bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Melengestrol Acetate in Feedstuffs with Liquid Chromatographic Preparatory Column Cleanup and Quantitative Analysis
Authors: Weigand Jim L , Dille Daniel S
Published: February 2020

Melengestrol acetate (MGA) is determined by liquid chromatography using a fraction from preparatory LC as a means of sample cleanup for feedstuffs, both dry and liquid. Dry ground feed is Soxhlet extracted with hexane and passed through a 2% deactivated alumina column for initial cleanup. The eluate is evaporated, redissolved in methanol, filtered, and injected onto a preparatory LC column. The fraction containing MGA is separated from the remaining matrix, evaporated to dryness, dissolved in methanol, and quantitated by LC analysis. Liquid supplements are extracted in methanol, and the extract is evaporated to near dryness. The residue is diluted with water, extracted with chloroform, passed through sodium sulfate, and evaporated to dryness. The remaining sample is dissolved in methanol prior to preparative LC and quantitative LC. Recoveries for 2 laboratory- fortified commercial feeds, one dry and one liquid, containing 0.39 and 0.40 mg/lb, were 98.3% ± 4.4 and 95.8% ± 4.3, respectively. Results compare favorably with existing methods. Up to a 4-fold time savings was realized by this method without automation.
Rapid, Low-Cost Cleanup Procedure for Determination of Semivolatile Organic Compounds in Human and Bovine Adipose Tissues
Authors: Liao Wenta , Smith Wendy D , Chiang Tom C , Williams Llewellyn R
Published: February 2020

A gas chromatographic/mass spectrometric (GC/MS) method is described for determination of organic environmental pollutants in human and bovine adipose tissues. Compounds such as organochlorine pesticides, polychlorinated biphenyls, polynuclear aromatic hydrocarbons, polychlorinated aromatics, and brominated aromatics are extracted with organic solvents and separated from coextracted lipids on a Florisil column. The eluate is concentrated and compounds are identified and quantitated by GC/MS analysis. The method was evaluated in a single laboratory for ability to recover compounds of environmental and regulatory importance. Except for a few more polar compounds, such as phthalates and phosphates, recoveries averaged about 85%. The elution system maximized recovery and allowed minimal coelution of lipid materials. Detection limits for most compounds studied were in the range of 5-50 ng/g (ppb).
Simultaneous Determination of Dextrose, Sucrose, Maltose, and Lactose in Sausage Products
by Liquid Chromatography
Authors: Ali M Sher
Published: February 2020

A liquid chromatographic (LC) method for the simultaneous determination of dextrose, sucrose, maltose, and lactose in sausage products has been developed. Dextrose, sucrose, maltose, and lactose are extracted from comminuted meat products with 52% ethanol. After filtration, the extracts are purified by passing them through a C,„ Sep-Pak cartridge and 2 ion exchange resin Econo-columns in series. After concentration and filtration, extracts are analyzed by LC using a normal phase amino column and a differential refractometer detector. Homogeneously ground samples of cooked and fresh sausages are fortified with dextrose, sucrose, maltose, and lactose at 4 different concentrations. Average recovery for dextrose, sucrose, maltose, and lactose at all 4 levels of fortification was greater than 80% with a coefficient of variation less than 10%
Worldwide Occurrence of Mycotoxins in Foods and Feeds—An Update
Authors: Jelinek Charles F , Pohland Albert E , Wood Garnett E
Published: February 2020

In a review presented at the first FAO/WHO/UNEP Conference on Mycotoxins in 1977, the occurrence of aflatoxins, zearalenone, ochratoxin A, citrinin, trichothecenes, patulin, penicillic acid, and the ergot alkaloids was indicated to be significant in naturally contaminated foods and feeds. The information presented on aflatoxin contamination greatly exceeded that for all other mycotoxins combined. This study reviews the worldwide levels and occurrence of mycotoxins in various commodities since 1976. Comparatively few countries have lowered the acceptable levels for aflatoxins in susceptible commodities. However, intensified efforts are needed to establish control of aflatoxin levels in the global food supply, particularly in peanuts, tree nuts, corn, and animal feeds. Extensive deoxynivalenol (DON) contamination of grains, especially wheat, was demonstrated. Co-contamination of grains by Fusarium toxins, especially DON and nivalenol, with zearalenone to a lesser extent, was reported. However, more information on co-occurrence of Fusarium toxins in cereals should be developed. When contamination of feeds by ochratoxin A was significant, this toxin occurred in swine kidney and smoked meats in high levels. On the basis of occurrence and/or toxicity, patulin and penicillic acid contamination of foods does not appear to be of real concern. More recent developments suggest, however, that expanded monitoring studies of Alternaria toxins, moniliformin, citrinin, cyclopiazonic acid, penitrem A, and ergot alkaloids are indicated.
Determination of Nonionic Nonylphenol Ethoxylate Surfactants in Pulp and Paper Mill Process Samples by Spectrophotometry and Liquid Chromatography
Authors: Sithole B Bruce , Allen Lawrence H
Published: February 2020

Complexation with cobaltothiocyanate followed by spectrophotometric measurement was compared with liquid chromatography (LC) for the determination of a nonionic nonylphenol ethoxylate surfactant in pulp and paper mill process samples. LC analysis was found to be superior to spectrophotometry because of the ease and rapidity of the method. The surfactant must be isolated from the sample matrixes by a gas stripping procedure. Recoveries were ≥ 85%. An unbleached Whitewater sample from a mill had a surfactant concentration of 0.31 mg/L.
Enzyme-Linked Immunosorbent Assay for T-2 Toxin Metabolites in Urine
Authors: Lee Rachel C , Wei Ru-Dong , Chu Fun S
Published: February 2020

A direct competitive enzyme-linked immunosorbent assay (ELISA) for determination of total T-2 toxin metabolites in urine was developed. The assay involves coating anti-3-acetyl-neosolaniol-hemisuccinate- bovine serum albumin conjugate (anti-3-Ac-NEOS-HS-BSA) antibody to the ELISA plate and using 3-Ac-NEOS-HS-peroxidase as the enzyme marker. Competitive ELISA revealed that the antibody had good cross-reactivity with acetyldiacetoxyscirpenol (Ac-DAS), T-2 tetraol tetraacetate, 3'-OH-Ac-T-2, 3-Ac-NEOS, and 3,4,15- triacetyl-12,13-epoxytrichothec-9-en-8-one (Ac-T-2-8-one), but less cross-reactivity with Ac-T-2 toxin and T-2 toxin. All metabolites of T-2 toxin in urine were converted to T-2 tetraol tetraacetate (T-2- 4ol-4Ac) by acetylation of the sample extract before ELISA. To test the ELISA accuracy, a radioimmunoassay (RIA) was performed simultaneously. The linear portion of the standard curve of this direct ELISA for T-2-4ol-4Ac was 0.2-2.0 ng/mL, which was 10 times more sensitive than RIA. The minimum detection level for T-2-4ol- 4Ac was 0.02 ng/mL (0.4 pg/assay) in the absence of urine sample. The overall analytical recoveries for T-2 toxin, HT-2, T-2-4ol, 3'- OH-HT-2, NEOS, and a mixture of these 5 toxins added to the urine samples in the ELISA at concentrations of 0.05 and 0.2 ng/mL were 87 and 94%, respectively.
Simultaneous Determination of Alachlor, Metolachlor, Atrazine, and Simazine in Water and Soil by Isotope Dilution Gas Chromatography/Mass Spectrometry
Authors: Huang Lee Q
Published: February 2020

A multiresidue method was developed for the simultaneous determination of low parts per billion (ppb) concentrations of the herbicides alachlor, metolachlor, atrazine, and simazine in water and soil using isotope dilution gas chromatography/mass spectrometry (GC/MS). Known amounts of 15N,13C-alachlor and 2H5-atrazine were added to each sample as internal standards. The samples were then prepared by a solid phase extraction with no further cleanup. A high resolution GC/low resolution MS system with data acquisition in selected ion monitoring mode was used to quantitate herbicides in the extract. The limit of detection was 0.05 ppb for water and 0.5 ppb for soil. Accuracy greater than 80% and precision better than 4% was demonstrated with spiked samples.
Liquid Chromatographic Method for Quantitation of Glyphosate and Metabolite Residues in Organic and Mineral Soils, Stream Sediments, and Hardwood Foliage
Authors: Thompson Dean G , Cowell John E , Daniels Robert J , Staznik Bozena , MacDonald Linda M
Published: February 2020

A liquid chromatographic method for determining glyphosate (GLYPH) and its major metabolite aminomethylphosphonic acid (AMPA) in various environmental substrates is described. Ion-exchange column chromatography is coupled with post-column ninhydrin derivatization and absorbance detection at 570 nm. Use of a valve-switching technique allowed quantitation of both analytes in a single chromatographic run and eliminated slow-eluting, coextracted interferences. The method was successfully used to quantitate GLYPH and AMPA in organic and mineral soils, stream sediments, and foliage of 2 hardwood brush species. Mean recovery efficiencies for GLYPH as determined from fortified blank field samples were as follows: bottom sediment 84%, suspended sediment 66%, organic soils 79%, mineral soils 73%, alder leaf litter 81%, salmonberry leaf litter 84%, and artificial deposit collectors 87%. Precision for GLYPH determination was good with less than 14% coefficient of variation on mean recovery for all substrates. Limits of detection were lowest for sediments (0.01 μg/g dry mass) and highest for foliage substrates (0.10 μg/g dry mass). Using this system, 6 samples/person/day were routinely analyzed.
Zinc from Oyster Tissue as Causative Factor in Mouse Deaths in Official Bioassay for Paralytic Shellfish Poison
Authors: McCulloch A W , Boyd R K , Freitas A S W de , Foxall R A , Jamieson W D , cock M V Lay , Quilliam M A , Wright J L C , Boyko V J , McLaren J W , Miedema M R , Pocklington R , Arsenault E , Richard D J A
Published: February 2020

Toxicity (extreme weakness, body temperature drop, cyanosis, some slow deaths) in test mice, upon intraperitoneal injection of standardmethod paralytic shellfish poison (PSP) extracts of some PSP-free oysters, is consistent with the relatively high levels of zinc in these extracts. As a rough guideline, the threshold for a toxic response corresponds to a drained tissue zinc level of over 900 μg/g. The identification of zinc as the substance responsible has been supported by inducing toxicity in control extracts by spiking with nontoxic levels of zinc, and by eliminating toxicity from toxic extracts by chemical removal (precipitation, ion exchange) of metals.
Sampling and Sample Preparation for Detection and Quantitation of Natural Toxicants in Food and Feed
Authors: Park Douglas L , Pohland Albert E
Published: February 2020

The primary goal of a sampling plan for natural toxins, i.e., mycotoxins and seafood toxins, is to obtain a sample that accurately represents the concentrations of individual components of a given lot. Factors affecting the ability of the sampling plan to accomplish this goal include: (1) nature of the analyte of interest; (2) distribution of the analyte throughout the lot, (3) physical characteristics of the product, (4) accessibility of the product to random representative sampling, (5) sampling procedure, and (6) size of sample. Sampling plans are composed of 3 distinct components: (a) sampling, (b) sample preparation, and (c) analysis. Normally, sampling contributes the largest relative error while analysis comprises the least. Automatic, continuous stream samplers provide the most representative samples for commodities such as nuts, cottonseed, and cereal grains. Good sample preparation equipment is currently available for these commodities; the use of this equipment to obtain a representative test sample is discussed.
Differential Characteristics of Fatty Acids in Cheese from Milk of Various Animal Species by Capillary Gas Chromatography
Authors: Prager Manfred J
Published: February 2020

The kind of milk used in the manufacture of cheese has been identified by analysis of the fatty acids. The milk fat is extracted from the cheese and saponified. The methyl esters of the fatty acids are prepared and determined by capillary column gas chromatography. Seven major fatty acids are separated and quantitated, namely, C8:0, C10:0, C12:0, C14:0, C16:0, C18:0, and C18:l. Many of the 21 simple ratios that can be formed from these 7 quantities are characteristic of the type of milk from which the fatty acids were obtained. The method allows the identification of cheese prepared with the milk of cows, buffalo, sheep, or goats. Substitution or adulteration of milk can also be detected.
Determination of Ergosterol in Cereals, Mixed Feed Components, and Mixed Feeds by Liquid Chromatography
Authors: Schwadorf Klaus , Müller Hans-M
Published: February 2020

A sensitive, rapid, reproducible, and reliable liquid chromatographic (LC) method is described for determination of ergosterol in feedstuffs. The sample is saponified directly and the saponified mixture is extracted with n-hexane. Ergosterol is determined without further purification or cleanup steps by using a liquid chromatograph with a 250 X 4.6 mm column packed with LiChrosorb Si 60, 5 μm, and a high pressure column prefilter. The ultraviolet detector is set at 282 nm. The limit of detection was 0.1 ppm; recovery ranged between 96.7 and 102.2%. Diode array technology is used for identification and peak purity control. Under strong UV irradiation (254 nm) and oxygen or nitrogen atmosphere ergosterol was converted almost quantitatively to ergocalciferol. Under the described conditions of the method, ergosterol proved to be stable. Ergosterol was determined in cereals, mixed feeds (e.g., for swine and poultry), and their components of plant and animal origin. It was not found in carcass meal, meat-and-bone meal, citrus pulps, or molasses; only traces were detected in fish meal.
State Programs for Pesticide Residues in Foods
Authors: Minyard James P , Roberts W Edward , Cobb William Y
Published: February 2020

Two U.S. data collection and dissemination programs, FEEDCON and FOODCONTAM, are described. FEEDCON provides information on contamination levels in animal feeds of toxic chemical residues (pesticides, industrial chemicals, heavy metals, mycotoxins, natural plant toxins, salmonella, and therapeutic drug cross-contaminations). FEEDCON data are collected from approximately 40 state feed regulatory agencies, feed manufacturers, and related groups who subscribe ($100-$200 per year) to the program, which is sponsored by the Association of American Feed Control Officials. FOODCONTAM provides similar information, but is limited to pesticides, heavy metals and industrial chemicals (polychlorinated and polybrominated biphenyls, etc.) in human foods. Both programs have been developed and initiated under U.S. Food and Drug Administration contracts with the Mississippi State Chemical Laboratory. Program structures of both are outlined conceptually, and FOODCONTAM is described in detail. FOODCONTAM data-sharing program development is essentially complete, but expansion by incorporating FDA data with State Laboratory data is nearing reality.
Chemical Test for Mammalian Feces in Grain Products: Collaborative Study
Authors: Gerber Harriet R
Published: February 2020

A collaborative study was conducted to validate the use of the AOAC alkaline phosphatase method for mammalian feces in corn meal, 44.B01-44.B06, for 7 additional products: brown rice cream, oat bran, grits, semolina, pasta flour, farina, and barley plus (a mixture of barley, oat bran, and brown rice). The proposed method determines the presence of alkaline phosphatase, an enzyme contained in mammalian feces, by using phenolphthalein diphosphate as the enzyme substrate in a test agar medium. Fecal matter is separated from the grain products by specific gravity differences in 1% test agar. As the product is distributed on liquid test agar, fecal fragments float while the grain products sink. The alkaline phosphatase cleaves phosphate radicals from phenolphthalein diphosphate, generating free phenolphthalein, which produces a pink to red-purple color around the fecal particles in the previously colorless medium. Collaborators' recovery averages ranged from 21.7 particles (72.3%) for oat bran to 25.3 particles (84.3%) for semolina at the 30 particle spike level. Overall average background was 0.4 positive reactions per food type. The collaborators reported that the method was quick, simple, and easy to use. The method has been approved interim official first action for all 7 grain products.
Determination of Allicin in Garlic and Commercial Garlic Products by Gas Chromatography with Flame Photometric Detection
Authors: Saito Koichi , Horie Masakazu , Hoshino Youji , Nose Norihide , Mochizuki Emiko , Nakazawa Hiroyuki , Fujita Masahiko
Published: February 2020

A simple and rapid method has been developed for the determination of allicin in garlic and commercial garlic products by gas chromatography (GC) with flame photometric detection. Samples containing allicin are homogenized with distilled water and centrifuged. An aliquot of the superaate is cleaned up on an Extrelut column using diethyl ether as an eluant. The GC separation is carried out on a 1% OV-1 or 2% Advance DS+ H3P 0 4 column. The calibration curve was rectilinear in the range from 0.2 to 2.0 pg/mL. The overall recovery of allicin added to garlic and garlic products at 0.4 mg/g was more than 84% with a detection limit of 0.02 mg/g. Allicin was found in spices; whereas, no allicin was found in garlic products marketed as health foods.
Liquid Chromatographic Determination of Desfuroylceftiofur Metabolite of Ceftiofur as Residue in Cattle Plasma
Authors: Jaglan Prem S , Cox Byron L , Arnold Thomas S , Kubicek Marc F , Stuart Dorothy J , Gilbertson Terry J
Published: February 2020

A liquid chromatographic (LC) method has been developed for the determination of the desfuroylceftiofur metabolite of ceftiofur as a residue in the plasma of animals. Plasma sample in 0.1 M pH 8.7 phosphate buffer containing dithioerythritol is Incubated under nitrogen for 15 min at 50°C. The sample is centrifuged, charged to a C18 cartridge, and washed with 0.1M ammonium acetate. The desfuroylceftiofur residue on the cartridge Is derivatized by adding 0.1M ammonium acetate containing iodoacetamide and letting the cartridge stand in the dark for 30 min. The cartridge is then drained and rinsed, and the desfuroylceftiofur acetamide is eluted with methanol. The mixture is evaporated to dryness, dissolved in pH 10.6 sodium hydroxide, and charged to a SAX cartridge. The derivative is eluted with 2% acetic acid, reduced In volume, and dissolved in mobile phase for liquid chromatography. The LC system includes a C8 column and guard cartridge with UV detection at 254 nm. The gradient mobile phase (flow rate 1 mL/mln) is 0.01M pH 5 ammonium acetate programmed to 29 % methanol-water (60 + 40) in 25 min. Recoveries were 90-100% with a sensitivity of 0.1 ppm or less. The procedure has been applied to the plasma of cattle, rats, horses, pigs, and dogs.
Equivalency Of Protein Determination In Feed On Bran & Luebbe Traacs 800 Autoanalyzer With Aoac Semiautomated Method: Minicouaborative Study
Authors: Kane Peter F , Orcutt Anne
Published: February 2020

new generation of autoanalyzers was collaboratively studled for equivalency with instrumentation described in the AOAC method for crude protein in animal feeds. Twenty predigested samples were analyzed by 4 collaborators using standards that were provided. Means were comparable; the overall average difference was 0.07% protein. Analysis of variance indicated no evidence for an instrument difference. The method describing use of the Traacs 800 autoanalyzer as an alternative system has been adopted official first action.
Liquid Chromatographic Determination Of Polydextrose In Food Matrixes
Authors: Noffsinger James B , Emery Martha , Hoch Daniel J , Dokladalova Jarmila
Published: February 2020

A liquid chromatographic (LC) method has been developed to determine the content of polydextrose, a water-soluble 1 calorie/g bulking agent, in food matrixes such as cookies, cakes, fruit spreads, and chocolate toppings. This analysis, which requires use of a blank matrix, provides a feasible means to control the manufacture of foods containing this additive and provides a component for the accurate determination of the caloric value of a particular food product. The method involves aqueous extraction of the polydextrose from the food matrix followed by separation on a carbohydrate analysis column. The LC system uses a mobile phase of 0.005M CaS04*2H2o and a refractive index detector for quantitation. Polydextrose recoveries from the food matrixes varied from 91.5 to 100.9% with assay precision, expressed as coefficient of variation, ranging from 0.7 to 4.3%. Each error estimate was derived from 5 parallel determinations. The present methodology is precise and selective in contrast to the modified classical phenol-sulfuric acid colorimetric method for assaying carbohydrates, which had been used for polydextrose determination in food matrixes in the past. Because the coefficient of variation frequently exceeded 10%, replicate analyses were necessary to achieve quantitation.
Use of Detergents in the Analysis of Fibrous Feeds. II. A Rapid Method for the Determination of Fiber and Lignin
Authors: Soest P J Van
Published: February 2020

The capacity of cetyl trimethylammonium bromide to dissolve proteins in acid solution has been utilized in development of a method, called acid-detergent fiber method (ADF), which is not only a fiber determination in itself but also the major preparatory step in the determination of lignin. The entire procedure for determining fiber and lignin is considerably more rapid than presently published methods. Compositional studies show ADF to consist chiefly of lignin and polysaccharides. Correlations with the new fiber method and digestibility of 18 forages (r = —0.79) showed it to be somewhat superior to crude fiber (r = —0.73) in estimating nutritive value. The correlation of the new lignin method and digestibility was —0.90 when grass and legume species were separated.
Determination of Ellagitannins in Extracts of Oak Wood and in Distilled Beverages Matured in Oak Barrels
Authors: Puech Jean-Louis , Rabier Philippe , Bories-Azeau Jérôme , Sarni Farid , Moutounet Michel
Published: February 2020

A method Is described for determination of ellagitannins In ethanol-water extracts of oak wood and In distilled alcoholic beverages matured In oak barrels. It Is based on the combined ellagic acid content according to ellagltannln structure. Hydrolysis was carried out In the presence of hydrochloric acid under reflux in a 100°C oil bath for 3 h. Total ellagic acid was thus determined by liquid chromatography (LC), and the free ellagic acid content present in the ethanolwater media was subtracted, the difference being the combined ellagic acid content corresponding to ellagitannins. A 5 μm C18 column was used with detection at 254 nm. The method Is specific for ellagitannins, which Is an advantage over other analytical techniques for overall evaluation of these substances extracted from wood. Results for spirits distilled from wine, grain, and sugarcane were highly variable.
Improved Gas Chromatographic Method for Determination of Daminozide by Alkaline Hydrolysis and 2-Nitrobenzaldehyde Derivatization and Survey Results of Daminozide in Agricultural Products
Authors: Steinbrecher Kurt , Saxton Wilbur L , Oehler George A
Published: February 2020

An improved method was developed for the quantitative determination of daminozide. This new method combines the alkaline hydrolysis and distillation steps of the PAMII method for daminozide with the derivatization, cleanup, and gas chromatographic determination steps of the Wright method for unsymmetrlcal dimethyl hydrazine (UDMH). The minimum detectable level Is 0.05 ppm. Recoveries range from 85 to 110% when daminozide Is added at 0.1 to 1.0 ppm, and are generally 40% at the 0.05 ppm level. A variety of domestic and imported products were analyzed by this Improved method and daminozide was detected In 33 of the 98 samples analyzed. Levels detected ranged from a trace amount to 0.80 ppm. The Identity of UDMH hydrazone was confirmed by mass spectrometry In many samples, thus confirming the presence of daminozide. Two samples containing daminozide were analyzed Independently by a second laboratory and the findings were closely duplicated.
Determination of Phenol in Honey by Liquid Chromatography with Amperometric Detection
Authors: Takeba Kazue , Matsumoto Masao , Shida Yasuo , Nakazawa Hiroyuki
Published: February 2020

A sensitive, selective analytical method has been developed for determination of phenol In honey by liquid chromotography (LC) with amperometric detection (AMD). Phenol Is extracted with benzene from the distillate of honey. The benzene extract Is washed with 1% sodium bicarbonate solution and then reextracteed with 0.1N sodium hydroxide followed by cleanup on a C18 cartridge. Phenol Is determined by reverse-phase LC with amperometric detection. An Inertsil ODS column (150 X 4.6 mm, 5 μm) is used In the determination. The mobile phase Is a mixture (20 + 80 v/v) of acetonitrlle and 0.01M sodium dihydrogen phosphate containing 2mM ethylenediamlnetetraacetic acid, disodlum salt (EDTA) with the pH adjusted to 5.0. The flow rate is 1 mL/mln under ambient conditions. The applied potential of the AMD using a glassy carbon electrode Is 0.7 V vs an Ag/AgCI reference electrode. Average recoveries of phenol added to honey were 79.8% at 0.01 ppm spiking level, 90.4% at 0.1 ppm, and 91.0% at 1.0 ppm. Repeatabillties were 3.4, 1.3, and 1.8%, respectively. The detection limit of phenol In honey was 0.002 ppm. For analysis of 112 commercial honey samples, the range and average values of 32 detected samples were 0.05-5.88 ppm and 0.71 ppm, respectively.
Determination of Diclofenac Sodium and Related Compounds in Raw Materials and Formulations
Authors: Beaulieu Normand , Lovering Edward G , Lefrancois Johanne , Ong H
Published: February 2020

A liquid chromatographic method has been developed for determination of drug and related compounds In diclofenac sodium raw material, slow-release, and enteric coated tablets. The method specifies a 5μm octadecylsllane bonded phase column, a mobile phase of tetrahydrofuran-acetonltrlle- buffer, pH 5 (1 + 4 + 8.3), and detection at 229 nm. The method resolves 10 known related compounds with limits of quantitation of 0.2% or less. Seventeen drug raw material samples were evaluated. Total Impurity levels ranged from 0.1 to 0.9%. The method has also been used for determination of drug content In raw materials and formulations. Mean assay levels In drug raw materials ranged between 98.3% and 101.8%.
Gas Chromatographic Determination of Total Iodine in Foods
Authors: Mitsuhashi Takao , Kaneda Yoshio
Published: February 2020

A gas chromatographic (GC) method has been developed for determination of total Iodine In foods, based on the reaction of Iodine with 3-pentanone. Organic matter of a sample is destroyed by an alkaline ashing technique. Iodide In a water extract of the ash residue is oxidized to free Iodine by adding dlchromate in the presence of sulfuric acid. Liberated Iodine Is reacted with 3-pentanone to form 2-lodo-3-pentanone, extracted Into n-hexane, and then determined by gas chromatography with an electron-capture detector. Recoveries of Iodide from spiked food samples ranged from 91.4 to 99.6%. Detection limit for iodine Is 0.05 μg/g
Fast and Simple Liquid Chromatographic Determination of Nonphosphorylated Thiamine in Infant Formula, Milk, and Other Foods
Authors: Nicolas Edgar C , Pfender Kathleen A
Published: February 2020

A very fast and simple method for determination of nonphosphorylated thiamine In Infant formula products, milk, and other nonfortlfled foods using reverse-phase ion-pairing liquid chromatography (LC) has been developed. Sample preparation consists of merely acid treatment to precipitate protein, followed by gravity filtration. No concentration, extraction, derlvatlzatlon, or preliminary column cleanup is necessary. The chromatography Is done on /tBondapack C18 with an aqueous mobile phase containing 0.15% sodium hexane sulfonate, 20% MeOH, 1.5% HOAc, and 0.1 % EDTA at a flow rate of 2.5 mL/mln. Ultraviolet detection at 248 nm Is used. A typical run takes 7 mln, and 60 samples can be processed In 4 h. Results average from 96 to 104% of theory for the Infant formula products analyzed. A 99 to 103% recovery of spike has been demonstrated. Method precision Is good (2 to 4% RSD, short-term, and 2 to 5% RSD, longterm, depending on sample type). Peak separation from thiamine phosphate esters Is achieved. Specificity Is demonstrated by UV spectral scan and absorbance ratios. Equivalency to a microbial method (validated against the official AOAC fluorometrlc method) was established. The method Is used for high-volume quality control testing of milk-based Infant formula products In the ready-to-use, concentrate, or powder form
In Vivo Rat Assay for True Protein Digestibility: Collaborative Study
Authors: Mcdonough Frank E , Steinke Fred H , Sarwar Ghulam , Eggum Bjorn O , Bressani Ricardo , Huth Peter J , Barbeau William E , Mitchell Geraldine V , Phillips John G
Published: February 2020

Eight laboratories participated In a collaborative study to estimate precision of a standardized rat assay for determining true protein digestibility In selected animal, fish, and cereal products. Each of 7 test protein sources (casein, tuna fish, macaroni/cheese, pea protein concentrate, rolled oats, pinto beans, and nonfat dried milk) was fed as the sole source of protein at a 10% protein level in mixed diets. Each diet was fed to 2 replicate groups of 4 rats each for a 4-day acclimation period and a 5-day balance period. Mean digestibilities ranged from 98.6% for casein to 72.6% for pinto beans. Repeatability standard deviations ranged from 0.5 to 2.0%; the mean relative standard deviation for repeatability was 0.9% (range 0.5-2.8%). Reproducibility standard deviations ranged from 1.2 to 3.2%, and the mean relative standard deviation for reproducibility was 2.4% (range 1.3- 4.4%). The method has been approved interim official first action for determining true protein digestibility In foods and ingredients
Application of a Tri-Enzyme Extraction for Total Folate Determination in Foods
Authors: Martin James I , Landen William O , Soliman Abdel-Gawad M , Eitenmiller Ronald R
Published: February 2020

A tri-enzyme digestion procedure using chicken pancreas conjugase, a-amylase, and Pronase® was evaluated to determine Its usefulness In the microbiological quantitation of total folate In foods. Folate values obtained by traditional conjugase digestion were compared to those obtained by the tri-enzyme method for 12 food products that represent diverse matrixes. The tri-enzyme treatment Increased measurable folate from most foods when compared to levels found after conjugase digestion. Largest Increases were noted for tuna fish (51%) and yogurt (33%) after tri-enzyme digestion. For the 12 foods, a mean increase of 19% In measurable folate was obtained with tri-enzyme treatment. The study shows that traditional conjugase treatment does not completely free folate from complex food matrixes before microbiological analysis. Further, as other Investigations have suggested, current accepted methods for folate analysis may be underestimating folate levels In foods
Titrimetric Determination of Some Penicillins Using 2-Iodoxybenzoate
Authors: Belal, F , El-Brashy A , Ibrahim F
Published: February 2020

A simple semlmlcro titrimetric assay procedure Is described for determination of 6 semisynthetic penicillins, namely: ampiclllin, amoxicillin, benzylpenlclllin, epiclllln, hetaclllin, and phenoxymethylpenlcillln In addition to penicillamine. The method Involves the use of 2-lodoxybenzoate as a standard solution, whereby a known, excess volume Is added to the penicillins in acid medium and, after the specified time, the residual reagent is iodometrically determined. The molar ratio of the reaction Is assessed and a possible pathway for the mechanism of the reaction is suggested and confirmed through thin-layer chromatography (TLC) study of the reaction products. The proposed method is then applied to determination of the studied compounds In their dosage forms. Results obtained are in good agreement with those obtained by official methods.
Liquid Chromatographic Determination of Domoic Acid in Mussels, Using AOAC Paralytic Shellfish Poison Extraction Procedure: Collaborative Study
Authors: Lawrence James F , Charbonneau Claudette F , Ménard Cathie
Published: February 2020

A liquid chromatographic method using the AOAC paralytic shellfish poison (PSP) extraction procedure for domoic acid, a marine toxin, in mussel tissue was collaboratively studied in 10 laboratories. Domoic acid is extracted by boiling the homogenized tissue for 5 min with 0.1N HCI. The mixture is cooled, diluted to a known volume, and then centrifuged. An aliquot of the supernate Is diluted, filtered, and analyzed by reverse-phase liquid chromatography with a mobile phase containing acetonitrile and water adjusted to about pH 2.5. Each collaborator received a prepared standard solution, a practice sample, and 7 randomly numbered unknown samples (1 blank mussel tissue, 1 spiked at 14.1 µg domoic acid/ g, 1 spiked at 18.9 µg/g, and duplicate samples with naturally Incurred domoic acid at 75 µ/g and at 186 µ/g). Five of the laboratories had little or no experience In domoic acid analysis. Ten of 11 laboratories completed the study and submitted results. Two Individual values out of a total of 70 were found to be outliers. Mean recovery of domoic acid from the spiked extracts was 75%. Relative standard deviations between laboratories (RSDR) ranged from 7.5 to 19.4%; wlthln-laboratory RSDs (RSDr) for the 2 blind duplicate pairs were 1.9 and 4.8%. The detection limit was about 1 fig domoic acld/g. The method has been adopted official first action by AOAC.
Variance and Representativeness of the AOAC Sampling Procedure for Bagged Fertilizer
Authors: Terry David L , Nelson Larry , Stevens James , Caine Douglas , Johnson Frank , Huber Edward , Huber Edward
Published: February 2020

The present paper evaluates both the variances and representativeness of the AOAC sampling procedure for bagged fertilizer (929.01a, 15th Ed., 1990) for concentrations of total nitrogen, available phosphoric acid, and soluble potash from 5% to 30% In blended, mixed fertilizers using materials In common use In 1983. The sampling variances determined did not differ significantly from sampling variances determined in earlier studies that are currently used by the Association of American Plant Food Control Officials (AAPFCO). The representativeness of the AOAC sampling procedure for bagged fertilizer was evaluated by testing the differences between AOAC bag sample means and rotary divider sample means (riffled down bags) of the blends (a) using AAPFCO investigational allowances (lAs) and (b) using t-tests. When AAPFCO lAs were used, there were only 2 bag means significantly below the rotary divider means. When t-tests were used, the bag means tested significantly lower than the rotary means for the 5, 10, 15, and 20% N blends and the 15% P205 blend. The bag means for the 5,10, and 30% P205 blends were significantly above the rotary means. There were no significant differences between bag and rotary means for K2O In any blends. Because Mests are more sensitive than AAPFCO lAs, smaller differences are judged to be significant. Based on AAPFCO lAs, the AOAC sampling procedure for bagged fertilizer probably satisfactorily represents what is In the bag. However, significantly lower N and higher P205 bag means based on Mests are cause for concern and should spur activity In determining the nature of this phenomenon, interlaboratory variances were also determined and evaluated. These tended to verify those In current use by AAPFCO. The representativeness of the AOAC stream sampling procedure (929.01b) was also evaluated and found to be an acceptable method for determining the true analysis of a blend.
Multiresidue Screen for Organophosphorus Insecticides Using Gel Permeation Chromatography—Silica Gel Cleanup
Authors: Holstege Dirk M , Scharberg David L , Richardson Elizabeth R , Möller Gregory
Published: February 2020

A multiresidue screen for quantitative determination of 43 organophosphorus insecticides In 5 g of plant and animal tissues Is described. The organophosphorus insecticides are extracted with methanol-dichloromethane (10 + 90, v/v) and cleaned up using automated gel permeation chromatography with hexane-ethyl acetate (60 + 40) eluant and in-line silica gel minicolumns. Concentrated extracts are analyzed by gas chromatography with flame photometric detection. The method recovers 43 organophosphorus insecticides in the range of 72 to 115%. Analysis of fortified bovine liver (n = 5) shows an average 95.9 ± 4.8% recovery at the 0.05 μg/g level and 93 ± 3.8% at the 0.5 μg/g level. Analysis of fortified bovine rumen content (n = 5) shows an average 98 ± 4.2% recovery at the 0.1 μg/g level and 98.7 ± 2.8% at the 1 μg/g level. Method detection limits ranged from 0.01 to 0.05 μg/g for the compounds studied using a nominal 5 gram sample.
Matrix Solid Phase Dispersion(MSPD) Extraction and Gas Chromatographic Screening of Nine Chlorinated Pesticides in Beef Fat
Authors: Long Austin R , Soliman Maher M , Barker Steven A
Published: February 2020

A multiresldue technique Is presented for the extraction and quantitative gas chromatographic screening of 9 insecticides (lindane, heptachlor, aldrin, heptachlor epoxide, p.p'-DDE, dleldrln, endrin, p,p'-TDE, and p.p'-DDT) as residues In beef fat. Beef fat was fortified by adding the 9 Insecticides, plus dlbutyl chlorendate as Internal standard, to 0.5 g portions of beef fat and blending with 2 g C18 (octadecylsllyl)-derivatlzed silica. The C18/fat matrix blend was fashioned into a column by adding the blend to a 10 mL syringe barrel containing 2 g activated Florisll. The insecticides were then eluted from the column with 8 mL acetonitrile, and a 2μL portion of the acetonitrile eluate was then directly analyzed by gas chromatography with electron capture detection. Unfortified blank controls were treated similarly. The acetonitrile eluate contained all of the pesticide analytes (31.25-500 ng/g) and was free of interfering co-extractants. Correlation coefficients for the 9 extracted pesticide standard curves (linear regression analysis, n = 5) ranged from 0.9969 (±0.0021) to 0.9999 (±0.0001). Average relative percentage recoveries (85 ± 3.4% to 102 ± 5.0%, n = 25 for each insecticide), inter-assay variability (6.0 ± 1.0% to 14.0 ± 6.7%, n = 25 for each insecticide), and intra-assay variability (2.5-5.1%, n = 5 for each insecticide) indicated that the methodology is acceptable for the extraction, determination, and screening of these residues in beef fat.
Enzyme Immunoassay for Hen Egg White Lysozyme Used as a Food Additive
Authors: Yoshida Ayako , Takagaki Yutaka , Nishimune Takahiro
Published: February 2020

An Indirect competitive enzyme immunoassay for hen egg white lysozyme (HEL) used as a food additive was investigated. Anti-HEL antibodies were obtained from B10A mouse ascites immunized by Intraperitoneal Injection of HEL. HEL samples to be assayed were extracted from foods with 1 % gelatin in borate buffer. Goat anti-mouse IgG (H+L)-peroxidase complex was used as a second antibody, and 3,3',5,5'- tetramethylbenzidine was used as a substrate for the peroxidase. The working range for quantitative analysis was 1-50 ng/mL, because in this range the binding inhibition curve of anti-HEL antibodies to HEL-coated plates by HEL was linear. Even after losing the lysozyme activity by heat treatment, HEL could be detected by indirect competitive enzyme immunoassay. Recoveries of HEL by this assay were >85 % for Japanese noodles and Japanese traditional-style confectioneries, 53—95% for Miso and cooked beans, and 30—85% for fried fish pastes. HEL contents of 55 commercial foods were determined; HEL was detected in 19 samples in the range 25-20 000 ng/g. HEL as a food additive was detected more frequently In plant-derived foods than in foods of animal origin.
Multielement Concentrations in Liver and Kidney Tissues from Five Species of Canadian Slaughter Animals
Authors: Salisbury Craig D C , Chan Wayne , Saschenbrecker Peter W
Published: February 2020

The present paper describes results of a national survey conducted between 1982 and 1989 to determine residues of arsenic, cadmium, copper, mercury, lead, selenium, and zinc in Canadian slaughter animals. Liver and kidney tissues from cattle, swine, poultry, horses, calves, and sheep were tested. Arsenic was found in most avian and porcine samples, and their respective means of 0.36 and 0.26 μg/g in liver were 7 to 12 times higher than mean concentrations found in the other species. Cadmium was found in the tissues of all species; however, levels were consistently highest in equine samples with mean values of 3.09 and 27.7 μg/g in liver and kidney, respectively. Copper levels >150 μg/g were found predominantly in liver from calves and sheep, with values considerably lower in the remaining species. Mercury levels were low or not detected in all species except horses. Ninety % of equine kidneys and 54% of equine livers had mercury concentrations >0.01 μg/g, with mean values of 0.18 and 0.06 μg/g, respectively. Lead was found in tissues of all species; however, values >2 μg/g were found only in 2 kidneys from adult cattle and 1 kidney from a horse. Selenium, tested only in cattle, was found at mean concentrations of 0.28 μg/g in liver, and 0.92 μg/g in kidney. Relatively high zinc levels were found in livers of horses, pigs, and calves, with respective mean concentrations of 67.3, 65.6, and 70.2 μg/g.
Liquid Chromatography of Pesticide Formulations Containing Dicamba, 2,4-D, and MCPP
Authors: Larson Richard D , Houglum Joel E
Published: February 2020

The present paper describes a reverse phase liquid chromatographic method for assay of samples that combine dicamba, 2,4-D, and MCPP In herbicide formulations. Samples are diluted with isopropanol-water (2 + 1) and chromatographed on a C-18 column with a gradient mobile phase of increasing acetonitrlle concentration with 2% acetic acid solution as the aqueous phase. After an initial hold time of 5 min, the gradient is increased from 25 to 40% acetonitrlle over 10 min. With a flow rate of 1.5 mL/mln, dicamba, 2,4-D, and MCPP elute at 6, 13, and 16.5 min, respectively. The wlthin-day coefficient of variation was 0.1 to 3.2%; between-day variation was 0.6 to 5.5%. The method separates the 3 herbicides from major potential impurities. This method differs from the AOAC official method in that it uses 2% acetic acid in the mobile phase, a gradient flow, no Internal standard, and a data handling system to quantitate the 3 herbicides from the same injection.
A Qualitative Colorimetric Test for Brominated Vegetable Oil in Soft Drinks
Authors: Murthy M N Krishna , Rajalakshmi S , Satyabodha J A , Nagaraja K V
Published: February 2020

A simple and precise method of detecting brominated vegetable oil (BVO) in soft drinks Is described. After extraction of BVO using diethyl ether, the concentrated ethereal solution was treated with a small quantity of zinc dust to convert the organic bromide to inorganic form; the solution was subsequently treated with lead dioxide to liberate bromine. The bromine evolved was detected by means of fluoresceinimpregnated filter paper strip that turns pink because eosin is formed. The test can detect as low as 10 ppm (2 mg/200 mL) of BVO under experimental conditions. Gas chromatography was carried out on sodium methoxide derivatives prepared from ether extract for quantitation.
Simplified Method to Measure Suspensibility of Water Dispersible Powder
Authors: Ogawa Masao , Ohtsubo Toshiro , Tsuda Shigenori , Tsuji Kozo
Published: February 2020

Simplified methods to measure the suspensibility of water dispersible powder (WP) were investigated. These methods were modified from CIPAC (Collaborative International Pesticides Analytical Council) MT 15.1. WPs in this study were prepared using fenttrothlon and procymidone, representing liquid and solid active Ingredients, respectively. The most simplified measuring method was modified by: (1) deleting the suspension preparation step; (2) analyzing the top 9/1 Oths Instead of the bottom 1/1 Oth; and (3) deleting the process of evaporating water from a suspension pipetted from the top 9/1 Oths. Suspensibility determined by this method compared favorably to results obtained by the CIPAC method, and was reproducible. This method required about 40% of the time needed to perform the CIPAC method. Furthermore, this method is suitable for both WPs made with both liquid and solid active ingredients.
Supercritical Fluid Extraction/Enzyme Assay: A Novel Technique to Screen for Pesticide Residues in Meat Products
Authors: France John E , King Jerry W
Published: February 2020

The novel combination of supercritical fluid extraction (SFE) with an enzyme assay system has been used to screen meat products to detect the presence of pesticides. Analytes are collected in water by expanding supercritical carbon dioxide to atmospheric pressure through a restrictor and into an aqueous phase. The solution is then tested for the presence of pesticide residues by enzyme assay. Two experimental approaches have been used. Alachlor-fortified lard and bovine liver were monitored by static SFE coupled with an enzyme immunoassay. SFE of carbofuran-fortified frankfurters was coupled with an enzyme assay based on cholinesterase inhibition. A major benefit of the SFE/enzyme assay technique over conventional screening techniques is that the analyst is not exposed to organic solvents.
Polyvinyl Chloride Matrix Membrane Electrodes for Manual and Flow Injection Analysis of Chloroquine in Pharmaceutical Preparations
Authors: Hassan Saad S M , Ahmed Mona A
Published: February 2020

Two types of polyvinyl chloride (PVC) matrix membrane electrodes responsive to the antimalarial drug chloroquine have been constructed, electrochemically evaluated, compared, and used in pharmaceutical analysis. Type 1 is the classic PVC model with chloroquine-tetraphenylborate (TPB) sensor; Type 2 is a coated silver disk without internal filling solution. Both electrode types exhibited rapid linear potentiometric response to the logarithmic concentration of diprotonated chloroquine cation in the 10−1–10−6M range with calibration slopes 28-30 mV/concentration decade over the pH range 1.8-6.2. These electrodes were sensitive enough to permit determination of chloroquine phosphate at concentrations as low as 5 μg/mL with good accuracy and precision. Determination of chloroquine in various pharmaceutical preparations using direct potentiometry and potentiometric titration with NaTPB gave an average recovery of 98.8% of the nominal values (SD 0.5%). The Type 2 electrode was also assessed in a flow-through sandwich cell for flow injection analysis. Results were compared with data obtained by the U.S. Pharmacopeia method.
Automated Conductance Method for the Detection of Salmonella in Foods: Collaborative Study
Authors: Gibson Donald M , Coombs Philip , Pimbley David W
Published: February 2020

Seventeen laboratories participated in a collaborative study to validate an automated conductance method for the rapid detection of Salmonella in food. The conductance method was compared with the standard BAM/AOAC method for the Isolation of Salmonella. Media for the conductance method were supplied In ready-to-use, disposable, singleuse cells of a novel, unique design. Samples of coconut, fish meal, prawns, nonfat dried milk, liquid egg, and minced beef were artificially contaminated with different Salmonella serotypes to 2 target levels of 1-5 cells/25 g and 10-50 cells/25 g. Each participating laboratory tested 10 contaminated and 5 noncontaminated samples per product. Results showed no significant difference between BAM/AOAC and conductance methods. The conductance method was adopted by AOAC International as a first action method.