bluuebunny/crossref_metadata_2025_split huggingface dataset:
Staphylococcus aureus
Authors: Bergdoll Merlin S 
Published: February 2020

Abstract
The analytical methods for the detection of the staphylococcal enterotoxins can be divided into 2 categories: (1) methods for detection of enterotoxin-producing staphylococcal strains; (2) methods for detection of enterotoxin in foods. Gel diffusion methods (Ouchterlony, microslide), in which the enterotoxin produced by any given strain is compared to one of the identified enterotoxins, are used most frequently for strain testing. The sensitivity of these methods is from 0.1 to 0.5 μg enterotoxin/mL, which is normally adequate to determine the enterotoxigenicity of strains. The methods for the detection of enterotoxin in foods need to be much more sensitive to detect less than 1 ng of enterotoxin/g of food that may be present. The radioimmunoassay (RIA), the enzymelinked immunosorbent assay (ELISA), and the reversed passive latex agglutination (RPLA) method have the necessary sensitivity to detect 1 ng/g of enterotoxin in foods without the use of complicated extraction-concentration procedures. Kits based on the ELISA and RPLA methods are now available commercially for the detection of enterotoxins in foods. Tests have shown that the ELISA methods are somewhat more sensitive than the RPLA method.
Liquid Chromatographic Determination of Chlortetracycline Hydrochloride in Ruminant and Poultry/Swine Feeds
Authors: Holland David C , Faul Kent C , Roybal Jose E , Munns Robert K , Shimoda Wilbert 
Published: February 2020

Abstract
A liquid chromatographic (LC) method is described for the determination of chlortetracycline hydrochloride (CTC) in poultry/swine and ruminant feeds in the 10-100 ppm range and in premix. CTC is extracted from ground feed/premix with acidified acetone, and the extract is filtered through a Millex-HV filter or disposable C 18 column. The filtrate Is partitioned with methylene chloride when additional cleanup is necessary. A Nova-Pak C 18 column Is used for LC separation with determination at 370 nm. The average recovery of CTC from premix was 95% with a standard deviation (SD) of 1.70 and a coefficient of variation (CV) of 1.79%. The overall average recovery from feeds was 77% with an SO of 3.18 and a CV of 4.10%.
Competitive Direct Enzyme-Linked Immunosorbent Screening Assay for the Detection of Sulfamethazine Contamination of Animal Feeds
Authors: Holland Deborah Dixon E , Katz Stanley E 
Published: February 2020

Abstract
A sensitive screening method has been developed for detecting sulfamethazine (SMZ) contamination of feeds by using either polyclonal or monoclonal antibodies and a direct competitive enzyme-linked immunosorbent screening assay (ELISA). Feed samples of 25.0 g are extracted with 0.5N HCI and centrifuged. The extract is adjusted to pH 7.0 with 3.0N NaOH and recentrifuged. This pH-adjusted extract is used in the EUSA. Levels as low as 0.004 μg SMZ/g feed were detected In supplemented extracts by polyclonal antibodies; levels of 0.4 μg SMZ/g feed were detected by a monoclonal antibody.
Reducing Solvent Consumption in Automated Gel Permeation Chromatographic Cleanup for Pesticide Residue Analysis: A Modified GPC AutoPrep 1002
Authors: Patterson John R 
Published: February 2020

Abstract
Modifications to the gel permeation chromatographic apparatus recommended in AOAC method 984.21 for multiresidue analysis of organochlorine pesticides in animal fat are described. By using 1.0 mL sample loops and a 1.0 cm id column, organic solvent usage was reduced by 85%. Organochlorine pesticides were collected in a 14 mL fraction. Mean recoveries using the modified apparatus for aldrin, α-BHC, lindane, dieldrin, p,p′-DDD, p,p′-DDE, p,p′-DDT, heptachlor, heptachlor epoxide, methoxychlor, and mirex from beef fat fortified at 0.10-2.75 μg/g were in the 91.4-108% range, with CV of 3.3-10.0%.
Liquid Chromatographic Determination of Paraquat and Diquat in Crops Using a Silica Column with Aqueous Ionic Mobile Phase
Authors: Chichila Tina M , Walters Stephen M 
Published: February 2020

Abstract
A method was developed for the determination of paraquat (PQ) and diquat (DQ) in high moisture food crops. Samples were digested with 6M HCI, and the herbicides were isolated from the digest using pH-controlled silica solid phase extraction. The analyte8 were then determined by ion-pairing liquid chromatography with a silica analytical column, sodium chloride as the ion-pairing reagent, and acetonitrile as the organic modifier. A diode array UV absorbance detector was used to simultaneously quantify PQ and DQ at their respective maximum absorbance wavelengths, 257 and 310 nm. Average recoveries of PQ and DQ standards from 4 different crops fortified at 0.01-0.50 ppm levels ranged from 79.3 to 104.8%.
Quantitative Analysis of Agricultural and Food Products: A New Instrumental and Computerized Approach
Authors: Lanher Bertrand S 
Published: February 2020

Abstract
A new software package, ANAQUANT, was specifically designed for a long-term approach to the quantitation of compounds In biological products. Its functionality and validity were tested by measuring fat and protein contents In liquid cow's milk using Fourier transform Infrared spectrometry and a handcrafted transmission flow cell. Calibration and validation standard deviations were 0.2484 and 0.3987 g/kg, respectively, for the prediction of proteins, and 0.3163 and 0.4222 g/L, respectively, for the prediction of butterfat. One month elapsed between calibration of the Instrument and the validation study. Results are consistent with those proposed in the literature.
Determination of Dicloxacillin Preparations by Liquid Chromatography
Authors: Hsu Mei-Chich , Fann Yann-Jen 
Published: February 2020

Abstract
A reversed-phase liquid chromatographic method was developed for the assay of dicloxacillin In bulk drugs and pharmaceutical preparations. The samples were analyzed on a μBondapak (C18) column with a mobile phase of methanol-4% acetic acid (60 + 40) at a flow rate of 1.5 mL/mln, with UV absorbance detection at 254 nm. An equation was derived showing a linear relationship between peak area ratios of dicloxacillin to dimethylphthalate (internal standard) and the dicloxacillin concentration over a range of 2-30 μg (r = 0.9999). Standard addition recoveries ranged from 98.65 to 100.74% (mean 99.70%, n = 6). The coefficient of variation was less than 0.24%. The assay results were compared with those obtained by the official microbiological method, which indicated that the proposed method Is a suitable substitute for the microbiological method for potency assays and stability studies of dicloxacillin preparations.
Column Extraction of Residues of Several Pesticides from Fruits and Vegetables: A Simple Multiresidue Analysis Method
Authors: Kadenczki Lajos , Arpad Zoltan , Gardi Ivan , Ambrus Arpad , Gyorfi Laszlo , Reese Gabriela , Ebing Winfried 
Published: February 2020

Abstract
Homogeneous sample pulp, prepared from fruits and vegetables of different water content with or without additional water, Is adsorbed on the surface of activated Florisll to obtain a free-flowing powder, which is extracted In a glass column with ethyl acetate or methylene chloride-acetone (9 + 1, v/v). In most cases, no further cleanup Is necessary for subsequent gas chromatographic measurement. The recovery of pesticide residues, Including carbamate, organochlorlne, organophosphate, synthetic pyrethrold, triazlne, urea, and miscellaneous pesticides, Is generally ≥80%, and Is Independent of the sample material. The column extraction Is faster, less laborious, and less expensive than extractions based on traditional techniques, liquid partition, or other conventional chromatographic procedures.
Composition of Pineapple Juice
Authors: Krueger Dana A , Krueger Rae-Gabrielle , Maciel Jeanne 
Published: February 2020

Abstract
Major and some minor constituents were determined for a series of fresh pineapple juices. Results Include: soluble solids 11.2-16.2 g/100 g, acidity (reported as citric acid) 0.46-1.21 g citric acid/100 mL, fructose 1.72-4.75 g/100 mL, glucose 1.21-4.52 g/100 mL, sucrose 2.47-9.73 g/100 mL, citric acid 0.439-1.151 g/100 mL, malic acid 0.073- 0.391, Isocltrlc acid 80-265 mg/L, potassium 830- 1410 mg/L, formol value 0.74-1.69 meq/100 mL, proline 11-44 mg/L, and carbon isotope ratio 13.5- 11.2%o PDB. Use of these compositional values In the detection of adulterated pineapple juice is discussed.
Determination of Insoluble and Soluble Dietary Fiber in Foods and Food Products: Collaborative Study
Authors: Prosky Leon , Asp Nils-Georg , Schweizer Thomas F , Devries Jonathan W , Furda Ivan 
Published: February 2020

Abstract
A collaborative study was conducted to validate a method to determine the Insoluble dietary fiber (IDF) and soluble dietary fiber (SDF) contents of foods and food products by using a combination of enzymatic and gravimetric procedures. The method was basically the same as that for determining total dietary fiber, which was adopted as final action by AOAC and further modified to Include changes in the concentration of buffer and base and substitution of hydrochloric acid for phosphoric acid. Thirty-nine collaborators were each sent 7 test samples In a staggered design for duplicate blind analysis. They were also sent a standard containing 4.3-5.4% IDF and 1.5-2.7% SDF. The 22 foods that were analyzed for IDF and SDF were cabbage, carrots, French beans, kidney beans, butter beans, okra, onions, parsley, chick peas, brussels sprouts, barley, rye flour, turnips, soy bran, wheat germ, raisins, Callmyrna figs, prune powder, Black Mission figs, apple powder, peach powder, and apricot powder. Both IDF and SDF values were calculated as the weight of residue minus the weight of protein and ash reported on a dry weight basis. The reproducibility relative standard deviation (RSDR) of the IDF results ranged from 3.68 to 19.44% for the foods analyzed; almost half the test samples had an RSDR &lt;10%. The RSDR values for the SDF results were somewhat higher. Approximately 50% of the foods analyzed had an RSDR &gt;20%, and 45% had an RSDR between 10 and 20%. An RSDR approaching 45% was calculated for the 2 test samples with the lowest SDF content, 1.35 and 1.90%. Raisins and prune powder had high RSDR values for both SDF and IDF. A major reason for high RSDR values seems to be filtration problems, which are avoidable by analyzing 0.5-0.25 g test samples. The method for the determination of SDF requires further study, but the method for the determination of IDF was adopted first action by AOAC International.
History of the IUPAC/ISO/AOAC Harmonization Program
Authors: Horwitz William 
Published: February 2020

Abstract
As a result of the preference of the Joint Food and Agriculture Organization/World Health Organization Codex Alimentarius Program to endorse methods of analysis for which interlaboratory performance parameters are available, many international organizations now conduct method-performance (collaborative) studies. International meetings sponsored by the International Union of Pure and Applied Chemistry, the International Organization for Standardization, and AOAC International have produced a harmonized protocol for the design, conduct, and interpretation of method-performance studies, and this protocol Is being Implemented by many method standardization organizations. The same group of organizations hopes to provide a harmonized protocol for the quality control and quality assurance of laboratory (analyst) performance.
Liquid Chromatographic Determination of Gentian Violet in Poultry Feed
Authors: Roybal José E , Munns Robert K , Holland David C , Burkepile Roger G , Hurlbut Jeffrey A 
Published: February 2020

Abstract
A liquid chromatographic (LC) method Is presented for the determination of gentian violet (GV) In poultry feed (turkey/chicken) at the therapeutic feeding level of 4-8 ppm. GV Is extracted from feed with acidified methanol, an aliquot of the supernatant is diluted with mobile phase, and the solution is filtered. LC analysis Is performed by Isocratlc elutlon with a buffered mobile phase on an Adtech CN (cyano) column with amperometrlc electrochemical detection (ED) at +1.000 V or detection in the visible absorbance mode at 588 nm. The overall average recovery of GV from chicken feed spiked at 2.5,5, and 10 ppm was 103% (standard deviation = 6.6; coefficient of variation = 6.4%) by LC/ED analysis. Data for recovery of GV from chicken and turkey feeds, fortified with 1% GV premlx at feeding levels of 4 and 8 ppm, are presented and discussed. Data for the 2 detection techniques are compared.
Bioassay, Extraction, and Purification Procedures for Wortmannin, the Hemorrhagic Factor Produced by Fusarium oxysporum N17B Grown on Rice
Authors: Abbas Hamed K , Mirocha Chester J , Shier W Thomas , Gunther Roland 
Published: February 2020

Abstract
Rats and cultured cells were treated with purified wortmannin toxin, crude fungal extracts, and partially purified preparations for periods of 5-96 h. A single dose of the toxic fractions containing the equivalent of 2.5 g fungus-infested rice resulted in death, hematuria, and hemorrhage in the urinary bladder, Intestine, stomach, heart, and thymus of rats. Purified wortmannin produced the same effects at 4 mg/kg. Fractions that were toxic in vivo also had cytotoxic properties with various cultured cell lines at concentrations ranging from 1.2 to &gt;50 mg equivalents of fungus-infested rice extracted/mL Purified wortmannin was cytotoxic at 50 μg/mL.
Multiresidue Method for Quantitation of Organophosphorus Pesticides in Vegetable and Animal Foods
Authors: Leoni Valerio , Caricchia Anna M , Chiavarini Salvatore 
Published: February 2020

Abstract
A critical review of multiresidue analytical methods was performed to develop an easy procedure that can be applied with slight modifications to vegetable and animal food samples. The multiresidue method described Is applicable to the quantitative determination of 28 organophosphorus pesticides In fatty as well as nonfatty foods. The foods are divided Into 4 groups according to extraction process (acetone and acetone-water for samples with moisture content &lt;45%) and cleanup (on active carbon- Cellte, on disposable mlnicolumns of Kieselguhr- type material, and on disposable mlnicolumns of bonded-phase silica, according to fat and pigment content). A further fractionation on silica-gel microcolumns can be Included In the procedure. A wide-bore column (SPB-5) with flame photometric detection operated in phosphorus mode (FPD-P) was chosen for gas chromatographic determination. Recoveries from apples, olive oil, whole milk, pasta, and eggs are reported. Two packed columns (4% OV-101 and SP2250- SP2401) with FPD-P were tested as confirmation columns. The method is suitable for a total diet study.
Detection of Beef, Sheep, Deer, and Horse Meat in Cooked Meat Products by Enzyme-Linked Immunosorbent Assay
Authors: Andrews Connie D , Berger Ronald G , Mageau Richard P , Schwab Bernard , Johnston Ralph W 
Published: February 2020

Abstract
Enzyme-linked Immunosorbent assays (ELISAs) are described for the detection of mutton, beef, horse meat, and venison In cooked meat products. They represent an expansion of the species detection capabilities of previously described ELISAs for the detection of pork and poultry In cooked foods. These double antibody sandwich ELISAs recognize heat-resistant antigens in simple aqueous extracts of cooked meat products. Tests on laboratory-prepared and commercially cooked meat products accurately differentiated all tested meat components. However, some canned baby food meats and one canned meat product did not react in any of these ELISAs. Sensitivity of the assays was 0.13% or greater in tests of diluted cooked extract mixtures. No product Ingredients were found that interfered with test performance.
Direct Determination of Individual Organic Fluorine Compounds by Aluminum Monofluoride Molecular Absorption Spectrometry
Authors: Venkateswarlu Pothapragada , Blackwell John A , Jewell Kelly , Kirsch Gary W 
Published: February 2020

Abstract
Recovery of organic fluorine by direct aluminum monofluoride molecular absorption spectrophotometry, following injection of samples into the graphite furnace and use of sodium fluoride standards, varies from 0 to 100% from compound to compound depending on the compound's volatility and the mechanism of thermal decomposition. This problem has now been overcome by employing standards made from the very same fluorochemical that is present in the sample. This approach is applicable to samples containing only 1 known fluorochemical. Some industrial applications of this technique that meet the needs of quality control, industrial hygiene policies, and certain U.S. Food and Drug Administration regulations are described.
Analysis of Fatty and Nonfat Foods for Chlorophenoxy Alkyl Acids and Pentachlorophenol
Authors: Hopper, Marvin L , Mcmahon Bernadette , Griffitt Kenneth R , Cline Kevin , Mary Ellen Fleming-Jones , Kendall Donald C 
Published: February 2020

Abstract
A multiresidue method has been developed to analyze low-level residues of chlorophenoxy alkyl acids and pentachlorophenol (PCP) in fatty and nonfat foods. The acidified sample is extracted, cleaned up using gel permeation chromatography, methylated by ion-pair alkylation with tetrabutylammonium hydroxide and methyl iodide, cleaned up using Florisil, and determined by gas chromatography using electron capture and/or electrolytic conductivity detectors. Recoveries ranged from 53 to 75% for 2,4-D at 200 ppb, 61 to 93% for 2,4,5-T at 80 ppb, and 76 to 84% for PCP at 20 ppb fortified in a variety of food items. Also, 31 other herbicides were evaluated through this procedure.
Liquid Chromatographic Screening Method for Fluorescent Derivatives of Chlorophenoxy Acid Herbicides in Water
Authors: Suzuki Toshinari , Watanabe Satoru 
Published: February 2020

Abstract
A liquid chromatographic method for screening 9 chlorophenoxy acids (2,4-D; 2,4-DP; 2,4-DB; MCPA; MCPP; MCPB; 2,4,5-T; 2,4,5-TP; and 2,4,5-TB) and their ethyl esters in ground- and tap water is presented. The water samples are acidified and subjected to either liquid-liquid or solid-phase extraction. The extracts obtained are saponified in 0.03N NaOH-50% methanol (1+1) and the acidic compounds are re-extracted with ethyl acetate-n-hexane (8 + 2) after acidification and derivatized with 9- anthryldiazomethane. Derivatized compounds are analyzed using reversed-phase column chromatography with fluorescence detection (excitation, 365 nm; emission, 412 nm). Recoveries of analytes from 20 mL water samples were greater than 90%, and the average coefficient of variation was within 5.0% at 0.5 ppb for both extraction methods. These methods are simple and useful for the determination of small amounts of chlorophenoxy herbicides. Solid-phase extraction is suitable for screening a large number of samples simultaneously, and liquid extraction for separate determination of the acids and ethyl esters of the herbicides was improved by introducing a saponification step.
Determination Of Tryptophan Content In Infant Formulas And
Medical Nutritionals
Authors: Garcia Saul E , Baxter Jeffrey H 
Published: February 2020

Abstract
A method was developed for determination of total tryptophan content in soy- and milk-based nutritional products. The method uses enzymatic (pronase) digestion of the protein to release tryptophan, which is separated and quantitated by isocratic reversed-phase liquid chromatography with fluorescence detection. Enzymatic digestion is completed for products containing these types of proteins in less than 6 h and is accomplished under chemically mild conditions (pH 8.5,50°C), which do not significantly degrade tryptophan. Chromatographic separation is complete in about 8 min, including an internal standard. The precision of the method is 1-2% relative standard deviation. Accuracy is demonstrated by agreement with theoretical values for standard proteins (amino acid sequence known) and by quantitative recoveries of overspikes, which use either free tryptophan or a standard protein as the spiking material. The method allows determinations on samples containing a wide range of tryptophan values. Appropriate sample size selection and verification of digestion time requirements should allow the method to be applied to different protein types as well. The method allows 24 h turnaround of tryptophan analyses, and quantitative recoveries represent a significant improvement on existing techniques applied to infant formulas and other nutritional products.
Survey of Bottled Drinking Water Sold in Canada. Part 1.
Lead, Cadmium, Arsenic, Aluminum, and Fluoride
Authors: Dabeka Robert W , Conacher Henry B S , Salminen John , Nixon Gerald R , Riedel Gunther , Crocker Ron , DubÉ Gilles 
Published: February 2020

Abstract
Samples of bottled water (n = 172) offered for sale in Canada were analyzed for lead, cadmium, arsenic, aluminum, and fluoride: means and ranges (μg/g) found were, respectively, 0.0026 (&lt;0.0010- 0.074), 0.00018 (&lt;0.0001-0.0004), 0.0030 (&lt;0.001- 0.048), 0.027 (&lt;0.010-0.568), and 0.543 (&lt;0.050- 5.85). Comparison of levels among mineral waters (n = 64), spring waters (n = 77), and miscellaneous waters (n = 31) indicated appreciable differences only in the case of fluoride. For fluoride, the means and medians (μg/g) for mineral, spring, and miscellaneous waters were 1.179 and 0.455, 0.152 and 0.090, and 0.201 and &lt;0.050, respectively. No samples were found in violation of the tolerances in the Canadian Food and Drug Regulations; however, 1 sample (in a lead-soldered can) contained lead and 15 samples contained fluoride at levels above the limits recommended by the Guidelines for Canadian Drinking Water (tap-water) Quality.
Spectrophotometric Method for Determination of Cephalexin
in Its Dosage Forms
Authors: Patel Ila T , Devani Muljibhai B , Patel Tushar M 
Published: February 2020

Abstract
A simple, rapid, and specific method was developed for determination of cephalexin and its dosage forms. The method is based on the reaction of cephalexin with acetylacetone-formaldehyde reagent to give a yellow chromophore measurable at 400 nm. The color is stable for 3 h. Beer's law is valid within a concentration range of 10-100 μg/mL for cephalexin. All variables were studied to optimize the reaction conditions. The method is specific for amino β-lactam antibiotics. Non-amino β-lactam antibiotics do not interfere. No interference was observed in the presence of common pharmaceutical adjuvants. The validity of the method was tested by analyzing cephalexin tablets, capsules, and oral suspension. Good recoveries were obtained for these preparations. The results were comparable with those obtained by the official procedure
Survey of Arsenic in Total Diet Food Composites and Estimation of the Dietary Intake of Arsenic by Canadian Adults and Children
Authors: Dabeka Robert W , McKenzie Arthur D , Lacroix Gladys M A , Bowe Chantal Cleroux Susan , Graham Russell A , Conacher Henry B S , Verdeer Pam 
Published: February 2020

Abstract
During a comprehensive total diet study extending from 1985 to 1988, foods were collected in 6 Canadian cities (in one of them, a pilot study was conducted twice). For each of the 7 collections, foods were processed into 112 composites (105 in the initial pilot trial). Total arsenic was determined in all samples. The mean, median, and range of arsenic concentrations in all samples were 73.2,5.1, and &lt;0.1-4830 ng/g, respectively. Food groups containing the highest mean arsenic levels were fish (1662 ng/g), meat and poultry (24.3 ng/g), bakery goods and cereals (24.5 ng/g), and fats and oils (19.0 ng/g). The estimated daily dietary ingestion of total arsenic by the average Canadian was 38.1 μg and varied from 14.9 μg for the 1- to 4-year-old group to 59.2 μg for 20- to 39-year-old males.