bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aflatoxin Contamination in Foods and Foodstuffs in Tokyo: 1986-1990
Authors: Tabata Setsuko , Kamimura Hisashi , Ibe Akihiro , Hashimoto Hideki , Iida Mami , Tamura Yukihiro , Nishima Taichtro 
Published: February 2020

Abstract
Aflatoxins were determined in 3054 samples of foods or foodstuffs, including cereals, nuts, beans, spices, dairy products, dry fruits, and edible oil. Samples were collected in Tokyo from 1986 to 1990. Aflatoxins were found in rice products, adlay, corn, crude sugar, peanut products, pistachio nuts, brazil nuts, sesame products, butter beans, white pepper, red pepper, paprika, nutmeg, and mixed spices. The highest incidence of aflatoxin contamination was observed in nutmeg (80%), and the highest level of aflatoxin B1 was observed in pistachio nuts (1382 ppb).
Comparison of Liquid Chromatographic Method to AOAC Microbiological Method for Determination of L-Tryptophan in Tablets and Capsules
Authors: Kim Henry S , Angyal Gerald 
Published: February 2020

Abstract
A reversed-phase liquid chromatographic (LC) method coupled with precolumn derivatization of L-tryptophan with phenylisothiocyanate was compared to the AOAC microbiological method for determining L-tryptophan in tablets and capsules. For the microbiological method, the concentrations of L-tryptophan were 4-8% lower in autoclaved test samples (hot method) than in test samples that were not autoclaved (cold method). When L-tryptophan values obtained by the LC method were compared to those obtained by the cold microbiological method, no significant differences were observed (P &gt; 0.05). The mean relative standard deviations were 2.9% for the LC method and 1.6% for the cold microbiological method. The mean recoveries of standard L-tryptophan added before analysis were 99% for the LC method and 101 % for the cold microbiological method. These results demonstrate that both methods are reliable for determining free L-tryptophan contained in tablets and capsules. However, the LC method has the advantages of using a smaller test portion and having a shorter analysis time.
Calculation of Juice Content in a Diluted Fruit Juice Beverage
Authors: Lindsay Chester W 
Published: February 2020

Abstract
A1990 amendment to the Food, Drug and Cosmetic Act states that if a food purports to be a beverage containing vegetable or fruit juice, it shall be deemed to be misbranded unless its label bears a statement of the total percentage of such fruit or vegetable juice content. The intent of the present paper is to assist beverage manufacturers in calculating the juice content of their products for the purpose of a label declaration.
Small-Scale Survey of Organotin Compounds in Household Commodities
Authors: Yamada Sadaji , Fujii Yuko , Mikami Eiichi , Kawamura Norihisa , Hayakawa Junko , Aoki Kazuharu , Fukaya Megumu , Terao Chikahiro 
Published: February 2020

Abstract
Ninety-five commercially available items were analyzed for a small-scale survey of organotin compounds (OTCs) in household commodities such as textile products, shoe polish, adhesives, paint, and wax. Neither tributyltin nor triphenyltin species were found in any items; however, di- and trioctyltin and/or dibutyltin species (DOT, TOT, and DBT, respectively) were detected in 15 items; DOT was found in 14 items, TOT in 5 items, and DBT in 4 items. DOT was found in 2 diaper covers at about 0.1 %. Detection frequencies of OTC were 6/10 for diaper covers, 3/10 for bibs, 2/10 for sanitary panties, 1/5 for outergarments, 1/5 for stockings, 1/5 for socks, and 1/10 for shoe polish.
Extraction and Gas Chromatographic Screening of 14 Chlorinated Pesticides in Crayfish (Procambarus clarkii) Hepatopancreas
Authors: Lott Heidi M , Barker Steven A 
Published: February 2020

Abstract
A multiresidue isolation technique using matrix solid-phase dispersion (MSPD) and gas chromatography/ electron capture detection is applied to crayfish (Procambarus clarkii) hepatopancreas for the extraction and determination of 14 chlorinated pesticides (α-BHC, β-BHC, lindane, heptachlor, aldrin, heptachlorepoxide, p,p'-DDE, dieldrin, endrin, 4,4'- DDD, endrin aldehyde, p,p'-DDT, endosulfan sulfate, and methoxychlor). Pureed crayfish hepatopancreata (0.5 g aliquot) are fortified with the 14 pesticides and with δ-BHC as an internal standard before blending with 2 g C18 (octadecylsilyl)- derivatized silica. The C18-hepatopancreas matrix blend and 2 g activated Florisil comprise an extraction column from which the pesticides are eluted by adding 8 mL acetonitrile. Two microliters of the eluate is directly analyzed by gas chromatography with electron capture detection. Unfortified blank controls are treated similarly. The eluate contained all the pesticide analytes and was free of interfering coextractants at most fortification levels. Correlation coefficients for the 14 extracted pesticide standard curves (linear regression analysis) ranged from 0.9685 to 0.9985. Average relative percent recoveries (recoveries for all pesticides ranged from 55 ± 10.4% to 118 ± 45.2%, n = 15 for each pesticide) over the range of concentrations examined, interassay variability (7.1 ± 5.7% to 16.0 ± 5.6%, n = 15 for each pesticide), and intra-assay variability (0.0-26.2%, n = 5 for each pesticide) indicated that the MSPD methodology allowed for the successful extraction and determination of the 14 chlorinated pesticides at 125-2000 ng/g levels in crayfish hepatopancreas.
Total Organochlorine Content of Fish from the Great Lakes
Authors: Newsome W Harvey , Andrews Paul , Conacher Henry B S , Rao R R , Chatt A 
Published: February 2020

Abstract
Residues of polychlorinated biphenyls (PCBs) and organochlorine pesticides were determined in several species of commercial fish from the Great Lakes and compared to the total organic chlorine determined by neutron activation analysis. The mean organochlorine contents ranged from 44 to 138 ppm (lipid basis) and were 5 to 72 times higher than the contents of PCBs and organochlorine pesticides. Marine fish also contained a large proportion of unidentified organic chlorine. The unknown material in the Great Lakes fish was found to chromatograph with the high molecular weight lipid fraction by gel permeation chromatography.
Fast Atom Bombardment Mass Spectrometric Analysis of Base Hydrolyzed γ-Lactone
Authors: Baker Randall J 
Published: February 2020

Abstract
Fast atom bombardment (FAB) mass spectrometry (MS) is used to characterize the γ-hydroxy carboxylic acid (γ-HCa) formed from base hydrolyzed γ-lactone at room temperature. Acidification of this base hydrolyzed solution reconverts the γ-HCa back to γ-lactone. Mass shift differences between tetramethylammonium (TMA+) and Na+ ion-pairs with the anionic γ-HCarboxylate(–) (γ-HC(–)) are used to confirm molecular ion identifications. FAB ionization was required to provide mass characterization of the γ-HCa. Electron ionization (El) MS of the γ-HCa was unsuccessful and reconverted γ-HCa back to γ-lactone because of complete thermally induced dehydration. The present paper suggests structures for El fragmentation that support the molecular structure of γ-lactone.
Performance of Homogenizers in Infrared Milk Analyzers: A Survey
Authors: Smith Erika B , Barbano David M , Lynch Joanna M , Fleming J Richard 
Published: February 2020

Abstract
The objective of this survey was to determine if infrared milk analyzers can achieve a &lt;0.05% difference in fat test between unhomogenized and homogenized portions of the same milk, as stated in official methods. Two batches of pasteurized, unhomogenized milk (3 and 6% fat) were prepared from a single source of raw cream and skim. Homogenized milks were produced at 3 pressures: 0, 10342, and 17238 kPa. Pairs of unhomogenized and homogenized portions of the same milk were tested on 22 infrared analyzers. More instruments exceeded the 0.05% difference between homogenized and unhomogenized milk than expected; differences between homogenized and unhomogenized milk increased with increasing homogenization pressure and fat concentration. At 3% fat, differences between homogenized and unhomogenized milks at both 10342 and 17238 kPa were &lt;0.05% for 21 of 22 instruments for fat A; only 17 and 13 of 22 instruments for fat B achieved a difference of &lt;0.05% at 10342 and 17238 kPa, respectively. At 6% fat, differences between homogenized and unhomogenized milks for fat A were &lt;0.05% for 15 and 14 of 22 instruments at the 2 pressures, respectively. For fat B, 8 and 5 of 22 instruments achieved a difference of &lt;0.05% at 10432 and 17238 kPa. Instruments were also evaluated for homogenization efficiency by a revised criterion that is dependent on the fat content of the samples used for the evaluation.
Automation of Potentiometric Measurements: Determination of Water-Extractable Sodium in Bread Using a Sodium Ion Selective Electrode with Minimum Sample Preparation
Authors: Yperman Jan , Carleer Robert , Reggers Guy , Mullens Jules , Poucke Lucien Van 
Published: February 2020

Abstract
Different automated potentiometric procedures for the determination of NaCI in bread have been investigated and evaluated. The results are compared with data from atomic absorption spectrophotometry (AAS). A continuous potentiometric Na+ determination using a sodium ion selective electrode (ISE) is superior to all other methods. The sodium content can be measured by a reliable, rapid, and inexpensive potentiometric measurement of a finely ground and dried bread sample, extracted in the measurement beaker, as an alternative to the conventional and time-consuming AAS procedure.
Liquid Chromatographic Determination of Dicloxacillin Preparations: Interlaboratoiy Study
Authors: Hsu Mei-Chich , Huang Weng F 
Published: February 2020

Abstract
A previously published liquid chromatographic method proposed for the analysis of dicloxacillin preparations was subjected to an interlaboratory study. The method is rigorously defined in terms of performance requirements, yet allows a degree of flexibility to the individual analyst. Eight laboratories participated in a study to analyze 3 samples in duplicate. Estimates for the repeatability and reproducibility of the method, expressed as relative standard deviations of the results of the determination of dicloxacillin preparations, were &lt;0.57 and 2.56%, respectively.
Simultaneous Liquid Chromatographic Determination of Thiamine and Riboflavin in Selected Foods
Authors: Sims Art , Shoemaker Dirk 
Published: February 2020

Abstract
A reliable, improved liquid chromatographic (LC) method has been developed for the measurement of thiamine and riboflavin in foods. The major improvement in the method is the chromatographic separation achieved. The method is also very reproducible and extremely sensitive. After autoclave extraction, samples are derivatized to form thiochrome (a highly fluorescent oxidation product of thiamine). Riboflavin is naturally fluorescent. Interferences are removed on a Ci8 cartridge and chromatographed by using a reversed-phase separation. The mobile phase used is 72% 0.005M NH4OAc (pH 5.0)-28% MeOH. Fluorescence detection using wavelength switching, 370-435 for thiamine and 370-520 for riboflavin, allows determination of each vitamin at its optimum wavelength for maximum sensitivity. Detection limits were 0.05 ng for both thiamine and riboflavin. The method can also be performed by using a fluorescence detector at a single wavelength, but with a sacrifice of sensitivity. Data comparisons between AOAC fluorometric and LC results were excellent for routine samples, as well as for American Association of Cereal Chemists (AACC) check samples. All LC results from AACC samples were within 2 standard deviations of the mean. Reproducibility was 1.9% for thiamine and 1.6% for riboflavin.
Reversed-Phase Liquid Chromatographic Method for the Simultaneous Determination of Benomyl and Methyl lH-Benzimidazol-2-ylcarbamate in Wettable Powder Formulations
Authors: Singh Raj P , Chiba Mikio 
Published: February 2020

Abstract
A liquid chromatographic (LC) method is reported for the simultaneous determination of benomyl, methyl {1 -[(butylamino)carbonyl]-1 H-benzimidazol-2-yl}carbamate and carbendazim, methyl 1H-benzimidazol-2-ylcarbamate (MBC), in wettable powder (WP) formulations. In this method, benomyl is converted to 3-butyl-2,4-dioxo-s-triaz-ino[1,2-a]benzimidazole (STB) in 0.125M sodium hydroxide. After conversion (at room temperature in 20 min), STB is determined simultaneously with MBC (which remains intact with the sodium hydroxide treatment) at 286 nm after LC separation on a C18 column. The method was accurate and showed good reproducibility, with relative standard deviations of 0.7 and 2.2% for benomyl and MBC determinations, respectively.
Rapid Gas Chromatographic Method for the Multiresidue Screening of Fruits and Vegetables for Organochlorine and Organophosphate Pesticides
Authors: Pylypiw Harry M 
Published: February 2020

Abstract
A rapid and reliable method was developed for the determination of pesticides in fruits and vegetables. A100 g sample is extracted with a mixture of 200 mL petroleum ether and 100 mL 2-propanol. The extract is backwashed 4 times, twice with aqueous sodium sulfate and twice with 350 mL distilled water, and then dried over 15 g sodium sulfate. The dried extract is analyzed by capillary gas chromatography with selective organochlorine and organophosphorus detection. The method determines primarily nonpolar pesticides, with recoveries ranging from 81 to 114%, and has an average limit of detection of 10 ppb for both detectors.
Determination of 2-Methoxy-3-alkylpyrazines in Carrot Products by Gas Chromatography/Nitrogen–Phosphorus Detection
Authors: Lund Eric D 
Published: February 2020

Abstract
The 2-methoxy-3-alkylpyrazines in 6 types of carrot products were determined by a stripping–selective trapping procedure followed by purge-and-trap gas chromatographic analysis with an NP detector. The aroma threshold of one of the principal pyrazines, 2-methoxy-3-sec-butylpyrazine, in a carrot medium was 0.19 ng/g. The concentrations of this compound in whole-carrot products were 0.43 (fresh), 0.291 (canned, cooked), and 0.224 ng/g (frozen). A diced, cooked, and freeze-dried product contained 0.070 ng/g. All of these products contained only this pyrazine. In contrast, a shredded, bagged product contained 2-methoxy-3-isopropylpyrazine as the sole pyrazine (0.32 ng/g), and a sliced, dried product contained a mixture of 3 pyrazines: 2-methoxy-3-sec-butyl- (0.109 ng/g), 2-methoxy-3-iso-propyl- (0.176 ng/g), and 2-methoxy-3-isobutylpyra-zine (0.029 ng/g). The pyrazine concentrations in most of these products (except the freeze-dried product) exceeded the threshold value.
Detoxification of Citrinin and Ochratoxin A by Hydrogen Peroxide
Authors: Fouler Sophie G , Trivedi Alka B , Kitabatake Naofumi 
Published: February 2020

Abstract
The effects of hydrogen peroxide on citrinin and ochratoxin A toxicity were examined using HeLa cells. The citrinin was completely detoxified by prior incubation with 0.05% hydrogen peroxide for 30 min at room temperature, and the toxic compound(s) that resulted from heating citrinin at 100°C were also detoxified upon reheating it with hydrogen peroxide. On the other hand, ochratoxin A was not detoxified by hydrogen peroxide at room temperature, but its toxicity was reduced by heating ochratoxin A with hydrogen peroxide under alkaline conditions.
Determination of Polymerized Triglycerides in Frying Fats and Oils by Gel Permeation Chromatography: Interlaboratory Study
Authors: Beljaars Paul R , Van Dijk Remmelt , Houwen-Claassen Adrie A M 
Published: February 2020

Abstract
An interlaboratory study of the gel permeation chro-matographic (GPC) determination of polymerized triglycerides (PTG) in frying fats and oils was conducted by the Project Group on Collaborative Studies (PCS) of the Inspectorate for Health Protection, Food Inspection Service, The Netherlands. Thirteen laboratories participated in this study, which was focused on thermally abused oil and fat samples containing dimerized and polymerized triglycerides at levels just below and far above the Dutch regulatory limit of 16% (m/m). Samples were dissolved in tetrahydrofuran (THF) and analyzed on a GPC system, using THF as the mobile phase. Refractive index (Rl) detection was used to determine PTG. Six heat-processed fat samples containing from 14 to 28% (m/m) PTG at 3 different levels (3 pairs of split level samples) were single analyzed according to the proposed procedure. Data analysis was performed according to the International Union of Pure and Applied Chemistry/International Organization for Standardization/AOAC protocols for statistics. The results of 2 collaborators were identified as outliers at the 20% (m/m) PTG level by applying the paired Grubbs test at the 1% level of significance. The repeatability relative standard deviation (RSDr) values ranged from 0.48 to 2.25%, whereas the reproducibility relative standard deviation (RSDr) values ranged from 1.34 to 4.57%.
Liquid Chromatographic Determination of Sarafloxacin Residues in Channel Catfish Muscle Tissue
Authors: Meinertz Jeffery R , Dawson Verdel K , Gingerich William H , Cheng Bea , Tubergen Mark M 
Published: February 2020

Abstract
A liquid chromatographic method is described for the determination of sarafloxacin hydrochloride residues in channel catfish (Ictalurus punctatus) fillets. Sarafloxacin was extracted from fillet tissue with acetonitrile–water (1+1). The extract was centrifuged and the supernatant was partitioned with hexane. The aqueous fraction was filtered through a 0.45 μm filter and evaporated to dryness. The sample was redissolved with 20% acetonitrile–methanol (3 + 2) and 80% trifluoroacetic acid (0.1%), centrifuged, and filtered to remove proteins. Samples were analyzed by chromatography with gradient elution on a C18 column and with fluorescence detection (excitation at 280 nm and emission above 389 nm). Mean recoveries ranged from 85.4 to 104%, and relative standard deviations ranged from 1.06 to 5.58% in samples spiked at concentrations of 10.0–863.8 ng/g. The method detection limit for sarafloxacin was 1.4 ng/g.
Monitoring Pesticide Residues in Olive Products: Organophosphorus Insecticides in Olives and Oil
Authors: Lentza-Rizos Chaido 
Published: February 2020

Abstract
A simple and efficient gas-liquid chromatographic method was used to screen and quantitate residues of azinphos ethyl, chlorpyrifos, diazinon, di-methoate, fenthion, fenthion sulfoxide, methi-dathion, parathion ethyl, and parathion methyl in olive fruit and olive oil. Most olive fruit samples analyzed during 1991-1992 either contained no detectable residues of the insecticides or contained low concentrations of fenthion, dimethoate, and chlorpyrifos. One sample contained fenthion sulfoxide at a level exceeding FAO/WHO Codex Ali-mentarius maximum residue levels (MRL) for total fenthion. Commercially packed oil samples either contained no detectable residues of the insecticides or contained low concentrations of fenthion, fenthion sulfoxide, and chlorpyrifos. More than half of the virgin oil samples collected from individual growers contained no detectable residues. The others contained mostly fenthion and its sulfoxide metabolite. Of the samples analyzed, 13% exceeded Codex MRL for total fenthion residues. These samples were from a monitoring program targeted at produce most likely to contain residues. Refining procedures seem to act as a decontamination technique for oil containing fenthion residues.
Liquid Chromatographic Determination of Multiple Sulfonamide Residues in Bovine Milk: Collaborative Study
Authors: Smedley Michael D 
Published: February 2020

Abstract
A collaborative study involving 8 laboratories was conducted on the determination of 8 sulfonamide residues in raw bovine milk using a liquid chromatographic (LC) method. The sulfonamides are extracted with chloroform-acetone, the organic phase is evaporated, the residues are dissolved in an aqueous potassium phosphate solution, and the fatty residues are removed by washing with hex-ane. The aqueous layer is collected, filtered, and infected onto an LC system, and the analyte is detected by ultraviolet (UV) absorption at 265 nm. To quantitate all 8 sulfonamides isocratically, 2 chromatographic conditions are required: 12% methanol in the mobile phase for 5 sulfonamides, and 30% methanol in the mobile phase for 4 sulfonamides. Sulfamethazine (SMZ), the most widely used sulfonamide, is detected by both systems. Collaborators were instructed to analyze 3 replicates each of control milk and control milk fortified at 3 levels. They were also provided with 20 blind incurred samples (10 samples in duplicate) to analyze. For 10 ppb fortified milk, the average interlabo-ratory recovery for the 8 sulfonamides ranged from 56.2% for sulfaquinoxaline (SQX) to 82.7% for SMZ in the 12% methanol mobile phase (SMZ12). Also at this level, Sr, ranged from 3.2 for SQX to 8.9 for SMZ12, and SR ranged from 6.9 for sulfadimethox-ine to 17.2 for SMZ in the 30% methanol system (SMZ30). At 10 ppb, RSDr and RSDR ranged from 5.7% for SQX to 10.8% for SMZ12, and 10.1% for sul-famerazine to 20.9% for SMZ30, respectively. These results demonstrate that the method is suitable for the determination of the 8 sulfonamide residues in mHk at 10 ppb. However, the identification of positives by this procedure needs additional confirmation by procedures comparable to the specificity achievable by liquid or gas chromatography combined with mass spectrometry.
Evaluation of a Gas Chromatographic Method to Identify Irradiated Chicken, Pork, and Beef by Detection of Volatile Hydrocarbons
Authors: Schreiber Georg A , Schulzki Grit , Spiegelberg Almuth , Helle Norbert , Bögl Klaus W 
Published: February 2020

Abstract
A method suitable for routine application was used in an interlaboratory study to detect irradiation treatment of chicken carcass, pork, and beef. By using gas chromatographic analysis, 17 participating laboratories determined the quantity of 4 different radiation-induced volatile hydrocarbons (tetradecene, pentadecane, hexadecadiene, and neptadecene) in the fat fraction of coded specimens approximately 3 and 6 months after irradiation. The specimens of each type of meat were supplied by 2 different producers. The dose range tested (0.6-7.5 kGy) included levels commercially used to reduce the number of contaminating microorganisms (1-5 kGy). The method employed permitted a correct identification of irradiated or nonirradiated in 98.3% of the 864 specimens.
Integration of Liquid Chromatography with Immunoassay: An Approach Combining the Strengths of Both Methods
Authors: Krämer Petra M , Li Qing X , Hammock Bruce D 
Published: February 2020

Abstract
The integration of liquid chromatography (LC) with immunochemical detection combines the superior separation power of LC and the sensitivity and specificity of immunoassays. This approach is shown with 3 LC systems (Perkin-Elmer, C18 RP, 4.6 mm; Varian, C18 RP, 1 mm microbore; Michrom, C18 RP, 1 mm microbore) Integrated with an enzyme-linked immunosorbent assay (ELISA) selective for five 4-nitrophenols. The nitrophenols were separated with the 3 LC systems with isocratic runs of 15 to 20 min. Microbore LC separation showed a 10-20 times reduction in solvent amount compared to conventional separation. LC–immunoassay was about 8- to 10-fold more sensitive compared with LC with UV detection. Integrated LC–immunoassay proved to be a very selective method when 2-methylphenol was injected with an equimolar mixture of 2-amino-4-nitrophenol and 3-methyl-4-nrtrophenol; 2-methy I phenol does not crossreact with the serum used. Only 2 peaks could be seen in the detection, even when 2-methylphenol was present in very high amounts (3000 pmol). Further, the EUSA-LC detection proved to be selective and sensitive for complex matrixes. 2-Amlno-4-nitrophenol was clearly identified in spiked extracts of soil and plant, even when a very small amount (2.4 ng) was injected. Although LC–immunoassay is more labor intensive than LC with UV detection, it offers great advantages in multiresidue analysis and is generally applicable for peak confirmation.