bluuebunny/crossref_metadata_2025 huggingface dataset:
Relative Retention Time Diagram as a Useful Tool for Gas Chromatographic Analysis and Electron-Capture Detection of Pesticides
Authors: Omura Masami , Hashimoto Kumiko , Ohta Kunio , Iio Tomoyuki , Ueda Shigekazu , Ando Keiko , Hiraide Hikaru , Kinae Naohide
Published: February 2020

To establish efficient operating conditions for gas chromatographic (GC) analysis of pesticides that are detected by electron-capture detector (ECD), separation degrees of 40 pesticides and their relative retention times (RRT) vs aldrin were determined. Eleven liquid phases, categorized according to the McReynolds constant (MC), were used: OV-1, OV- 3, DC-550, and OV-17 as non- or low polar liquid phases (MC ≦ 1000), OV-22, QF-1, and XE-60 as medium polar liquid phases (1000 < MC ≦ 2000), PEG-20M, DEGA, and DEGS as high polar liquid phases (2000 < MC), and a mixture of DC-200 and EPON1009. An RRT diagram was prepared by plotting the RRT of each pesticide on the horizontal axis and the MC values on the vertical axis. The RRT diagram could be used to describe the properties of pesticides—their behavior on each liquid phase and the precise operational conditions for qualitative GC analysis. The non- or low polar liquid phases were best suited for GC analysis of organochlorine pesticides having low polarity. Their detection limits ranged from 0.01 to 1.0 ng.
Near Infrared Reflectance Spectroscopy. I. Calibration Techniques for Forage Quality Assessment
Authors: Barton Franklin E , Burton G W , Monson W G
Published: February 2020

It is very time consuming and resource costly to rank forages by wet laboratory methods; therefore, near infrared reflectance spectroscopy (NIRS) was used to evaluate hybrid bermudagrass (Cynodon dactylon (L.) Pers.) cultivars for improvements In quality. Quality was assessed by the determination of acid detergent fiber (AOF), crude protein (CP), dry matter (DM), and in vitro dry matter digestibility (iVDMD). The samples were taken from plant breeding trials from 1983,1984,1985, and 1986. They included 32 cultivars, 4 cuttings, and 5 replications each for a total of 640 possible observations per year. This paper describes the process by which the NIR spectrometer was calibrated for each constituent and the effect of various methods of calibration on the performance of the NIRS system to determine quality in bermudagrass hybrids. Excellent one-year equations were obtained from calibrations using the bermudagrass parents in the 1983 samples (R2 = 0.83, 0.97, 0.70; SEC = 0.94, 0.76, 3.64, for ADF, CP, and IVDMD, respectively). Attempts to use outside populations did not produce equivalent results for the first year. The 1983 equations did not fit the 1984 and 1985 samples because of changes that were made to the spectrometer and the yearly differences in the samples. The instrument was then recalibrated with a diverse set of legumes and grass hay samples that contained some bermudagrass. These open population calibrations adequately ranked the bermudagrass entries. We documented that bermudagrass genotypes can be quickly and precisely ranked for forage quality traits via use of open population NIRS calibration equation.
Hypoglycin A Content in the Aril, Seeds, and Husks of Ackee Fruit at Various Stages of Ripeness
Authors: Chase G William , Landen William O , Soliman Abdel-Gawad M
Published: February 2020

Recently, hypoglycin A (HG-A), a natural toxin, was detected in canned ackee fruit. To determine the source of contamination, the HG-A content in the ackee fruit components (aril, seeds, and husks) at various stages of ripeness was determined by a method using an amino acid analyzer. HG-A concentrations in the unripe ackee fruit components were 939, 711, and 41.6 mg/100 g of seed, aril, and husk components, respectively. Analysis of the ripe fruit components showed that HG-A in the seed decreased to 269 mg/100 g and remained unchanged in the husk while the concentrations in the edible ripe aril decreased below the detection limit of 1.2 mg/100 g.
Mass Spectrometric Confirmation of the Presence of N-Nitrosopyrrolidine in Instant Coffee
Authors: Sen Nrisinha P , Seaman Stephen W , Weber D
Published: February 2020

Traces of N-nitrosopyrrolidine (NPYR) may occur in some samples of both instant coffee and fine-ground roasted coffee. The identity of NPYR in 2 samples of instant coffee was confirmed by mass spectrometry as well as by liquid chromatography- thermal energy analysis. A 2-step cleanup procedure, involving fractionation on basic alumina followed by gradient elution on reverse-phase C18 cartridge, is described that allows full-scan mass spectrometric confirmation of NPYR in tested samples.
Evaluation Of Protein Digestibility-Corrected Amino Acid Score Method For Assessing Protein Quality Of Foods
Authors: arwar Ghulam , Mcdonough Frank E
Published: February 2020

The current concepts of protein quality evaluation were reviewed. A detailed examination of existing animal assays and more promising amino acid scoring methods has been carried out by an Ad Hoc Working Group on Protein Quality Measurement for the Codex Committee on Vegetable Proteins during the last 5 years. Several factors such as Inadequacies of protein efficiency ratio (PER, the poorest test) and other animal assays, advancements made In standardizing methods for amino acid analysis and protein digestibility, availability of data on digestibility of protein and Individual amino acids in a variety of foods, and reliability of human amino acid requirements and scoring patterns were evaluated. On the basis of this evaluation, amino acid score, corrected for true digestibility of protein, was recommended to be the most suitable routine method for predicting protein quality of foods for humans. Amino acid scores corrected for true digestibility of protein (as determined by rat balance method) were termed "protein digestibility-corrected amino acid scores." A detailed method for the determination of the protein digestibility-corrected amino acid score was proposed, and information about the range of scores to be expected In foods or food products was provided In the present Investigation. The protein digestibility-corrected amino acid score method Is a simple and scientifically sound approach for routine evaluation of protein quality of foods. Accuracy of the method would, however, be confirmed after validation with growth or metabolic balance studies In humans.
Determination of Thiabendazole, 5-Hydroxythiabendazole, Fenbendazole, and Oxfendazole in Milk
Authors: Tai Susan S.-C , Cargile Nancy , Barnes Charlie J
Published: February 2020

The liquid chromatographic determination previously developed for benzlmldazoles in cattle liver has been slightly modified and applied to the determination of 4 benzlmldazoles In milk. Recoveries of fenbendazole (FBZ), oxfendazole (OFZ), and thiabendazole (TBZ) from milk fortified at the 10 ppb level were 80% or greater with an Intralaboratory coefficient of variation of 11 % or less. Recovery of 5-hydroxythiabendazole (5-OH-TBZ) at the 30 ppb level averaged 56% with an Intralaboratory coefficient of variation of 5%. Limited data on the depletion of FBZ, OFZ, TBZ, and 5-OHTBZ In milk were also generated.
Liquid Chromatography and Fluorescence Detection of Vitamin A in Animal Feeds, Finished Feeds, and Premixes
Authors: Thorpe Virginia A
Published: February 2020

A simple liquid chromatographic method for vitamin A (retinol) in animal feeds is described. The feed is saponified, diluted to minimize interferences, and extracted Into petroleum ether with a single step. The analysis is sensitive and specific with liquid chromatography and a fluorescence detector. The minimum level of detection is 15 ng/mL, which Is equivalent to 10 000 units/lb vitamin A. The method Includes a stable and reproducible standardization of vitamin A that Is used to calibrate standard peak heights In terms of units retlnol/mL. Guarantees of 10 000 units/lb up to premix levels can be analyzed with good recoveries and precision.
Liquid Chromatographic Determination of Pindolol and Related Compounds in Raw Materials
Authors: Lacroix P M , Moir D , Lovering E G
Published: February 2020

A liquid chromatographic method for the assay of pindolol and related compounds In the bulk drug has been developed. The method resolves 6 known and several unknown impurities from the drug and each other by using a nitrile column, an acetonitrlle-sodlum acetate buffer (35 + 65), and a UV detector set at 219 nm. Minimum quantifiable amounts of Impurities are 0.02% or less relative to the drug. Ten lots of pindolol raw material were evaluated for purity and drug content. Total levels of Impurities In these samples, quantltated against pindolol, ranged from about 0.03 to 0.24%. Assay results were within the range of 98.5 to 101.5%.
High-Performance Immunoaffinity Chromatography for Drug Residue Analysis
Authors: Katz Stanley E , Brady Marietta Sue
Published: February 2020

High-performance Immunoaffinity chromatography (IAC) is a potentially strong analytical tool for measurement of drug residues In various matrixes. Although the use of Immunoaffinity separations Is not new, the application to drug residue analysis Is in its Infancy. The present paper discusses the production and purification of antibody, the preparation of columns, the theoretical basis of the analytical separation and elutlon, and variations of the analytical approach.
Diagnostic Data Evaluation. Part VI. Data Evaluation to Establish Product Standards
Authors: Malanoski Anthony J
Published: February 2020

Cooked corned beef was studied to evaluate the feasibility of monitoring the product by means of chemical analysis. The protein fat-free value and the molsture.-protein ratio were evaluated with respect to variability. The molsture:proteln ratio was not as effective as the former because of the greater variability and the requirement for additional analyses.
Flour Acidity Comparisons as Related to Fat Acidity Methods of the Association of Official Analytical Chemists and the International Organization for Standardization
Authors: Parker Gregory D , Lane Ralph H
Published: February 2020

Acidity data were compared of selected flour samples obtained by methods of the International Organization for Standardization (ISO) and the Association of Official Analytical Chemists (AOAC) with and without toluene as a part of the titration medium. In all cases, the ISO method produced significantly higher fat acidity values (P < 0.001) than the AOAC method, probably as a result of greater extraction of acidic materials with the more polar solvent, 95% alcohol, than with petroleum ether. Except for a whole wheat flour sample, no differences (P > 0.05) existed between fat acidity values produced by AOAC methodology consisting of titration of the evaporated petroleum ether extract of the flour in a medium of equal volumes of 95% alcohol and toluene as prescribed In the official method (14.069-14.071), or In a medium of 95% alcohol alone. Based on the data and the potential toxicity of toluene, a collaborative study Is recommended to determine the Influence of Its removal from the official AOAC method. Fat
Determination of Taurine in Infant Formulas Using Ultrafiltration and Cation-Exchange Chromatography
Authors: Nicolas Edgar C , Pfender Kathleen A , Aoun Michael A , Hemmer Jane E
Published: February 2020

A fast and simple method for determination of taurine in Infant formulas has been developed. The sample preparation uses disposable ultrafiltration cartridges to remove protein and clarify the sample. Hydrolysis Is avoided, simplifying the procedure and increasing efficiency. One mL sample Is centrlfuged In a cartridge for 45 mln. The filtrate Is diluted with pH 2.2 citrate buffer and Injected into a high performance amino acid analyzer. A cation-exchange column (sodium phase) Is used with a single buffer eluant and an Isocratic chromatographic program. Colorimetrlc detection is performed following post-column nlnhydrln reaction. Chromatographic resolution from other nlnhydrln-posltive compounds is excellent. Average recoveries for 3 levels of spike for various products were 100-102%. Precision Is 1-3% RSD, depending on product. Linearity, specificity, and ruggedness are excellent. The method Is applicable to quality control testing of milk-based, soy-based, and prehydrolyzed proteinbased Infant formulas In the ready-to-use, concentrate, and powder forms. A variety of commercially available Infant formulas from different manufacturers were analyzed and all were found to contain taurine levels comparable to human milk. Some human milk and cow's milk samples were also analyzed and results compare well with literature values
Determination of Biphenyl Residues in Citrus Fruit by Derivative Infrared Spectrophotometry
Authors: Losada P Paseiro , Lozano J Simal , Gándara J Simal
Published: February 2020

A method for determination of biphenyl residues In whole citrus fruit Is described. The mascerated fruit was distilled In an acid medium, the distillate was extracted with cyclohexane, and biphenyl was determined In the extract using various measures obtained by first and second derivative Infrared (IR) spectrophotometry. Calculations were performed by PE680 and SNGLE programs on data obtained using a Perkln- Elmer Model 3600 data station. The relative precision of the determinations at 70 ppm was 1.8 to 2.0%; the detection limit was 5 ppm In all measurements, and recovery of spiking concentrations of 20 to 80 ppm ranged from 90.2 ± 5.5 % (for the amplitude of the 739 cm-1 peak of the first derivative) to 97.5 db 2.0% (for the trough-to-peak difference from the 737 cm-1 minimum to the 743 cm-1 maximum of the second derivative).
Determination of Methyl Nonyl Ketone by Liquid Chromatography
Authors: Bushway Rodney J
Published: February 2020

A liquid chromatographic (LC) method has been developed to determine methyl nonyl ketone, a dog and cat repellent, In formulations. Corn cob formulations were extracted In acetonltrlle for 1 min using a Polytron mixer; liquid formulations were diluted with acetonitrile. A 10 juL aliquot was Injected Into a Vydac 218 TP54 column, monitored at 280 nm. The mobile phase was acetonitrlle-methanol-water-lsopropanol (225 + 200 + 50 + 25). Total analysis time was 5 min. Six different solid formulations and 5 different liquid formulations were analyzed 6 times with all percent coefficients of variation (% CV) below 4. Purity of each methyl nonyl ketone chromatographic peak was checked using a photodlode array detector In peak purity mode. No Interferences were observed at 280 nm.
Liquid Chromatographic Method for Determination of Technical Deltamethrin and Deltamethrin in Pesticide Formulations: CIPAC Collaborative Study
Authors: Hanks Alan R
Published: February 2020

A liquid chromatographic method for determination of deltamethrin In 6 different technical and formulated products was collaboratively studied In 14 laboratories. Each sample Is dissolved In lsooctane-1,4-dloxane (80 + 20), separated by LC on a silica gel column (cyano column for ultra low volume formulation), and detected at 254 nm (230 nm for ≤0.5% powder formulations). Quantitation Is done by peak area measurements. Relative standard deviations for repeatability and reproducibility ranged from 0.56 to 1.00% and from 0.76 to 2.90%, respectively. The method has been approved Interim official first action by AOAC as a CIPAC-AOAC method.
Development of Milk Powder Reference Materials BCR-CRM 187,188. Part II. Certification
Authors: Griepink Bernard , Quirijns Jan K , Van Der Paauw Kees G , Mulders Ed J
Published: February 2020

Certification of the content of organochiorlne pesticides and their metabolites (OCPs) In 2 milk powders Is described. The OCPs are: hexachlorobenzene, HCH-lsomers (α-HCH, β- HCH, and γ-HCH), β-heptachlor epoxide, dleidrln, endrln, p,p'-DDE, and p.p'-DDT. CRM 187 Is a natural milk powder with low levels of OCPs (1.5 to 6.6 μg/kg); CRM 188 Is a spiked milk powder with levels up to 70 μg/kg on a dry weight basis. Particular emphasis is placed on the independence of the measurements done by 21 participants, the control of errors, and the statistical evaluation.
Survey of Total and Bioavailable Chromium in Grain and Cereal Products by Atomic Absorption Spectrophotometry
Authors: Plessi Maria , Monzani Agar
Published: February 2020

The chromium content of samples of cereals, legumes, oil seeds, and alimentary pastes (In the latter, bioavailable chromium as well) was determined by atomic absorption spectrophotometry. The chromium content in whole cereals differs substantially and Is mostly concentrated In pericarps. Variations occur not only among different types of cereals, but also among cereals of the same type, depending on the areas of origin. Concentration varies substantially even In samples of legumes and oil seeds. The content of bioavailable chromium (ethanol-extractable) Is, In most cases, more than 50% of the total chromium amount. This makes these products particularly Interesting as dietary supplements
Reaction to a Paper by Whitaker and Dickens on Aflatoxin Testing Plans for Shelled Peanuts in the U.S. and the Export Market
Authors: De Koe Willem J , Defize Peter R
Published: February 2020

The present paper examines a technical paper of Whitaker and Dickens on aflatoxin testing plans that discusses (without a literature reference) a testing plan used In The Netherlands. However, this testing plan has never been in operation. We present the current situation In The Netherlands with respect to legislation and sampling plans on aflatoxin, which has fairly Important consequences for the results of the simulation study of Whitaker and Dickens. It Is shown that the percentage of rejected U.S.-exported lots In The Netherlands would Increase from 16% to 27% based on the actual testing plan In The Netherlands. The need for International harmonization of testing, and the role of Codex Allmentarlus is also emphasized
Rapid Determination of Cholesterol in Selected Frozen Foods
Authors: Al-Hasani Sami M , Shabany Hossein , Hlavac Jan
Published: February 2020

A rapid method for determination of cholesterol in frozen foods has been developed. Direct saponification of the sample with alchoholic KOH was found to be faster, more economical, and less of a health hazard than the official AOAC method. Using direct saponification, the average recovery of cholesterol from spiked samples was 100.2%. When correlated with the AOAC method, the correlation coefficient was 0.9996. In addition, this method allows for analysis of 20 samples/day Instead of 8 samples/day by the AOAC method
Enzyme Immunoassay For Screening Of Sulfathiazole In Honey
Authors: Sheth Hasmukh B , sporns Peter
Published: February 2020

A simple enzyme Immunoassay (EIA) was developed to screen honey samples for sulfathiazole (ST) adulteration. Honey samples required only a 30-fold dilution before use In the procedure. Because 96 well microtlter plates were used and only 100 μL of diluted honey sample was required per well, numerous replicates or samples could be tested simultaneously. The EIA was able to detect at least 0.3 ppm levels of ST In honey and also provide a rough quantitation of ST amounts.
Liquid Chromatographic Determination of Clobetasone-17-Butyrate in Ointments
Authors: Patel Ajay G , Patel Ramanbhai B , Patel Mukeshbhai R
Published: February 2020

A liquid chromatographic (LC) method has been developed for determination of clobetasone-17-butyrate In ointment using clobetasone propionate as an internal standard. Separation was carried out on a C18 reverse-phase column using water-methanol as a mobile phase. Methylparaben and propylparaben (both sodium salt) used as preservatives did not Interfere with separation. Compounds are detected photometrically at 235 nm. Mean assay results for 0.05% commercial ointments were 100.36% (n = 5). Mean recovery of clobetasone-17-butyrate added to commercial ointment was 99.89%.
Analysis of Zearalenone and a-Zearalenol in Urine of Ruminants Using Gas Chromatography-Tandem Mass Spectrometry
Authors: Plasencia Javier , Mirocha Chester J , Pawlosky Robert J , Smith John F
Published: February 2020

The present paper describes a sensitive procedure for quantitative analysis of the Fusarlum mycotoxins zearalenone and α-zearalenol in urine of ruminants. Extraction is done with an octadecyl (C18) column and cleanup with a silica column providing a preparation that Is analyzed by gas chromatography- tandem mass spectrometry (GC-MS/MS). The trlmethylsllyl ether derivatives of zearalenone and a-zearalenol yield molecular ions with m/z 462 and 536, respectively. These Ions are selected In the first mass analyzer and then fragmented In a collision cell to give characteristic daughter Ions (m/z 151, 333, 318, and 446). The method is known as multiple reaction monitoring (MRM). Elimination of chemical background noise by selecting proper fragment ions produces chromatograms in which Identification and quantitation in a biological matrix is possible. The method was tested with sheep urine from an experimental feeding trial and was used to confirm natural mycotoxlcosis of cows affected with zearalenone. Zearalenone (1 ppb) and a-zearalenol (14 ppb) were found In 2 different cow urine samples. The detection limit for both zearalenone and zearalenol Is 1 ppb (1 ng/mL) In urine and Is linear between 1 and 20 ppb for the former and 1 and 10 ppb for the latter.
Determination of Phytic Acid in Cereals Using ICP-AES to Determine Phosphorus
Authors: Plaami Sirkka , Kumpulainen Jorma
Published: February 2020

A novel approach for determination of phytic acid in cereals has been applied In 2 traditional methods. In the first, phytic acid in a sample extract is first separated and concentrated by ion-exchange chromatography. The phytic acid concentrate is then quantitatively determined as phosphorus by Inductively coupled plasma atomic emission spectrometry (ICP-AES). In the second method, extracted phytic acid Is first precipitated by FeCI3 solution. The complexed iron is converted to ferric hydroxide by adding NaOH, thus releasing phytic acid as soluble sodium phytate. Phytate is then quantitatively determined as phosphorus by ICP-AES. In these methods, both the difficult acid digestion and the spectrometry determination of phosphorus found In traditional methods are eliminated by using ICP-AES. This results In a method that Is simpler, faster, and more accurate than earlier procedures.
Levels of Pesticide Residues in Egyptian Human Milk Samples and Infant Dietary Intake
Authors: Dogheim Salwa M , EL-Shafeey Mohamed , Afifi Abla M H , Abdel-Aleem Fatma E
Published: February 2020

Contamination of human milk with residues of organochlorlne pesticides and polychlorlnated blphenyls was studied In a series of Investigations concerned with the monitoring of these chemicals In Egyptian food. The DDT complex was the most frequently found pesticide, followed by total hexachlorocyclohexane Isomers. Heptachlor and its epoxide, dleldrln, hexachlorobenzene, and oxychlordane were also found but less frequently. Estimated dietary Intakes (EDIs) of these contaminants by the breast-fed Infants were compared to acceptable dally Intakes (ADIs). EDIs of DDT complex, lindane (gamma-HCH), heptachlor + heptachlor epoxide, and oxychlordane were below ADIs. Dleldrln EDI exceeded the acceptable daily intake.
Food and Drug Administration Pesticide Residue Monitoring of Foods: 1978-1982
Authors: Yess Norma J , Houston Marcia G , Gunderson Ellis L
Published: February 2020

Pesticide residues In foods are reported for the 5-year period 1978-1982 [fiscal years (FY) 78-82]. Results were compiled from the 2 complementary elements that comprise the Food and Drug Administration's (FDA) program for monitoring pesticide residues In foods. Under regulatory monitoring, which focuses on residues in raw agricultural commodities, a total of 49 877 samples (30 361 domestic and 19 516 Import) that Included fresh fruits and vegetables, grains, milk and dairy products, seafoods, and a variety of processed foods were analyzed. No residues were found in about 55 and 44% of the domestic and Import samples, respectively. About 3% of the domestic and 7% of the import samples were classed as violative. Data from the Total Diet Study, which Is conducted to determine dietary Intakes of a variety of chemicals, showed that residues of 42 pesticides were found in 1044 composites of table-ready foods. Results of FDA's monitoring for FY78-82 demonstrate that pesticide residue levels in the U.S. food supply were generally well below regulatory limits, and dietary Intakes were manyfold lower than the Acceptable Dally Intakes established by International agencies.
Capillary Column Gas Chromatography with Nitrogen-Phosphorus Detection for Determination of Nitrogen- and Phosphorus-Containing Pesticides in Finished Drinking Waters: Collaborative Study
Authors: Edgell Kenneth W , Jenkins Elizabeth L , Lopez-Avila Viorica , Longbottom James E
Published: February 2020

A joint U.S. Environmental Protection Agency/AOAC interlaboratory method validation study was conducted on EPA Method 507, Determination of Nitrogen- and Phosphorus- Containing Pesticides In Finished Drinking Water by Gas Chromatography with a Nitrogen-Phosphorus Detector, to determine the mean recovery and precision for analyses of 45 nitrogen- or phosphorus-containing pesticides in reagent water and finished drinking waters. The study design was based on Youden's nonreplicate plan for collaborative tests of analytical methods. The waters were spiked with 45 nitrogen- or phosphorus-containing pesticides at 6 concentration levels, prepared as 3 Youden pairs. Ten volunteer laboratories extracted the spiked test waters with methylene chloride, performed a solvent exchange with methyl ferf-butyl ether, and analyzed an aliquot of each extract by gas chromatography using a nitrogen-phosphorus detector. Results were analyzed using an EPA computer program, which measured recovery and precision for each of the 45 pesticides and compared the performance of the method between water types. Method 507 was judged acceptable for all analytes tested except merphos, which thermally decomposed in the Injection port of the gas chromatograph. Five compounds (carboxin, disulfoton, metolachlor, pronamlde, and slmazlne) exhibited statistically significant matrix effects for the finished drinking water. The method has been adopted official first action by AOAC.
Detection of Orange Juice Adulteration with Beet Medium Invert Sugar Using Anion-Exchange Liquid Chromatography with Pulsed Amperometric Detection
Authors: Swallow Kevin W , Low Nicholas H , Petrus Donald R
Published: February 2020

Carbohydrate analysis of 5 beet medium Invert sugar (BMIS) samples and 10 pure orange Juices was carried out using anion-exchange chromatography with a pulsed amperometric detector. This analysis revealed the presence of several oligosaccharides In BMIS that were in either low concentration or nonexistent in the orange juice samples. These oligosaccharides may be naturally present In sugar beets or synthesized during the acid and/or enzyme catalyzed hydrolysis of sucrose during the production of BMIS. BMIS was intentionally added to pure orange juice at levels of 5,10,15, and 20%. Subsequent liquid chromatographic (LC) analysis of these Intentionally adulterated samples revealed that detection of 5% BMIS In orange juice was possible.
Development of a Rapid Equine Serological Test (REST) by Modified Agar-Gel Immunodiffusion
Authors: Cutrufelli Mark E , Mageau Richard P , Schwab Bernard , Johnston Ralph W
Published: February 2020

A rapid equine serological test (REST) has been developed for detection of horse meat In a wide variety of raw meat products. The test Is an adaptation of previously developed field screening Immunodiffusion tests for beef, poultry, pork, and sheep detection. Results show that the REST test was specific, sensitive, and accurate in the analysis of 101 samples.
State Findings on Pesticide Residues in Foods—1988 and 1989
Authors: Minyard James P , Roberts Edward W
Published: February 2020

Findings of pesticide and related chemical residues are presented for 27 065 samples of foods collected and analyzed in 10 state food laboratories over 1988 and 1989 (fiscal years (FY) 88 and 89). These laboratories conduct food regulatory programs compatible with national programs of the U.S. Food and Drug Administration. Of the findings, 6325 samples contained detectable levels of 1 or more pesticide analytes and 418 (or 1.5%) of the total number of samples were deemed to be of regulatory significance
Determination of Monocyclic and Polycyclic Aromatic Hydrocarbons in Fish Tissue
Authors: Lebo Jon A , Zajicek Jim L , Schwartz Ted R , Smith Lawrence M , Beasley Mary P
Published: February 2020

An analytical method is presented in which fish tissue is analyzed for neutral monocyclic and polycyclic aromatic hydrocarbons (AHs) and aromatic sulfur heterocycles (ASHs) by capillary column gas chromatography (CGC) with photoionization detection. The sample enrichment procedure includes saponification with aqueous KOH, acidification of the digestates, and extraction of the aromatic compounds into cyclopentane-dichloromethane. Adsorption chromatography on tandem segments of potassium silicate and silica gel removes 99% of the coextracted lipid. Final enrichment by gel permeation chromatography eliminates residual biogenic material and potentially interfering alkanes. Relatively volatile monoaromatlcs are included among the analytes by virtue of the efficiency of the complementary enrichment steps, the use of small quantities of only low-boiling solvents, and the selectivity of the detector. Most targeted compounds (AHs ranging in size from C3-alkylbenzenes through benzo[ g,h,i]perylene and ASHs within the same size range) can be determined in 5 g (wet weight) samples of fish tissue at concentrations as low as 20 ng/g. Comparisons are made of recoveries of selected AHs under ordinary and gold fluorescent lighting conditions.
Determination of Oxyfluorfen Herbicide and Oxyfluorfen Amine Residues in Garbanzo Beans by Liquid Chromatography
Authors: Zhou Min , Miles Carl J
Published: February 2020

Oxyfluorfen and oxyfluorfen amine were determined by liquid chromatography (LC) with ultraviolet (UV) and photoconductivity detection (PCD). A simple extraction procedure acceptably recovered both analytes from garbanzo beans over a wide range of fortifications (0.05 to 20 ppm) (83 ± 4 for oxyfluorfen; 85 ± 4 for oxyfluorfen amine). Percent recoveries decreased slightly as the fortification level decreased. Both analytes could be determined simultaneously at a concentration >0.2 ppm In garbanzo beans. Detection limits were 3 ng for oxyfluorfen and 100 ng for oxyfluorfen amine using LC/UV, and 12 ng for both oxyfluorfen and oxyfluorfen amine with LC/PCD. Different knitted reaction coils and photoreactors were evaluated. Photoproduct yields and Identification were determined by ion chromatography. The LC/PCD method measures oxyfluorfen and oxyfluorfen amine separately and has a shorter analysis time, while the standard method using gas chromatography measures total residues and is more sensitive.
Comparison of the TRAACS 800 with AOAC Methods for Calcium and Phosphorus in Feeds
Authors: Orcutt Anne , Kane Peter , Imboden Sandra
Published: February 2020

Existing automated methods for calcium and phosphorus In animal feeds have been upgraded to permit determination of protein, calcium, and phosphorus simultaneously from a single sample solution running on a new generation of automated instruments. Minor changes and improvements in chemistry are described, and results using the new method are compared to results using AOAC official atomic absorption (calcium) and gravimetric (phosphorus) methods. For calcium, Mests showed no significant difference at the P ≤ 0.01 level over a range of concentration levels from 0-25%. For phosphorus, Mests showed no significant difference at the P ≤ 0.01 level over concentration ranges of 0 - 2% and 2 - 6%. Significant differences did exist at a concentration range of 6-18%. The small existing bias In these ranges was shown to be due to irregularities In the phosphorus standard curve fit, caused by protein and/or calcium components in the combined standard solutions.
Enhanced Supercritical Fluid Carbon Dioxide Extraction of Pesticides from Foods using Pelletized Diatomaceous Earth
Authors: Hopper Marvin L , King Jerry W
Published: February 2020

Supercritical fluid carbon dioxide (SC-C02), when used with an extraction enhancer, comprises a supercritical fluid extraction (SFE) system for extraction of pesticides and matrix components from fatty and nonfatty foods. After being mixed with the enhancer, samples ranging from 95 % water to pure lipophilic oils can be extracted efficiently with SC-C02. This extraction technique yields analyte recoveries in excess of 85 % for over 30 types of pesticides at incurred levels ranging from 0.005 to 2 ppm in such diverse matrixes as carrots, lettuce, peanut butter, hamburger, and fortified butter fat and fortified potatoes. SC-C02 provides a solvent medium that is nontoxic, nonflammable, and inexpensive while also eliminating the use and disposal of potentially carcinogenic organic solvents.
Quantitative Determination of Amines in Wine by Liquid Chromatography
Authors: Ibe Akihiro , Saito Kazuo , Nakazato Mitsuo , Kikuchi Yoko , Fujinuma Kenji , Nishima Taichiro
Published: February 2020

A liquid chromatographic (LC) procedure is described for the determination by dansylation of the following 16 kinds of biogenic amines found In wine: monomethylamine (MM), ethylamine (EM), iso- and n-propylamlne (Pr), iso- and n-butylamine (Bu), iso- and n-amylamlne (Am), pyrrolidine (PY), 2- phenethylamine (PH), tryptamine (TR), putresclne (PU), cadaverine (CA), histamine (HI), tyramine (TY), and spermidine (SP). The amines In white and red wine were applied to a column of Amberllte CG-50 type I resin (Na-form) after the column had been washed with water and eluted with 1N hydrochloric acid. This eluate was evaporated to dryness under reduced pressure and derivatized with dansyl chloride (DNS). LC separations were performed on Finepak SIL C18S and LiChrosorb RP-8 columns with an acetonitrile-water elution gradient. In the survey of commercial wines by this method, most of the samples were found to contain 12 amines, including iso-Am, CA, PU, TY, and others. The highest levels of these amines were 4.84 μg PU/mL in red wine, and 5.11 μg Iso-Am/mL in white wine. The total levels of amines in red wine were comparatively higher than in white wine.
Bacillus cereus
Authors: Jackson Susan G
Published: February 2020

Bacillus cereus is an environmentally ubiquitous, Grampositive, spore-forming bacillus responsible for 2 distinct foodborne disease syndromes as well as other manifestations of pathogenicity. The rapid-onset, "emetic," foodborne-disease syndrome is associated with an emetic toxin; the delayed-onset, "diarrheal" syndrome is associated with elaboration of enterotoxin. The majority of methods for detection of these toxins have relied on In vivo testing. More recent work on purification of enterotoxin facilitated the development of a rapid, specific, fluorescent Immunodot assay and a tissue culture screening assay for enterotoxin. Work on characterization and detection of emetic toxin is ongoing
Modifications to the Official Method for Testing Chlortetracycline HC1 in Animal Feeds
Authors: Hasselberger Mary Lee
Published: February 2020

Results are compared for the microbiological analysis of chlortetracycline using the AOAC method and a modified method applicable to potencies above 50 g/ton. Two modifications are presented: substitution of a pH range of 4.0-4.5 instead of the specified pH of 4.5 for the plating solution, and substitution of extraction by shaking instead of the blending procedure. There were no significant differences in results between the AOAC method and the modified method
Single-Laboratory Evaluation of Method 8060 for the Determination of Phthalates in Environmental Samples
Authors: Avila Viorica Lopez , Milanes June , Beckert Werner F
Published: February 2020

Method 8060 of the SW-846 methods manual for the determination of phthalates In aqueous and solid matrixes was modified and evaluated in a single laboratory. The range of compounds of interest was expanded to 16 phthalates. The results of a study to determine the extent and the sources of phthalate contamination in the laboratory and ways to minimize background contamination, conducted as part of this work, were reported elsewhere. The packed columns specified in Method 8060 for the gas chromatographic analysis were replaced with 2 fused-silica open-tubular columns of dissimilar stationary phases. These columns were connected to an inlet splitter and 2 electron capture detectors; this dual-column/ dual-detector setup allowed the primary and confirmatory analyses to be conducted simultaneously. Extracts were cleaned up by column chromatography on 10 g Florisil or alumina. Of the 16 target compounds, only 13 were recovered from the Florisil column (Method 3620), but all 16 were recovered from the alumina column (Method 3610). The use of commercially available Florisil and alumina solid-phase extraction cartridges for sample extract cleanup was evaluated, and a method that uses such cartridges (Florisil or alumina) was developed. This latter method gave quantitative recoveries for all 16 compounds. The effects of interferences represented by corn oil, dlesel hydrocarbons, and elemental sulfur were evaluated, and an internal standard and 3 surrogate compounds were identified and proposed for use with this method. The revised method was tested with samples of an estuarine water, a leachate, a groundwater, an estuarine sediment, a municipal sludge, and a sandy loam soil, each spiked with the 16 phthalates. For the aqueous samples spiked at 20 and 60 μg/L, the method accuracy ranged from 60 to 117% and method precision was better than 28%. The method accuracy and precision for solid samples extracted by Method 3550 were highly dependent on matrix type and on analyte concentration.
Microwave Acid Digestion of Various Food Matrixes for Nutrient Determination by Atomic Absorption Spectrophotometry
Authors: Oles Philip J , Graham Wanda M
Published: February 2020

Food matrixes were digested by treatment with nitric acidsulfuric acid-hydrogen peroxide mixtures and heating with a commercially available microwave apparatus. The digests were analyzed for sodium, potassium, magnesium, iron, calcium, zinc, copper, and manganese content by flame atomic absorption spectrophotometry. A total of 3 digestion programs were adopted for a variety of food matrixes. Microwave digestion times of 30-45 mln were normally sufficient for obtaining clear digests compared to hot plate digestion times of 8-12 h. Precision for microwave digestion of most nutrients was equal to or better than that of hot plate digestion. Microwave digestion gave comparable results for the nutrient elements. National Institute of Standards and Technology reference materials were analyzed for nutrient content after microwave digestion and the results compared favorably with the certified values. A laboratory breakfast cereal control sample with a history of over 20 separate hot plate digestions was prepared using the microwave technique. Results for the 8 elements were within ±7% of the hot plate digestion values. Predlgestlon spikes were recovered from several food matrixes with no effects resulting from Incomplete digestion of samples.
Gas Chromatographic Determination of Captan, Folpet, and Captafol Residues in Tomatoes, Cucumbers, and Apples Using a Wide-Bore Capillary Column:
Interlaboratory Study
Authors: Gilvydis Dalia M , Walters Stephen M
Published: February 2020

An interlaboratory study of the determination of captan, folpet, and captafol in tomatoes, cucumbers, and apples was conducted by 4 laboratories using wide-bore capillary column gas chromatography with electron capture detection. The 3 fungicides were determined using the Luke et al. multlresidue method modified to Include additional solvent elutlon in the optional Florisll column cleanup step used with this method. The crops were fortified with each fungicide at 3 levels per crop. Mean recoveries ranged from 86.2% for a 25.1 ppm level of captan in apples to 115.4% for a 0.288 ppm level of captafol In apples. Interlaboratory coefficients of variation ranged from 3.4% (24.7 ppm folpet) to 9.7% (0.243 ppm captafol) for tomatoes; from 2.8% (2.0 ppm captafol) to 8.2% (24.8 ppm captan) for cucumbers; and from 1.5% (0.234 ppm folpet) to 22.1% (0.266 ppm captafol) for apples.
Residue Analysis of Glyphosate and Its Principal Metabolite in Certain Cereals, Oilseeds,and Pulses by Liquid Chromatography and Postcolumn Fluorescence Detection
Authors: Wigfield Yuk Y , Lanouette Monique
Published: February 2020

A postcolumn liquid chromatographic method to determine the extractable residues of glyphosate (GLYPH) and its principal metabolite, (amlnomethyQphosphonic acid (AMPA), In various cereals and beans Is described. The finely ground sample Is extracted with a mixture of chloroform and water, and the resulting aqueous layer is passed through a cation exchange column. The eluate is adjusted to pH 7-10 and passed through an anion exchange column. The second column is eluted with 0.3M HCI solution and the resulting acidic eluate Is analyzed with liquid chromatography coupled with postcolumn fluorescence detection. The mean recoveries for GLYPH In barley, canola, dry pea, flax, soybean, wheat, and white bean ranged from 90.9 to 98.1%, with coefficients of variation (CV) from 2.9 to 10.0% and limits of detection (LOD) from 0.07 to 0.14 ppm. Similarly, mean recoveries for AMPA in the same crops ranged from 87.4 to 98.9%, with CV from 4.6 to 7.7% and LOD from 0.05 to 0.12 ppm. Using this method, an analyst can routinely analyze 6 samples per 1.5 days. The advantages of this procedure are discussed
Time Required to Achieve Homogeneity of Test Substances Added to Dog Feed
Authors: Sapienza Philip P , Ikeda George J , Warr Patricia I , Albert Richard H
Published: February 2020

The homogeneity of test substances in a carrier (animal feed) is a critical factor In conducting long-term feeding studies in laboratory animals. A method for determining the adequate amount of mixing to achieve homogeneity by a mixer of the type described has been determined when 2 distinctly different compounds are added to ground dog feed. Nicotinic acid and butylated hydroxyanlsole at a concentration of 1% were separately mixed with the dog feed for 15,30,45,60, and 120 min to determine optimum mixing time. Test portions were taken from 4 different sampling sites at each time period and analyzed in duplicate for the added substance. Four batches were prepared and the results were aggregated. Very little interbatch variability was observed. The variance of the average values from the 4 sampling sites at each time period was calculated and used as a simple, crude, but effective numerical quantity to monitor the approach to homogeneity of the mixture.
Validation of Methods Used in the Florida Department of Agriculture and Consumer Services' Chemical Residue Laboratory
Authors: Parker Gail Abbott
Published: February 2020

Very few methods for detecting residues of pesticides in food or agricultural samples have undergone rigorous collaborative study and possess official AOAC status. The Chemical Residue Laboratory has formalized a method validation scheme to use when incorporating or developing new, unofficial methods. These methods are validated by assessing certain performance parameters: scope, specificity, linear range, accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ). For accuracy and precision assessment, 12 replicate fortifications must yield recoveries within the range of 70-120% with a coefficient of variation (CV) that compares favorably to the Horwitz CV. LOD and LOQ are equivalent to 3 and 10 times, respectively, the background signal contributed by a sample matrix blank. This criterion that we use for LOD/LOQ is not universal. In fact, because of differing definitions, we have encountered difficulties in enforcing a tolerance by using a registrant's method. This paper also presents an example of our method validation scheme, using a recent method development project for detecting sulfamethazine in raw milk. The sulfamethazine project also revealed unanticipated personnel problems, underscoring the importance of the human factor in quality assurance.
Optimization of Sample Introduction Parameters for Determinations of Pesticides by
Capillary Gas Chromatography Using a Two Column, Two Detector System
Authors: Penton Zeldae E
Published: February 2020

A study was undertaken to determine if another injection mode could be substituted for splitless Injection in the trace analysis of pesticide samples. This technique often leads to problems such as carryover, poor repeatability, and breakdown of labile pesticides. Two capillary injectors were compared: a hot splitless injector and a temperature- programmable Injector, in which the sample is introduced into a glass insert under nonvaporizing conditions. With each injector, 2 columns of different polarity were Installed and a test sample containing a variety of pesticides was split between the 2 columns immediately after introduction. The effects of changing parameters such as Injector temperature, injection speed, method of installation of the 2 columns, and method of filling the syringe were examined for splitless injection. K was concluded that optimization is more difficult with splitless injection. Additionally, a comparison of precision and discrimination data demonstrated superior performance with the nonvaporizlng temperature-programmable Injector.
General Method for Determination of Pesticides in Soil Samples from Pesticide Mixer/Loader Sites
Authors: Taylor Sue G
Published: February 2020

A method was developed using gas and liquid chromatography (GC and LC) for the general pesticide screening of soil samples from mixer/loader sites. Samples were extracted in methanol-acetone in a sonicator and concentrated before analysis. Capillary GC with flame ionization detection and LC-dlode array were used for the screening of the soil extracts. Chromatograms were compared to standard tables for possible matches, and spectral confirmation was achieved In every case before a finding was reported as a contaminant. Also, the confirmed contaminations were quantltated on at least 2 weighings of the sample with at least 2 separate standards. Spike recoveries were performed for all soils found to contain a pesticide contaminant to determine the effect of the soil matrix on the extraction of the pesticide. Spike recovery and reproducibility data suggest that the method can be used effectively to determine pesticide contaminants in soil samples. The proposed method is a general method for screening many types of soils for many kinds of pesticides
Degradation of Organophosphorus Pesticides in Coastal Water
Authors: Wang Tsen C , Hoffman Marisae.E
Published: February 2020

Organophosphorus pesticides, such as malathlon and parathlon, ars considered to be a relatively safe group of pesticide chemicals. Once pesticides ars deposited to the coastal water, they could undergo chemical, photochemical, and biological processes. This study was mads to determine the persistence and dsgradation of both malathlon and parathlon In the Indian River estuary, which is located along the east coast of Florida. Hydrogsn ion concentration, temperature, salinity, and microorganisms affected the persistence of both malathlon and parathlon in the Indian River estuary. Alkaline hydrolysis was ths most competitive pathway for malathlon degradation. Only slight biological and photolytical degradation of malathlon was observed. By contrast, biological interaction was the most significant pathway for parathlon degradation. Alkaline hydrolysis and sunlight photolysis were only secondary pathways In the degradation of parathlon. The half-lives for parathlon and malathlon In the Indian River water (24 ppt salinity; pH 8.16) were 7.84 and 1.65 days, respectively.