bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liquid Chromatographic Determination of β-Lactam Antibiotics in Milk: A Multiresidue Approach
Authors: Moats William A , Harik-Khan Raida 
Published: February 2020

Abstract
In the United States, testing of all milk for residues of β-lactam antibiotics is now mandatory. Although a number of screening tests for determination of β-lactam antibiotic residues have been proposed, few reference methods of the required sensitivity (&lt;10 ppb) are available. Methods for determination of several β-lactam antibiotics using an automated liquid chromatography (LC) cleanup have been described recently. This paper describes the integration of these methods into a single extraction and cleanup procedure. Milk was deproteinized with 0.2M Et4NCI and acetonitrile. The resulting filtrate was evaporated to about 1 mL, made to 4 mL, and filtered through a disposable filter cartridge. For cleanup, 2 mL filtrate was loaded onto a bonded C18 LC column in 0.01 M KH2PO4 (A) and eluted with an acetonitrile (B) gradient using a program of 100 A:0 B (0–3 min) to 60 A:40 B (30 min). The β-lactams were concentrated into narrow bands and separated from each other. A fraction corresponding to each compound of interest was collected and rechromatographed for analysis. The procedure has been applied successfully to determination of ampicillin, amoxicillin, cephapirin, penicillin G, penicillin V, ceftiofur, and cloxacillin. In principle it can be applied to the determination of any β-lactam antibiotic or metabolite thereof by collecting the appropriate fractions.
Modified Immunodiffusion Method for Detection of Salmonella in Raw Flesh and Highly Contaminated Foods: Collaborative Study
Authors: Warburton Donald W , Feldsine Philip T , Falbo-Nelson Maria T , Ackerl J , Adamik D , Aldenrath S , Allain P , Arling V , Beaton L , Bowen B , Brocklehurst F , Catherwood K , Cavadini J , Coignaud C , Cooper A , Coulter R , Davis T , Douey D , Downey W , Drummond J , Durzi S , Dzogan S , Foster R , Fox C , Gibson E , Gour L , Gover G , Gray M , Heidebrecht P , Kerwood J , Krohn G , Kupskay B , LaFreniere D , Massicotte R , McDonagh S , Molleken B , Oggle J , Perlette M , Pugh P , Purvis U , Saint W , Trottier Y , Vinet J , West D , Wheeler B , Zebchuk A 
Published: February 2020

Abstract
A total of 19 government and private industry laboratories in Canada and the United States participated in the collaborative study. Naturally contaminated ground poultry and animal meals, as well as inoculated raw shrimp, were examined for presence of Salmonella by both the modified immunodiffusion method and the Bacteriological Analytical Manual culture method, resulting in an agreement rate of 93.1%. The 2 methods are statistically equivalent for all food types at each inoculation level and for all lots of naturally contaminated foods evaluated in this study. The modification of the AOAC Official Method 989.13, immunodiffusion (1–2 TEST) method for detection of motile Salmonella in all foods, has been adopted revised first action by AOAC INTERNATIONAL.
Liquid Chromatographic Determination of Atropine in Nerve Gas Antidotes and Other Dosage Forms
Authors: Lehr Gary J , Yuen Stella M , Lawrence Glen D 
Published: February 2020

Abstract
A simple and specific liquid chromatographic method was developed for the determination of atropine in nerve gas antidotes and several other dosage forms. The method is also used simultaneously to quantitate phenol, an antimicrobial agent present in nerve gas antidotes, and to monitor the level of tropic acid, a principal degradation product of atropine. The system uses a Spherisorb CN column and a mobile phase of acetonitrile–0.05M sodium phosphate monobasic (10 + 90), pH 4.0. The detection wavelength is 220 nm. The method was validated by testing for accuracy, linearity, reproducibility and precision. In addition, the proposed method was applied to 8 commercial preparations of atropine, including injectables, ophthalmic solutions, and ointments, and was found to be satisfactory and free from interferences from preservatives, such as benzyl alcohol, methylparaben, benzalkonium chloride and chlorobutanol, that are present in these formulations.
Determination of Sulfadimethoxine Withdrawal Time from Milk. Part I: Dosing, Sampling, and Assay
Authors: Weiss George , Laurencot Henry J , Macdonald Alexander , Duke Paul D , Misra Kabita , Horton Glyn M , Katz Stanley E , Brady Marietta Sue 
Published: February 2020

Abstract
This study was undertaken to determine whether present regulations for discarding milk from cows treated with sulfadimethoxine (SDM) can be supported by modern analytical methodology. Two groups of milking cows (10 in first group; 11 in the second) were treated orally with SDM at the recommended dose levels for 5 days. The SDM concentration in the milk was determined with 4 methods (Charm Inhibition Assay [CIA], Charm II, enzyme linked immunosorbent assay, and liquid chromatography) during the treatment and the subsequent withdrawal periods. The results of the 4 assays were compared.
Relative Effectiveness of Selenite Cystine Broth, Tetrathionate Broth, and Rappaport-Vassiliadis Medium for the Recovery of Salmonella from Raw Flesh and Other Highly Contaminated Foods: Precollaborative Study
Authors: June Geraldine A , Sherrod Patricia S , Hammack Thomas S , Amaguana R Miguel , Andrews Wallace H 
Published: February 2020

Abstract
The effectiveness of selenite cystine (SC) broth, tetrathionate (TT) broth, and Rappaport-Vassiliadis (RV) medium for recovery of Salmonella spp. from 8 highly contaminated foods was determined. RV medium prepared from individual ingredients and incubated at 42° and 43°C was compared with 2 commercial (Difco and Oxoid) media incubated at 42°C. Naturally and artificially contaminated foods were tested under 2 protocols. For Protocol 1, each food was preenriched in the appropriate medium. After incubation, serial 10 fold dilutions of the preenriched foods were inoculated into selective enrichment media and incubated at 35°, 42°, or 43°C. Effectiveness of these conditions was evaluated by most probable number determination of Salmonella spp. recovered. Productivity of selective enrichments did not differ significantly with this protocol, except that with Oxoid RV medium the number of Salmonella cells recovered from most of the foods was significantly reduced. For Protocol 2, twenty 25 g test portions from artificially inoculated foods were examined qualitatively for Salmonella spp. The effectiveness of the broth/temperature combinations was determined by the number of positive tests under each condition. RV medium prepared from individual ingredients and TT broth incubated at 43°C yielded significantly more Salmonella-positive tests from frog legs and lettuce than did SC and TT broths incubated at 35°C or commercial RV medium incubated at 42°C. With pork sausage and ground beef, significantly fewer Salmonella-positive tests were found with Oxoid RV medium incubated at 42°C and SC incubated at 35°C than from other selective enrichments. With chicken, fewer Salmonella-positive tests were found from SC and TT broths incubated at 35°C and Oxoid RV medium incubated at 42°C than from other selective enrichments. There were no significant differences among selective enrichments in the recovery of Salmonella spp. from the remaining foods. Overall, RV prepared from individual ingredients and incubated at 42°C yielded the highest number of Salmonella-posWive tests.
Liquid Chromatographic Method for Rapid Determination of Total Avermectin B1 and 8,9-Z-Avermectin B1 Residues in Apples
Authors: Cobin Janice A , Johnson Nelson A 
Published: February 2020

Abstract
A liquid chromatographic method has been developed and validated for the rapid determination of avermectin B1 and 8,9-Z-avermectin B1 residues in apples. The avermectins are extracted from the crop matrix with an acetonitrile–water–hexane mixture; the extract is cleaned up on an aminopropyl solid-phase extraction column. The avermectins are derivatized with trifluoroacetic anhydride and analyzed by reversed-phase liquid chromatography with fluorescence detection. Recoveries of avermectins from apples fortified with about 2–77 ppb avermectin B1a or 2-27 ppb 8,9-Z-avermectin B1a averaged 85%. The limit of quantitation is 2 ppb (signal- to-noise [S/N] ratio, 12) and the limit of detection is 1 ppb (S/N ratio, 6) for each analyte. The assay is a simple, rapid, and sensitive method for monitoring the total amount of avermectin residues in apples.
Extraction of Lipid-Soluble Marine Biotoxins
Authors: Hannah Donald J , Till Desmond G , Deverall Terry , Jones Paul D , Fry Joanne M 
Published: February 2020

Abstract
A recent extensive outbreak of toxic shellfish poisoning (TSP) in New Zealand, with at least 4 types of toxicities present, required the development of a new method for detecting lipid-soluble marine biotoxins. The complexity of studying this outbreak, requiring large sample numbers, dictated the development of a robust and safe method for extracting lipid-soluble toxins. The new method is based on extraction of lipophilic compounds with acetone followed by partitioning into dichloromethane. The dichloromethane extract is evaporated to constant weight and suspended in a detergent–saline solution for use in a mouse bioassay. The new method produces an extract of superior quality, is quicker and more sensitive compared with extraction methods currently used.
Four-Laboratory Validation Study of the Determination of Chloramphenicol in Veal Calf Urine
Authors: Holland Kathleen P , Henry A Carolyn , Wilson T Roger , Dreas S John , Ashworth B Raymond 
Published: February 2020

Abstract
A four-laboratory validation study of a method for the quantitation and confirmation of low part-perbillion levels of chloramphenicol extracted from veal calf urine was done. With this method, chloramphenicol, derivatized to the bis(trimethylsilyl) ether, was quantitated by gas chromatography with electron capture detection (GC–ECD) and confirmed by selected-ion monitoring in a negative ion chemical ionization gas chromatograph-mass spectrometer (GC–NICI–MS). Four analysts from 4 laboratories participated in the portion of the study devoted to chloramphenicol quantitation. Every analyst analyzed 5 sets, one set per day, on 5 different days. Each set included 6 samples consisting of a blank, 2 fortified samples, 2 incurred urine samples, and one duplicate. Thus, each analyst worked on a total of 30 samples. Chloramphenicol concentrations ranged from 0 to 9.7 ppb. All data were reported to 0.1 ppb. Coefficients of variation for distribution, CVd, ranged from 8.82 to 14.14% and for precision, CVr, ranged from 9.15 to 14.80%. Three analysts from 3 laboratories also participated in the confirmatory portion of the study, which was carried out to test whether the NICI–MS method developed earlier for higher concentrations of chloramphenicol and for an extract of muscle tissue could be applied to lower levels of chloramphenicol and to an extract prepared from urine. The extracts of 10 of the 30 samples were designated for confirmation only, but were obtained by the same procedure as extracts used for the quantitation part of the study. The confirmation part of the study failed to determine whether NICI–MS is still valid for these levels and this matrix because source temperature lower than that recommended by the originating laboratory as used by all collaborating laboratories. The spectra generated by collaborators were different from those expected.
Determination of Boron in Fertilizers by Inductively Coupled Plasma-Atomic Emission Spectrometry: Studies of Some Spectral Interferences at Different Wavelengths
Authors: Matilainen Rose , Tummavuori Jouni 
Published: February 2020

Abstract
The most sensitive analytical wavelengths of boron cannot be used in the determination of boron in fertilizers by inductively coupled plasma-atomic emission spectrometry because of spectral interference by potassium, phosphorus, and iron. For the 4 wavelengths of boron investigated, it was noticed that, at the same wavelength, the pattern of spectral interference changes according to fertilizer composition. The spectral interference patterns at the 4 analytical boron wavelengths were studied by adding matrix elements typically found in fertilizers to real fertilizer samples. When levels of added matrix elements correlate less than 0.2 to each other, the effect of added matrix elements on boron determination can be calculated by multiple linear regression. The best analytical wavelength for determination of boron in fertilizer is 208.959 nm. If wavelength is selected only according to calibration data, without doing interference studies, the best wavelength should be 249.773 nm. Multiple linear regression in conjunction with experimental design may be used to determine the best analytical wavelength for a sample matrix under analysis, examine the interference elements, and verify the concentration detected.
Simultaneous Determination of Chlorothalonil and Hexachlorobenzene in Technical and Formulated Materials by Capillary Gas Chromatography
Authors: Vargyas Linda D , Walls Gregory E , Cryberg Richard L , Bramstedt William R , Wang Frank J , Mayo Hugh L , Eilrich Gary L 
Published: February 2020

Abstract
A capillary gas chromatographic method using flame ionization detection was developed for simultaneous assay of chlorothalonil and hexachlorobenzene in technical material and formulated products. Method precision is excellent, and the method allows simultaneous determination of one chemical impurity. The method uses an internal normalization reagent (n-butyl phthalate). Modification and extension of the method to formulated products, including wettable powders, water-based flowables, and dispersible (or dry flowable) granular formulations, are discussed. Preliminary statistical analysis of intra- and interlaboratory comparisons was performed to evaluate method ruggedness. Average relative standard deviations for technical materials were 0.34 and 0.17% from 2 laboratories. Additional method validation studies were conducted to examine the influence of pH, solvent systems, gas chromatographic systems, and temperature conditions on different formulations.
Liquid Chromatographic Fluorescence Method for Multiresidue Determination of Thiabendazole and 5-Hydroxythiabendazole in Milk
Authors: Arenas Rene V , Johnson Nelson A 
Published: February 2020

Abstract
A novel liquid chromatographic multiresidue method has been developed for quantitation of thiabendazole (TBZ), the metabolite 5-hydroxythiabendazole (5-OH-TBZ), and the sulfate conjugate of 5-hydroxythiabendazole (5-HSO4-TBZ) in raw cow’s milk. The 5-HSO4-TBZ is hydrolyzed quantitatively under acidic conditions to 5-OH-TBZ. TBZ and 5-OH-TBZ are extracted from milk at pH 8.0 with ethyl acetate followed by cleanup of the extract on a cation-exchange solid-phase extraction column. Analytes are quantitated by liquid chromatography with a cation-exchange stationary phase and fluorescence detection. Recoveries from raw cow’s milk samples fortified with TBZ and 5-OH-TBZ or TBZ and 5-HSO4-TBZ at 0.05 to 2 ppm ranged from 87 to 103% for TBZ, 98–109% for 5-OH-TBZ, and 96–115% for 5-HSO4-TBZ (quantitated as 5-OH-TBZ). The assay provides a simple, rapid, and sensitive multiresidue method for monitoring total residues of TBZ, 5-OH-TBZ, and 5-HSO4-TBZ in milk.
Liquid Chromatographic Determination of Tolrestat and Related Compounds in Raw Materials
Authors: Beaulieu Normand , Lacrok Pauline M , Sears Roger W , Loveremg Edward G 
Published: February 2020

Abstract
A liquid chromatographic method was developed for the determination of tolrestat and 7 related compounds. The lower limit of quantitation of the related compounds in the presence of the drug was &lt;0.05%. The coefficient of variation on the assay of drug raw material analyzed on 5 different days was 0.75%. Total impurities found in 2 samples of tolrestat from different sources were 0.12 and 0.54%, respectively. The method was validated by a second laboratory.
Relative Effectiveness of Selective Plating Agars for Recovery of Salmonella Species from Selected High-Moisture Foods
Authors: Sherrod Patricia S , Amaguana Rene Miguel , Andrews Wallace H , June Geraldine A , Hammack Thomas S 
Published: February 2020

Abstract
The relative effectiveness of 6 selective plating media were compared for effectiveness in recovery of Salmonella spp. from selected high-moisture foods. Three new plating agars (EF-18, Rambach, and xylose lysine Tergitol-4) and 3 selective plating agars (bismuth sulfite, Hektoen enteric, and xylose lysine desoxycholate) recommended by AOAC INTERNATIONAL and the Bacteriological Analytical Manual (BAM) were compared. The agars were streaked from cultures selectively enriched in selenite cystine broth, tetrathionate broth, and Rappaport–Vassiliadis medium. The high-moisture foods studied were naturally contaminated pork sausage, chicken parts, turkey parts, and frog legs and artificially contaminated shrimp, oysters, egg yolks, and lettuce. The relative effectiveness of each selective plating agar was determined by recovery of Salmonella spp. and enumeration of false-positive and false-negative reactions. Although the new selective plating agars compared favorably with the AOAC/BAM-recom mended agars, they offered no advantage. Incubation of selective enrichment broths at elevated temperatures decreased the numbers of false-positive and falsenegative reactions for all 6 selective plating agars.
Incidence of Aflatoxins in Animal Feedstuffs: A Decade’s Scenario in India
Authors: Dhavan A S , Choudary M R 
Published: February 2020

Abstract
During the period 1983–1993,4818 samples of agricultural commodities, comprising cereals, oilseed cakes, compound feeds, and other ingredients, were examined for aflatoxin contamination. High quantities of aflatoxins were found in groundnut cake, deoiled groundnut cake, maize, and mixed feeds. Highest incidence of aflatoxin contamination was observed in groundnut cake (96.35%) and deoiled groundnut cake (96.20%), and the highest level of aflatoxin B1, 8260 ppb, was observed in maize.
Determination of Amino Acids in Food and Feed by Derivatization with 6-Aminoquinolyl-N-Hydroxysuccinimidyl Carbamate and Reversed-Phase Liquid Chromatographic Separation
Authors: Liu Hong Ji , Chang Bi Ying , Yan Hui Wen , Yu Feng Hua , Liu Xing Xiang 
Published: February 2020

Abstract
A study of a new amino acid analysis method using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate as a precolumn derivatization reagent for the analysis of food and feed is described. All amino acids, including methionine sulfone and cysteic acid, were well separated on a liquid chromatographic system using the optimized chromatographic conditions. Salts in food and feed interfered very slightly with the derivatization yields of all amino acids. Several typical agricultural products and animal feeds, including 2 AOAC test samples, were analyzed with the method. The results agreed well with the data generated by using the classical postcolumn method with ion-exchange chromatography. The average relative standard deviations for corn and broiler starter feed were 0.74 and 0.70%, respectively. Good recoveries of all amino acids were demonstrated (average, 101%), even for a sample with a very complex matrix.
Supercritical Fluid Extraction of N-Nitrosamines in Hams Processed in Elastic Rubber Nettings
Authors: Pensabene John W , Fiddler Walter , Maxwell Robert J , Lightfield Alan R , Hampson James W 
Published: February 2020

Abstract
A method for analysing /V-nitrosamines in hams processed in elastic rubber nettings by supercritical fluid extraction (SFE) is described. The study was carried out with the prototype of a commercial extractor with a silica gel adsorption cartridge integrally attached to the variable restrictor. The SFE method was compared with a solid-phase extraction procedure currently used for ham analysis. Both methods used the same gas chromatographic–chemiluminescence detection conditions. No significant difference (p &lt;0.05) was found between results obtained with the 2 methods. Repeatability standard deviation of the SFE method was 1.7 ppb, with a coefficient of variation (CV) of 2.7%, compared with 2.2 ppb, with a CV of 3.5%, for solid-phase extraction. SFE permits minimal use of solvent and more rapid analysis of nitrosamines.
Determination of Free and Total Carbohydrate Profile in Soluble Coffee
Authors: Prodolliet Jacques , Bruelhart Milene , Lador Fabienne , Martinez Cristtna , Obert Ladislav , Blanc Maurice B , Parchet Jean-Michel 
Published: February 2020

Abstract
A liquid chromatographic (LC) method was evaluated for the determination of free and total carbohydrates in soluble coffee. Samples are solubilized in water for free carbohydrates or hydrolyzed with LOON hydrochloric acid for total carbohydrates. An aliquot of the sample solution is analyzed on a pellicular anion-exchange polystyrene–divinylbenzene column using pure water as the mobile phase. Carbohydrates are quantitated by a pulsed amperometric detector. All major carbohydrates found in soluble coffee are determined in a single run. The technique allowed the detection of fraudulent addition of coffee husks or parchments as well as cereals or caramelized sugar for the 63 commercial products analyzed. High levels of free mannitol, free fructose, free glucose, sucrose, total glucose, and total xylose are a good indication of adulteration. Data were compared with those obtained from separate enzymatic determinations and from a different LC procedure. A close agreement among the methods was observed. However, the original method was superior in precision and was the only procedure that enabled the quantitation of all major carbohydrates. The technique is, therefore, a very powerful tool for routine analysis and for purity assessment of soluble coffee.
Enzyme Immunoassay for Carminic Acid in Foods
Authors: Yoshida Ayako , Takagaki Yutaka , Nishimune Takahiro 
Published: February 2020

Abstract
A competitive enzyme immunoassay (EIA) for carminic acid was investigated. Monoclonal anti-carminic acid antibody was obtained from A/J mice immunized with carminic acid-human immunoglobulin G (IgG) conjugate. Carminic acid was extracted with distilled water from beverage, jelly, candy, pasta sauce, yogurt, or ice cream samples. Ham or fish paste samples were digested with pro-nase, then carminic acid was extracted from samples with sodium hydroxide solution. The extract was diluted more than 10-fold with 1% gelatin in borate buffer solution. Microtiter plates were coated with carminic acid-bovine serum albumin (BSA) conjugate or just BSA. Goat anti-mouse lgG(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 0.3–10 ng/mL, and the detection limit was 0.2 μg/g original sample. Recoveries of carminic acid by this assay were &gt;95% for milk beverage and jelly, and &gt;85% for yogurt and fish paste. Carminic acid was detected in 7 of 26 red-colored commercial food products and ranged from 3.5 to 356 μg/g. This EIA system also responded to the structural analogue of carminic acid, laccaic acid.
Determination of Hydramethylnon Residues in Grass by Liquid Chromatography with Confirmation by Liquid Chromatography/Mass Spectrometry
Authors: Stout Steven J , Peterson Robert P , Dacuhna Adrian R , Picard Gerald L 
Published: February 2020

Abstract
An improved method for determination of hydra-methylnon residues in pasture grass is described. The method uses (1) the hydrochloride salt of hy-dramethylnon to improve its water solubility and (2) an acid–methanol precipitation to remove chlorophylls while leaving the analyte in solution. The liquid chromatographic method has a validated sensitivity of 0.05 ppm with controls showing &lt;0.004 ppm. The overall average recovery from 0.05 to 0.50 ppm was 98%, with a standard deviation of 11%. Samples showing a positive response (0.05 ppm or higher) and requiring mass spectrometric confirmation are directly amenable to liquid chromatography/mass spectrometry without additional sample preparation.