bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Qualitative Colorimetric Test for Brominated Vegetable Oil in Soft Drinks
Authors: Murthy M N Krishna , Rajalakshmi S , Satyabodha J A , Nagaraja K V 
Published: February 2020

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

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

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

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

Abstract
Seventeen laboratories participated in a collaborative study to validate an automated conductance method for the rapid detection of Salmonella in food. The conductance method was compared with the standard BAM/AOAC method for the Isolation of Salmonella. Media for the conductance method were supplied In ready-to-use, disposable, singleuse cells of a novel, unique design. Samples of coconut, fish meal, prawns, nonfat dried milk, liquid egg, and minced beef were artificially contaminated with different Salmonella serotypes to 2 target levels of 1-5 cells/25 g and 10-50 cells/25 g. Each participating laboratory tested 10 contaminated and 5 noncontaminated samples per product. Results showed no significant difference between BAM/AOAC and conductance methods. The conductance method was adopted by AOAC International as a first action method.
A Survey of Benzene in Fruits and Retail Fruit Juices,Fruit Drinks, and Soft Drinks
Authors: Page, Denis B , Conacher, Henry B.S , Weber, Dorcas , Lacroix, Gladys 
Published: February 2020

Abstract
Recent findings of benzene In several fruit-flavored mineral waters at low μg/kg levels, reportedly arising from added benzoate, have prompted a survey of various fruits, juices, and drinks for traces of benzene. Headspace sampling, capillary gas chromatography, and mass spectrometrlc detection enabled detection with confirmation (full-scan spectrum) of benzene as low as 0.03 μg/kg. With selected Ion monitoring, the method detection limit was 0.02 μg/kg, I.e., 3 times the analytical blank, in total, 97 samples were analyzed. Benzene was found at levels ranging from 0.018 to 3.83 μg/kg. Samples labeled to contain added benzoate or believed to contain natural benzoate, such as cranberries, were found to contain benzene at higher levels (n = 41, av. 0.66 μg/kg) than other samples (n = 32, av. 0.082 μg/kg). Average levels of benzene In fruits (as expressed juice), In juices with and without benzoate, In noncarbonated drinks with and without benzoate, and in soft drinks with and without benzoate were 0.042,0.672,0.056,0.395, 0.116,0.793, and 0.062 μg/kg, respectively
Internal Standard Stable Carbon Isotope Ratio Method for Determination of C-4 Plant Sugars in Honey: Collaborative Study, and Evaluation of Improved Protein Preparation Procedure
Authors: White Jonathan W 
Published: February 2020

Abstract
A collaborative study of the internal standard isotope ratio method for measuring C-4 plant sugars in honey Is reported. For 5 Youden pairs of samples containing 2-14% C-4 sugars, analyzed by 9 laboratories, mean sr was 1.92% and SR was 2.19%. Improved performance parameters for determination of δ13C in honey are also presented. The method was adopted first action by AOAC International. Also presented Is an improved purification procedure for the honey protein required for the Internal standard method. The dialysis-precipitation procedure described is considerably less demanding of analyst's time and eliminates possible contamination of the preparation by Indigenous yeasts and molds. No difference In δ13C values was found between the collaboratively studied method and the method when used with the improved procedure to analyze 10 known pure honeys. The dialysis- precipitation procedure is recommended as a substitute for the repeated washing procedure described In the collaboratively studied method.
Determination of Malachite Green and Its Leuco Form in Water
Authors: Allen John L , Meinertz Jeffery R , Gofus Jane E 
Published: February 2020

Abstract
Liquid chromatographic (LC) analysis can detect malachite green residues in water at less than 10µg/L. Water samples were concentrated on disposable diol columns, eluted with 0.05M p-toluenesulfonic acid in methanol, and determined by reversed- phase LC. When combined with a lead oxide postcolumn reactor, the LC method can simultaneously determine both leuco and chromatic forms of malachite green. Recoveries averaged 95.4% for the chromatic form and 57.3% for the leuco form of malachite green oxalate and leuco malachite green in spiked pond water samples. Recoveries of the carbinol form of malachite green (an equilibrium product of the dye in water) from spiked tap water samples averaged 98.6%. Recoveries of leuco malachite green were low and pH-dependent.
Analysis of Polychlorinated Biphenyls in Aqueous Samples Using C18 Glass Column Extraction
Authors: Moltó, Juan C , Picó, Yolanda , Mañes Jorge , Font Guillermina 
Published: February 2020

Abstract
A method for polychlorinated biphenyl (PCB) trace extraction from contaminated water at the part-pertrillion levels is described. This procedure involves quantitative adsorption of PCBs on Cis glass microcolumns. PCBs are retained on the surface and subsequently eluted with n-hexane (5 mL) before gas chromatography. Recovery of water fortified with PCBs was 83.6-108.5%. Compared to liquid-liquid extraction methods, the Cis glass microcolumns give comparable results, lessen solvent costs, and are less time-consuming.
In Vitro Effect of Multiple Antibiotic/Antimicrobial Residues
on the Selection for Resistance in Bacteria
Authors: Sue Brady Marietta , Katz Stanley E 
Published: February 2020

Abstract
A method using a gram-positive and a gram-negative organism was used to investigate the selection for resistant populations after exposure to residue levels of 7 antibiotics and 1 antimicrobial. The organisms were exposed to individual compounds and combinations of 3 compounds for 14 days. The changes in minimum inhibitory concentration (MIC) of a panel of 8 antibiotics and 1 antimicrobial were used as the measure of resistance development/selection. For Staphylococcus aureus ATCC 9144, exposure to residue levels of oxytetracycline, tylosin, penicillin, and virginiamycin resulted in an increased MIC of the compound itself; most individual residues did not result in increased cross-resistance. With combinations of residues, 13 of 45 determinations resulted in significant increases in MIC. Enterobacter cloacae B520, which was much less sensitive to 4 of 9 markers, showed MIC increases only for tylosin and the combination of neomycin-sulfamethazine-oxytetracycline. The results indicate an interaction among residue levels of antibiotics in selection for resistance.
Liquid Chromatographic Determination of Unbound and Acetone-Soluble Bound Gossypol in Cottonseed Meals and Mixed Feeds
Authors: Botsoglou Nickos A 
Published: February 2020

Abstract
A liquid chromatographic method has been developed for the determination of unbound and acetone- soluble bound gossypol in cottonseed meals and mixed feeds at levels of 0.5 ppm. The method involves extraction with aqueous acetone in the presence of ascorbic acid, hydrolysis of the "soluble bound" forms with hydrochloric acid, partitioning into chloroform, and chromatographic separation on a 10 µm C18 column by step gradient elution using a methanol-water mobile phase acidified with phosphoric acid. With minor modifications, the method permitted discriminate determination of unbound gossypol and acetone-soluble hydrophilic and lipophilic forms of bound gossypol. The gossypol peak was characterized by on-line spectral scanning and absorbance rationing. Overall relative standard deviation was 6.7% and overall recovery was 98.1 ± 3.3%. When the method was applied to several cottonseed meal samples, results were inconsistent with those obtained by the official American Oil Chemists' Society method for "free" gossypol determination.
Characterization of the 0-(2,3,4,5,6-Pentafluorobenzyl)- hydroxylamine Hydrochloride (PFBOA) Derivatives of Some Aliphatic Mono- and Dialdehydes and Quantitative Water Analysis of These Aldehydes
Authors: Cancilla Devon A , Chou Chin-Cheng , Barthel Richard , Que Hee Shane S 
Published: February 2020

Abstract
A study was conducted to validate the use of O- (2,3,4,5,6-pentafluorobenzyl) hydroxylamine hydrochloride (PFBOA) as an agent for the determination of formaldehyde, acetaldehyde, n-heptanal, n-decanal, and glyoxal, aldehydes commonly found as byproducts in drinking and other water after a prior ozonation step. The study involved synthesis and characterization of the pure PFBOA-oxime derivatives and their subsequent use in validation studies in various types of chemically defined waters. The yields of the synthesized PFBOA-oximes exceeded 80%. They were characterized by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, ultraviolet (UV) and infrared (IR) spectrophotometry, and gas chromatography/electron impact positive ion mass spectrometry (GC/MS) to assess their purity and define the suitability of these techniques in aldehyde quantitation. The syn/anti isomers of the oximes were detected by GC/MS and both NMR techniques, but not by IR or UV. The most sensitive technique was selected ion monitoring GC/MS, which allowed picogram quantitation over a wide linear range. A high PFBOA concentration (10 mg/mL) with 3 hexane extractions, initial pH adjustment, and microwave heating proved superior (&lt;80% recoveries) to a published method involving room temperature, low PFBOA concentration (1 mg/mL), and a single hexane extraction for many defined waters. The use of standard reference materials as defined matrixes for aldehyde spiking recovery experiments to account for matrix effects is novel, and demonstrates that the method is quantitative (&lt;80% recoveries) in a wide variety of matrixes.
Gravimetric Determination of Moisture and Ash in Meat and Meat Products: NMKL Interlaboratory Study
Authors: Kolar Kurt 
Published: February 2020

Abstract
Fourteen laboratories participated in a collaborative study of gravimetric methods for determination of moisture and ash in meat and meat products. The determination of moisture by drying without sand at 102-105C for 16-18 h and to constant weight was compared with the official NMKL method using drying with sand to constant weight. The incineration was performed at 550°C. The method was tested on 16 blind duplicate samples of fresh meat and meat products ranging in moisture content from 44.1 to 74.8 g/100 g, and in ash content from 1.0 to 5.4 g/100 g. Drying without sand for 16-18 h and to constant weight gave no significant difference. Therefore, the labor-intensive drying to constant weight is not necessary to obtain reliable results. In comparison with the official NMKL method based on drying with sand, the mean values, repeatability, and reproducibility of the drying method without sand for 16-18 h agree very well. Therefore, there is no reason to retain the more complicated and labor-intensive sand drying method. The conditions of the proposed method differ only slightly from the conditions used in the official AOAC method, 950.46 B(a). The collaborative results for the determination of both moisture and ash gave estimates for precision according to the HORRAT values
Determination of Arsenic in Vegetable Samples by Hydride
Generation Atomic Absorption Spectrometry
Authors: Navarro Miguel , Lopez Maria C , Lopez Hermbmia , Sanchez Mercedes 
Published: February 2020

Abstract
A procedure is described for the determination of arsenic in vegetable samples by hydride generation atomic absorption spectrometry. The samples are mineralized in a microwave acid digestion bomb with nitric acid in the presence of small amounts of vanadium pentoxide. The determination of arsenic is made by the standard addition method. A certified reference sample is analyzed, and the result obtained agreed well with the certified value. The detection limit (dry weight) was about 0.020 μg/g. Reproducibility relative standard deviations ranged from 6.45% at 0.152 μg A μ/g to 8.31 % at 0.059 μg A μ/g. The concentrations of arsenic in vegetable samples ranged from 0.029 to 0.444 μg/g (fresh weight)
Graphite-Furnace Atomic Absorption Spectrometric Determination And Survey Of Total Aluminum, Copper, Manganese, Molybdenum, And Tin In Infant Formulas And Evaporated Milks
Authors: Dabeka Robert W , Mckenzie Arthur D 
Published: February 2020

Abstract
A graphite-furnace atomic absorption spectrometric (GFAAS) method using a single simple digestion was developed to determine aluminum, copper, manganese, molybdenum, and tin in infant formulas and evaporated (evap.) milks. Citric acid (0.5 mL 20%) and 3 mL HNO3 were added to 2 g formula (ready-to-use basis) in unwashed polystyrene test tubes. Tubes were capped, and solutions were digested 6-18 h at 55C. Digests were diluted to 10 mL with water and analyzed. Standards were prepared in a matrix of 30% HNO3 and 1% citric acid without digestion. Palladium (1 μg) was used as matrix modifier for aluminum and tin determinations. The mean detection limits of the method were 0.021,0.043, 0.006, 0.063, and 0.073 μg/g for aluminum, copper, manganese, molybdenum, and tin, respectively. The elements were determined in 191 Canadian infant formulas and evap. milk samples. Means, medians, and ranges (μ/g) of metals in soy-based ready-to-use formulas were as follows: 1.62, 0.54, and 0.23-5.2 for aluminum; 0.87,0.88, and 0.71-1.14 for copper; 0.63,0.22, and 0.042-2.4 for manganese; 0.068, &lt;0.049, and &lt;0.048-0.14 for molybdenum; and 0.20, 0.15, and &lt;0.074-0.54 for tin. Means, medians, and ranges (μg/g) of metals in milk-based ready-to-use formulas were as follows: 0.18,0.13, and &lt;0.011-0.66 for aluminum; 0.61, 0.58, and 0.44-0.93 for copper; 0.097,0.094, and 0.053- 0.16 for manganese; 0.033, &lt;0.042, and &lt;0.012- 0.067 for molybdenum; and 0.23,0.18, and 0.067-0.91 for tin. Respective levels in evap. milks (as sold) were as follows: 0.08, 0.051, and &lt;0.017- 0.27 for aluminum; 0.103, 0.087, and 0.045-0.31 for copper; 0.071, 0.062, and 0.048-0.16 for manganese; 0.14, &lt;0.17, and &lt;0.07-&lt;0.19 for molybdenum; and 2.84,0.46, and 0.032-48 for tin.
HPLC Receptorgram: A Method for Confirmation and Identification of Antimicrobial Drugs by Using Liquid Chromatography with Microbial Receptor Assay. I. Sulfonamides in Milk
Authors: Zomer Eliezer , Saul Steven , Charm Stanley E 
Published: February 2020

Abstract
A determinative method was developed for confirmation, identification, and quantitation of 12 sulfonamide residues and p-aminobenzoic acid (PABA) in milk. This method, termed "HPLC receptorgram," uses liquid chromatography in conjunction with the microbial receptor assay (MRA) to monitor sulfonamides. The MRA for sulfonamides (commercialized as the Charm II test) uses a microcrobial receptor and [3H]sulfamethazine tracer. Sulfonamides in milk bind to the receptor and inhibit the binding of the tracer to the receptor. Milk samples spiked at 10 ppb for each sulfonamide result in at least a 50% decrease in binding on the HPLC receptorgram, with the exception of sulfanilamide and sulfacetamide, which give approximately a 25% decrease. Additionally, milk samples spiked at the minimum detection level of the MRA assay can be confirmed, identified, and quantitated with coefficients of variation (%) of 7.6-24. Analysis of market milk samples found positive by the MRA showed 9 samples containing sulfamethazine, 4 samples containing sulfadimethoxine, 2 samples containing sulfadoxine, 2 samples containing sulfadiazine or sulfathiazole, and 1 sample each containing sulfisoxazole or sulfapyridine. Three samples contained multiple sulfonamide residues. Ten sulfonamides are determined with an isocratic buffer elution system containing 22% acetonitrile mobile phase. p-Aminobenzoic acid (PABA), an interfering sulfonamide analog, sulfanilamide, and sulfacetamide are eluted by using a 10% acetonitrile mobile phase
Methods of Analysis for Toxic Elements in Foods. Part IV. General Method of Ashing for the Determination of Toxic Elements
Authors: Skurikhin Igor M 
Published: February 2020

Abstract
As a result of the request of the Codex Alimentarius Committee on Methods of Analysis and Sampling, a general method for ashing of foods for the determination of toxic elements was assembled. This method consolidates the results of more than a decade of interlaboratory work of numerous USSR food laboratories and specifies the details of wet and dry ashing procedures.
Simultaneous Determination of Multiple Tetracycline Residues in Milk Using Metal Chelate Affinity Chromatography
Authors: Carson Mary C 
Published: February 2020

Abstract
A method was developed for the determination of 7 tetracyclines in milk. Raw milk samples are defatted, acidified, and centrifuged to remove proteins, and the tetracyclines are specifically absorbed from the milk by chelation with metal ions bound to small Chelating Sepharose Fast Flow columns. The tetracyclines are removed from these columns with EDTA-containing buffer, and the extracts are further cleaned up by centrifugal ultrafiltration. Finally, the extracts are concentrated and analyzed simultaneously by on-line concentration. This method has limits of detection for individual tetracyclines of &lt;5 ng/mL and was validated with fortified milk samples at 15,30, and 60 ng/mL. Recoveries exceeded 60% for all tetracyclines at all levels, with good precision. The method was also tested on milk from cows dosed with each of the tetracyclines. Advantages of this method over existing methods include its sensitivity, minimal use of organic solvents, and speed; with an autosampler, at least 14 samples can be processed and analyzed in 1 day.
Development of Enzyme Immunoassay for Captan and Its Degradation Product Tetrahydrophthalimide in Foods
Authors: Newsome W Harvey , Yeung Jupiter M , Collins Peter G 
Published: February 2020

Abstract
A simple, sensitive, and precise enzyme-linked immunosorbent assay (ELISA) is described for the quantitation of captan as its degradation product tetrahydrophthalimide (THPI) in foods using polyclonal antibodies. Three hapten analogues of THPI with different alky I spacer arm lengths were synthesized. Immunogens and coating proteins were prepared by coupling these haptens to human serum albumin and ovalbumin, respectively. A 5-carbon spacer arm appeared to be optimum for the production of antibodies. Heterologous coating proteins did not improve the sensitivity, but reduction of homologous coating protein concentration did improve the sensitivity, resulting in a concentration of test compound required to inhibit binding by 50% of 15.5 ng/mL The antiserum is specific for captan, captafol, and THPI, but not other structurally related compounds. The minimum detection limit was 1 ng/mL; the linearity was 1-200 ng/mL. The overall recoveries of captan and THPI from 11 commodities spiked at 4 levels were 92 and 100%, respectively. The intra-assay and interassay coefficients of variation were 9.1 and 16.8% for apple blanks and 5.9 and 4.2% for apple spiked with 3 ppm THPI, respectively. The ELISA described is suitable for measuring captan and THPI at levels comparable to those typically found in fruit.