bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative Evaluation of Bacteria Washed from Stainless Steel Penicylinders During AOAC Use-Dilution Method
Authors: Alfano Edith M , Cole Eugene C , Rut Ala William A 
Published: February 2020

Abstract
Stainless steel penicylinders inoculated separately with test bacteria {Salmonella choleraesuis, Pseudomonas aeruginosa, or Staphylococcus aureus) are used in the AOAC use-dilution method (UDM) for disinfectant efficacy testing. Numbers of bacteria remaining on penicylinders were quantitatively assessed to determine if cells are washed from the penicylinders after a 10 min exposure to phosphate buffer dilution water (PBDW). Inoculated penicylinders were also examined by scanning electron microscopy (SEM) to determine the presence of cells remaining attached to the penicylinders after a 10 min exposure to a quaternary ammonium disinfectant and separately to PBDW. The percentage of cells washed from inoculated penicylinders exposed to PBDW was 89.9 for Salmonella choleraesuis, 48.8 for Pseudomonas aeruginosa, and 38.8 for Staphylococcus aureus. Qualitative examination of penicylinders by scanning electron microscopy confirmed the attachment of S. aureus and P. aeruginosa cells to penicylinders exposed separately to PBDW and a quaternary ammonium disinfectant. Few S. choleraesuis cells were observed on penicylinders exposed to PBDW and no cells were observed after disinfectant exposure. The variability of the numbers of viable cells entering the recovery media among the 3 UDM test bacteria due to cell detachment could be a significant factor in the recognized variability of the use-dilution method.
Comparison of Babcock and Ether Extraction Methods for Determination of Fat Content of Milk: Collaborative Study
Authors: Barbano David M , Clark Jenny L , Dunham Chapman E 
Published: February 2020

Abstract
Eleven collaborating laboratories analyzed 18 blind duplicate pairs of raw milk samples for fat by the Babcock method and by a modified Mojonnier ether extraction method in 7 round robins conducted over a 14 month period. Ten laboratories used the Babcock method and 10 used the modified Mojonnier method. Fat content of samples ranged from approximately 2.7 to 5.6%. Mean test value of samples analyzed was approximately 3.9% fat. Average standard deviations of within-laboratory repeatability (Sr) of the Babcock and ether extraction methods were 0.029 and 0.015% fat, respectively. Average standard deviations of between-laboratory reproducibility (SR) of the Babcock and ether extraction methods were 0.039 and 0.020% fat, respectively. Average repeatability relative standard deviations (RSDr) for the Babcock and ether extraction methods were 0.742 and 0.396%; average reproducibility relative standard deviations (RSDR) were 1.014 and 0.512%, respectively. Mean repeatability values (r) and reproducibility values (R) were 0.081 and 0.111% for Babcock and 0.044 and 0.056% for ether extraction, respectively. The ether extraction method demonstrated consistently better within- and between-laboratory agreement. The overall mean test value for the Babcock method was significantly higher (0.021% fat) than that for ether extraction. The difference between Babcock and ether extraction fat test results was different for different farms. In addition, the mean difference between percent fat determined by the Babcock and ether extraction methods was different in different months. There was no correlation in the difference between Babcock and ether extraction methods with the absolute level of fat in the samples in the range of 2.7 to 5.6% fat. The modifications of the AOAC Babcock method and the modified Mojonnier ether extraction method have been approved interim official first action.
Liquid Chromatographic Determination of the Estrogens Daidzein, Formononetin, Coumestrol, and Equol in Bovine Blood Plasma and Urine
Authors: Lundh Torbjorn J O , Pettersson Hans , Kiessling Karl-Heinz 
Published: February 2020

Abstract
A liquid chromatographic (LC) method is described for the determination of the plant estrogens daidzein, formononetin, and coumestrol and the estrogenically active metabolite equol in bovine blood plasma and urine. The blood and urine samples are incubated overnight with and without β3-glucuronidase/sulfatase for analysis of both free and conjugated forms of estrogens. Samples are applied to Extrelut ® columns, extracted with ethyl acetate, and evaporated to dryness. Residues from urine samples are dissolved in methanol, diluted with water, acidified with HCl, and purified by injection through a Sep-Pak® C,8 cartridge. This eluate is used for LC analysis. Residues from blood samples are dissolved in benzene-petroleum ether (1 + 1), extracted with ammonium hydroxide, acidified with glacial acetic acid, and extracted with ethyl acetate. The ethyl acetate extract is evaporated, dissolved in 80% methanol, injected onto a LC reversephase column, and separated in a linear gradient system between 40 and 80% methanol in phosphate buffer. Quantitation is performed by means of UV and fluorescence responses. The method was sensitive enough to determine 0.4 μg/mL of daidzein and formononetin and 0.1 and 13 ng/mL of coumestrol and equol, respectively, in blood, and 130,80, and 7 ®g/mL of daidzein, formononetin, and coumestrol, respectively, and 4 Mg/mL of equol in urine. The applicability of the method was checked by the determination of total and free plant estrogens in blood samples from a dairy cow fed a normal diet.
Liquid Chromatographic Method for Determination of Azinphos-Methyl in Formulated Products: Collaborative Study
Authors: Slahck Stephen C 
Published: February 2020

Abstract
A liquid chromatographic method for determination of azinphosmethyl (Guthion®) in formulated products has been developed. Samples are dissolved in acetonitrile and analyzed by reverse-phase chromatography using n-butyrophenone as an internal standard. The method was subjected to a collaborative study involving 15 participating laboratories. Each collaborator was furnished with reference standard, internal standard, and blind duplicate samples of Guthion 50% wettable powder (50WP), 3 flowable (3F), and emulsifiable concentrate (2L and 2S) formulations. Collaborators were instructed to evaluate the method by peak height measurements only. Relative standard deviations for reproducibility (RSDR) were 1.11, 6.28, 2.47, and 1.17% for the 50WP, 3F, 2L, and 2S formulations, respectively. The method has been approved interim official first action for determination of azinphos-methyl in the 50WP, 2L, and 2S formulations.
Liquid Chromatographic Determination of Rotenone in Fish, Crayfish, Mussels, and
Sediments
Authors: Dawson Verdel K , Allen John L 
Published: February 2020

Abstract
An analytical procedure is described for determining residues of rotenone in fish muscle, fish offal, crayfish, freshwater mussels, and bottom sediments. Tissue samples were extracted with ethyl ether and extracts were cleaned up by gel permeation chromatography and silica gel chromatography. Sediment samples were extracted with methanol, acidified, partitioned into hexane, and cleaned up on a silica gel column. Rotenone residues were quantitated by liquid chromatography, using ultraviolet (295 nm) detection. Recoveries from sediment samples fortified with rotenone at 0.3 μg/g were 80.8%, whereas recoveries from tissue samples fortified with 0.1 μg/g ranged from 87.7 to 96.8%. Samples fortified with 0.3 μg/g and stored at - 10°C for 6 months before analysis had recoveries ranging from 83.2 to 90.5%. Limits of detection were 0.025 μg/g for sediments and 0.005 μg/g for tissue samples
Liquid Chromatographic Determination of Olaquindox in Medicated Feeds and in Contents of
Porcine Gastrointestinal Tract
Authors: Spierenburg Theo J , Van Lenthe Henk , De Graaf Gertjan , Jager Lowie P 
Published: February 2020

Abstract
A liquid chromatographic method for the determination of olaquindox in both medicated feeds and porcine gastrointestinal tract is described. Samples are extracted with water and cleaned on a disposable reverse-phase column. The eluate is chromatographed on a reverse-phase column under isocratic conditions. Olaquindox is detected by UV absorption at 260 nm. The minimum amount detected by this method was 0.075 ng. The corresponding minimum detectable concentration in a 1 g sample was 0.3 mg/kg. The detector response was linear within the interval of 0-500 ng. Mean recovery of olaquindox in spiked gastrointestinal samples was 89 ± 5% (mean ± standard deviation, n = 43). Concentration profiles of olaquindox in the gastrointestinal tract of pigs fed medicated feed were used to evaluate the preventive potency against Treponema hyodysenteriae. The presence of some N-O reduced metabolites of olaquindox in the gastrointestinal tract was assessed
Liquid Chromatographic Determination of Propyl Paraben in Cigarette Filler
Authors: CastaÑo Jorge I , Palacio Francisco J , Vargas Luis R 
Published: February 2020

Abstract
A liquid chromatographic method for the quantitative determination of propyl paraben in cigarette tobacco filler has been developed. Propyl paraben is extracted from cigarette tobacco filler with acetonitrile and further purified using a silica Sep-Pak® cartridge and ethyl acetate-petroleum ether (1 + 4) as eluting solvent. The purified extracts are analyzed by reverse-phase liquid chromatography using buffered water (pH 4)-acetonitrile (65 + 35) as mobile phase, with UV detection at 254 nm. Cut tobacco samples were fortified with 100 and 200 ppm propyl paraben. Average recoveries (N = 5) of propyl paraben were 98 and 94%, respectively, with coefficients of variation less than 4%.
Competitive Direct Enzyme-Linked Immunosorbent Assay for Detection of
Sulfamethazine Residues in Swine Urine and Muscle Tissue
Authors: Dixon-Holland Deborah E , Katz Stanley E 
Published: February 2020

Abstract
A sensitive assay for the detection of sulfamethazine in swine urine and muscle tissue using a direct competitive enzyme-linked immunosorbent assay (ELISA) has been developed. Undiluted urine or a phosphate-buffered saline extract of pork muscle tissue is mixed with an enzyme-labeled conjugate of sulfamethazine and horseradish peroxidase. The mixture is added to wells of a microtiter plate coated with antibody to sulfamethazine. After the test system is incubated, washed, and re-incubated with substrate and the reaction is stopped, the absorbance is measured at 405 nm. Levels of sulfamethazine as low as 20 ng sulfamethazine/g muscle tissue and 10 ng sulfamethazine/ mL swine urine were detected and estimated
Liquid Chromatographic Determination of L-Ascorbate 2-Polyphosphate in Fish Feeds by
Enzymatic Release of L-Ascorbate
Authors: Wang Xiao-Ying , Liao Ming-Long , Hung Tsui-Hwa , Seib Paul A 
Published: February 2020

Abstract
An accurate method was devised to assay L-ascorbic 2-polyphosphate esters (AsPP) in fish feed by phosphatase digestion followed by determination of the released L-ascorbic acid (AsA). Compressed yeast and dithiothreitol are added to the phosphatase reaction mixture to give 95-100% recovery of AsA, which is quantitated by reverse-phase liquid chromatography (LC) with electrochemical detection. Chromatograms of all feed digests showed baseline resolution of AsA. In 3 feeds, to which 75-125 ppm AsA equivalents in the form of AsPP were added, the assay procedure gave 98-100% recovery of AsA
Liquid Chromatographic Determination of Zearalenone and a- and 0-Zearalenols in Milk
Authors: Scott Peter M , Lawrence Guillaume A 
Published: February 2020

Abstract
Previous research has demonstrated transmission of zearalenone and α- and β-zearalenols into the milk of cows and other animals. Since human intake of zearalenone and its metabolites via milk is an unknown factor in risk assessment of zearalenone and because appropriate methodology for their determination in milk is not available, a rapid and sensitive analytical method has been developed. Essentially, the method includes extraction with basic acetonitrile, acidification, partition into methylene chloride on a hydrophilic matrix, cleanup on an aminopropyl solid phase extraction column, and reverse- phase liquid chromatography with fluorescence detection. Recoveries from milk averaged 84% for zearalenone, 93% for α-zearalenol, and 90% for β-zearalenol at spiking levels of 0.5 to 20 ng/ mL. As little as 0.2 ng/mL of zearalenone and a-zearalenol and 2 ng/mL of 0-zearalenol can be detected in milk. These 3 compounds are stable in refrigerated milk for at least 2 weeks and in milk brought to boiling. Enzymes (β-glucuronidase and aryl sulfatase) may be added to milk prior to extraction to hydrolyze any conjugates
Evaluation of APHA and AOAC Methods for Phosphatase in Cheese
Authors: Murthy Gopala K , Cox Samuel 
Published: February 2020

Abstract
Varieties of market cheese were analyzed for alkaline phosphatase by the modified rapid colorimetric method of the American Public Health Association (APHA) and the official AOAC method, 16.304- 16.306. In the APHA method, 5 g cheese (pH &lt;7.0) is macerated with 2 mL 1:1 carbonate buffer, or 2 mL water (for cheese with pH &gt;7.0). Addition of 0.1 mL magnesium acetate (1 mg magnesium) to test portions of cheese extracts yielded reproducible and quantitative recovery of added phosphatase. In the AOAC method, macerating 0.5 g cheese with 1 mL borate buffer before adding milk phosphatase improved recovery among cheeses. Addition of magnesium ion increased phosphatase activity in some cheeses. Phosphatases in blue mold-ripened and Swiss cheeses were inactivated by heat faster than was milk phosphatase, yet milk phosphatase added to various soft cheeses was completely inactivated at 60°C for 10 min. The lability of phosphatase was due to the heat-denaturing effect of NaCl present in finished cheeses. Some Mexican style soft cheeses contained both heat-labile and heat-stable phosphatases. These data suggest that the phosphatase test to differentiate milk and microbial phosphatases on the basis of repasteurization and analysis of cheese is no longer valid
Liquid Chromatographic Determination of Saccharin in Beverages and Desserts:
Complementary Collaborative Study
Authors: SjÖberg Anna-Maija K 
Published: February 2020

Abstract
A complementary collaborative study was conducted on a liquid chromatographic method for determination of saccharin in accordance with the latest international recommendations. One industrial and 6 official food control laboratories analyzed 3 samples of a juice, a soft drink, and a dessert at concentration levels of 26-90 mg/L, 33-73 mg/L, and 56-147 mg/kg, respectively. Blind duplicates and a blank were supplied for each type of material at each concentration level. The beverage was chromatographed directly and the dessert was extracted with ethanol before chromatography. Average recoveries were 95-107%. The reproducibility relative standard deviations were 6.4-7.3% for the juice, 9.2-20.6% for the soft drink, and 13.4-16.2% for the dessert. The outlier percentage was 14.3%. The results were compared with those of an earlier collaborative study by Nordic laboratories and with general collaborative results obtained by AOAC
Radionuclides in Domestic and Imported Foods in the United States, 1983—1986
Authors: Cunningham William C , Stroube William B , Baratta Edmond J 
Published: February 2020

Abstract
Findings in the Food and Drug Administration's Radionuclides in Foods program are summarized for samples collected between October 1,1982, and September 30,1986. All radionuclide findings for Total Diet and reactor samples were either in Action Range I or low in Range II of the surveillance and control recommendations given by the Federal Radiation Council. The only long-range trend noted was a continuation of the general decline in dietary intake of "Sr since 1961. Imported food samples were analyzed for contamination after the Chernobyl nuclear accident. The findings for imported foods indicate that the surveillance efforts successfully targeted contaminated foods, and that contamination levels were below levels of concern for all but one oregano and 3 cheese samples.
Experimental Designs for Interlaboratory Precision Experiments: Comparison of ISO 5725 with Draft NEN 6303
Authors: Zaalberg J 
Published: February 2020

Abstract
To determine the precision of standardized analytical methods, interlaboratory experiments are carried out in which several laboratories analyze identical samples from well homogenized batches of material. From the test results, estimates of the standard deviations under repeatability as well as under reproducibility conditions are calculated. In the present work, the experimental designs recommended in the International Standard ISO 5725 have been compared with a design proposed in the draft Netherlands Standard NEN 6303. This has been done by comparing their mathematical models as well as by applying them to the results of a recent collaborative study on the determination of heavy metals in edible oils and fats. The reproducibility standard deviation is estimated equally well with both Standards, but it appeared that the designs given in ISO 5725 can lead to serious underestimation (uniform-level design) or overestimation (split-level design) of the repeatability standard deviation. By using the design proposed in NEN 6303, these biases can be avoided. Hence, it is recommended that interlaboratory studies be organized according to the design of NEN 6303.
Limited Survey of Deoxynivalenol in Wheat and Corn in the United States
Authors: Wood Garnett E , Carter Lawrence 
Published: February 2020

Abstract
A limited survey was conducted over a 2-year period to determine the incidence and levels of deoxynivalenol (DON) in corn and wheat grown in selected areas of the United States. Samples of corn (198) and wheat (247) were collected and analyzed by a gas chromatographic method. Sixty-six percent of the corn samples collected in 1984 and 30% of the corn samples collected in 1985 contained DON. The average concentration of DON in corn, by state, ranged from 0.11 to 1.20 μg/g; the maximum concentration was 2.47 μg/g. Only 2 of the 247 samples of wheat contained DON at a concentration &gt;2 μg/g, which is the level of concern suggested by the Food and Drug Administration for wheat entering the milling process for human consumption.
Liquid Chromatographic Determination of Acids and Sugars in Homolactic Cucumber Fermentations
Authors: Lázaro Maria Jesus , Carbonell Elvira , Aristoy Maria Concepcion , SafÓn Jose , Rodrigo Miguel 
Published: February 2020

Abstract
A rapid, high yield, and quantitative method for determination of sugars (glucose and fructose) and acids (malic, lactic, acetic, and citric) in fresh and fermented cucumber juices is described; the procedure solves the fructose and malic acid coelution problem. Samples are prepared by passing the juice directly through a disposable C18 cartridge. Compounds are separated by liquid chromatography on an Aminex HPX-87H chromatographic column, with 0.013N H2S04 as mobile phase in the isocratic mode at 0.6 mL/min flow rate and 60°C column temperature. Compounds are then detected and quantitated by using ultraviolet and refractive index detectors connected in series, and comparing with succinic acid as internal standard. Values for both fresh and fermented cucumber juices were in good agreement with literature data.
Food Directorate of Canada Contributions to the Association of Official Analytical Chemists
Authors: Coffin D Earle 
Published: February 2020

Abstract
The Food Directorate of the Health Protection Branch, Department of National Health and Welfare, Canada, is a committed supporter of the aims and operation of AOAC. The Directorate and its staff members have made significant contributions to AOAC over the past 40 years, presently contribute to many aspects of the operation of AOAC, and will continue their support for the betterment of both organizations. This support relies on an organizational policy of cooperation with AOAC in method development, on the coordination of individual work programs with AOAC activities, and on the voluntary commitment of time and effort by a group of individuals. The present paper is a record of the contributions of the Food Directorate and its predecessors to AOAC and its purpose of providing validated analytical methods for regulatory use.
Microbiological Determination of Neomycin in Feeds: Collaborative Study
Authors: Stahl Gerald L , Kratzer D Dal , Kasson Charles W 
Published: February 2020

Abstract
A modification of the AOAC microbiological determination of neomycin in feeds was collaboratively studied by 12 laboratories. The official method was modified by substituting a constant salt concentration diluent for the feed extract diluent, preparing the agar medium in tris buffer, and performing the test with a monolayer plating system. Each laboratory performed single assays on 8 samples in a randomized sequence. The samples included duplicates of a cattle and swine feed at 2 different marketed concentrations. The mean recovery across all laboratories was 110.7% of theory with a range of means of 69.4-128.6 across the 12 laboratories. The results of one laboratory and 2 additional values from different laboratories were deemed outliers and excluded from statistical analysis. The statistical analysis gave a confidence interval of ± 26% for individual assays.
Simultaneous Liquid Chromatographic Determination of Water-Soluble Vitamins, Caffeine, and Preservative in Oral Liquid Tonics
Authors: Maeda Yumie , Yamamoto Masatoshi , Owada Kazuhiro , Sato Shiro , Nakazawa Hiroyuki 
Published: February 2020

Abstract
A rapid, simple, and reliable liquid chromatographic method has been developed for the simultaneous determination of nicotinamide (niacinamide), thiamine, riboflavin, riboflavin sodium phosphate, pyridoxine, caffeine, and sodium benzoate in commercial oral liquid tonics. The 7 components are separated on a reverse phase C18 column using a mobile phase of acetonitrile-O.OlM potassium dihydrogen phosphate-triethylamine (8 + 91.5 + 0.5 v/v/v) containing 5mM sodium octanesulfonate and adjusted to pH 2.8 with phosphoric acid. Components are detected at 254 nm with attenuation 0.02 AUFS. Acetanilide is used as an internal standard. In addition to the 7 components mentioned, nicotinic acid (niacin), cyanocobalamin, and folic acid are also separated under the same conditions. Sample preparation involves only addition to internal standard solution and dilution with mobile phase and then filtration. Recoveries of the 7 components and cyanocobalamin from spiked preparations ranged from 97 to 104% with coefficients of variation of 0.9-4.2%.