric acid in flour has been improved by modifying the method of extraction. Uric acid is extracted from flour with methanol containing LiOH, and after evaporation of methanol, viric acid in the extract is measured enzymically. Uric acid can now be detected at a level of 50—60 μg/100 g of flour. This method has been used to determine the amount of uric acid and the rate of its excretion by larvae, pupae, and adults of the insect Tribolium castaneum Herbst. Although the rate of excretion of uric acid/mg body weight for the larvae was higher than that of adults, the larvae were found to contain less uric acid than the adults and the pupae in their whole-body homogenates. Preliminary results indicate good correlation between the insect fragment counts and uric acid levels in flours manufactured from naturally infested wheat.
Determination of Cesium-137 and Related Sampling Problems of Dairy Cattle Feeds, 1962-1967
Authors: Ward G M , Johnson J E , Whelan D L
Published: February 2020

Samples of feeds fed to dairy cattle on the university farm were analyzed from 1962 to 1967 for fallout 137Cs by means of gamma-ray spectrometry. Maximum levels were observed in first-cutting alfalfa hay in 1963 (3600 pc/kg).Second and third cuttings each year were lower by factors of two to six. Levels declined each year after 1963 to barely detectable levels in mid-1967. Pasture forage or green-cut alfalfa contained concentrations of 137Cs similar to hay with the same seasonal and yearly patterns. Corn silage contained levels similar to later cuttings of hay. Grain mixes contained levels which were lower than forages by a factor of 10 in 1962-1963 but approached equal levels in subsequent years. The results indicated that sampling was much more important than radiation counting in explaining variation between sampling. The levels of 137Cs found in the feeds was readily explained in terms of observed patterns of fallout during this period.
Collaborative Study of the Thermistor Cryoscopic Method for the Determination of the Freezing Point Value of Milk
Authors: Henningson R W
Published: February 2020

Data from 19 collaborators for two sample pairs were used to estimate the precision and systematic error of the thermistor cryoscopic method for determining the freezing point value of milk. Precision was greater for the milks (0.0015°) than for the standards (0.004°). The systematic error was estimated to be 0.0033°. The standard deviation for interlaboratory individual determinations was estimated to be 0.0049°.
Determination of Choline in Feeds
Authors: Roberts Talmadge , Fritz James C
Published: February 2020

The amount of choline in feedstuffs and mixed diets was determined by chemical, microbiological, and biological methods and the results were compared. The results of the chemical assay, based on the Reineckate method, varied according to the extraction procedure. The results of the microbiological method, using the Neurospora crassa mutant, seemed high, and the results of the biological chick assay were closer to the calculated values. Calculated or published values for choline chloride in a chick starter feed, degermed yellow corn meal, dehulled soybean meal, dried brewers yeast, and dried torula yeast were 1.93, 0.44, 2.86, 3.63, and 2.75 mg/g, respectively. Chemical results by the rapid Reineckate method were 1.66—2.10, 0.40-0.48, 1.78-2.14, 0.38, and 0.49-0.60 mg/g, respectively. Results were 2.00, 0.45, 3.40, 4.97, and 4.50 mg/g, respectively, by the longer Engel method. The microbiological and biological assay results were 2.28, 0.65, 4.01, 4.78, and 7.60; and 2.07, 0.55, 2.93, 4.69, and 5.98 mg/g, respectively. Further study is recommended.
Recommended Changes in the Method for Detection and Identification of Salmonella in Egg Products
Authors: Poelma Paul L
Published: February 2020

Changes are recommended in the AOAC method for detection and identification of salmonellae in egg products to prevent the analyst from discarding atypical cultures; certain TSI agar cultures are tested with lysine iron agar before discarding them as not salmonellae. These changes were necessary since several investigators have isolated lactose-fermenting salmonellae from clinical cases and foods, and sucrose-fermenting salmonellae have also been reported.
Determination of Hydroxybenzoates and Benzoates in Foods
Authors: Lewis M H
Published: February 2020

A successful collaborative study was made on the determination of benzoates in solid foods, using the official, first action method for benzoates in liquid and semisolid foods. The method combines steam distillation, TLC, and UV spectroscopy. Recovery data ranged from 94 to 120%. An attempt to separate the parabens by GLC was successful but further work is needed for the quantitative determination of these compounds.