bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atomic Absorption Spectrophotometric Method for Determination of Polydimethylsiloxane Residues in Pineapple Juice: Collaborative Study
Authors: Parker Robert D 
Published: February 2020

Abstract
An atomic absorption spectrophotometric method for determination of polydimethylsiloxane (PDMS) residues In pineapple juice was collaboratively studied by 9 laboratories. PDMS residues are extracted from pineapple Juice with 4- methyl-2-pentanone and the extracted silicone Is measured by atomic absorption spectrophotometry using a nitrous oxide/ acetylene flame. Collaborators analyzed 5 samples Including 1 blind duplicate. Reproducibility relative standard deviations (RSDR) were 13.1% at 31 ppm, 6.9% at 18 ppm, 14.8% at 7.9 ppm, and 16.1 % at 4.9 ppm PDMS. The method has been approved Interim official first action by AOAC.
Optimization of the Determination of Cholesterol in Various Food Matrixes
Authors: Oles Philip , Gates Gloria , Kensinger Seth , Patchell Jacqueline , Schumacher David , Showers Tammy , Silcox Arlene 
Published: February 2020

Abstract
A fractional factorial (Taguchi) experiment was designed to optimize recovery of cholesterol from a baked food matrix. A pretzel sample was chosen for the spiking design experiment. Factors studied Include the alcohol used for saponification, the extraction solvent, hydrolysis conditions, spiking level, use of an antioxidant, and use of hexadecane to prevent physical losses. Of these, hydrolysis conditions and extraction solvent were most Influential In affecting recovery of cholesterol. A method was subsequently validated for determination of cholesterol In cookie, egg, and meat matrixes. The average recovery of spiked cholesterol was 102 ± 5.5% from a total of 29 samples representing these matrixes. The precision (1 slgma) for repetitive analyses of eggs Is about 3%; for sausage, 2%; and for cookies, 3%. The procedure has also been used for determination of cholesterol In pasta, mayonnaise, chocolate, whey, meat, eggs, and potato chips. Spike recoveries for a variety of foods were 93 to 106% with an overall average of 99% and a relative standard deviation of ±4%.
Kjeldahl Method for Determination of Total Nitrogen Content of Milk: Collaborative Study
Authors: Barbano David M , Clark Jenny L , Dunham Chapman E , Flemin Richard J 
Published: February 2020

Abstract
A macro-KJeldahl procedure using a copper catalyst for determination of milk total nitrogen was developed for both traditional and block dlgestor/steam distiller equipment, and the performance was evaluated by collaborative study. In the first trial of the collaborative study, 9 pairs of blind duplicate milk samples were analyzed for total nitrogen and total nitrogen was converted to "protein" by using a factor of 6.38. Protein content of milk samples ranged from 3.086 to 3.610%. In the first trial, sR and R values for the block dlgestors were influenced significantly by protein concentration; 8R and R values were not Influenced by protein concentration for traditional equipment. It was hypothesized that total digestion time for some block dlgestors In the first trial was not sufficient for high protein milk samples. Thus, a second trial was undertaken with boiling time after clearing Increased by 0.5 h. In the second trial, none of the parameters for reproducibility with either type of equipment were Influenced by protein concentration. It was concluded that laboratory-to-laboratory differences In line voltage may require different total digestion times in different laboratories, particularly those using block dlgestors. The Kjeldahl method using a copper catalyst and either traditional or block digestor equipment for determination of milk total nitrogen has been adopted official first action by AOAC to replace method 920.105.
Matrix Solid Phase Dispersion Isolation and Liquid Chromatographic Determination of Sulfadimethoxine in Catfish (Ictalurus punctatus) Muscle Tissue
Authors: Long Austin R , Hsieh Lily C , Malbrou Marsha S , Short Charles R , Barker Steven A 
Published: February 2020

Abstract
A method for the isolation and liquid chromatographic determination of sulfadimethoxine In catfish (Ictalurus punctatus) muscle tissue Is presented. Blank control and sulf adlmethox- Ine-fortlfled fish muscle tissue samples (0.5 g) were blended with octadecylsllyl (C18,40 /μm, 18% load, endcapped) derivatlzed silica packing material. A column made from the C18/ fish tissue blend was first washed with hexane (8 mL), following which the sulfadimethoxine was eluted with dlchloromethane (8 mL). The eluant contained sulfadimethoxine analyte that was free from Interfering compounds when analyzed by liquid chromatography with UV detection (photodlode array, 270 nm). Standard curves for sulfadimethoxine Isolated from fortified samples were linear (0.999 ± 0.001) with an average relative percentage recovery of 101.1 ± 4.2% for the concentration range (50, 100, 200,400, 800, and 1600 ng/g) examined using sulfamethoxazole as the Internal standard. The interassay variability was 10.7 ± 8.2% with an Intra-assay variability of 2.2%.
Automated Liquid Chromatographic Determination Of Aflatoxin Mi In Milk Using On-Line Dialysis For Sample Preparation
Authors: Th.Tuinstra Louis G.M , Kienhuis Paul G.M , Dols Peter 
Published: February 2020

Abstract
A procedure has been developed for the automated Isolation of aflatoxin M1 from decreamed milk. The method uses online stopped flow dialysis and subsequent trace enrichment on a reverse-phase column. After a back-flush to the analytical liquid chromatography column, aflatoxin M1 is determined with fluorescence detection. Fully automated analysis Is possible with reproducible dialysis recoveries above 50% (CV = 7.5%, n = 25 at the 50 ng/kg level) and determination levels of 20 ng/kg within 20 mln.
Sample Collection and Sample Preparation Techniques for Aflatoxin Determination in Whole Cottonseed
Authors: Park Douglas L , Rua Sam M , Paulson J H , Harder Dwight , Young Allan K 
Published: February 2020

Abstract
The present paper describes a comparative study between sampling devices used In the official sampling plan for Arizona cottonseed and a device that provides a smaller sampling size. The official sample must be greater than 30 lbs from at least ten 3 lb probes/cottonseed lot, not exceeding 100 tons. This Is accomplished using a Probe-A-Vac pneumatic or corkscrew sampler with a 3 in. diameter X 50 In. probe. The alternative sampling device evaluated In this study uses a modified shop-vac wet-dry vacuum with a 0.75 in. diameter X 100 in. probe. Ten 1 lb probes were taken for a total sample size of 10 lbs. Aflatoxin concentrations in cottonseed samples taken using both sampling probes at adjacent points throughout the lot were determined with an AOAC thin-layer chromatographic method (26.052-26.059, 14th Ed., 980.20AH, 15th Ed.). Mean total aflatoxin concentrations for Probe-AVac vs shop-vac samples from 39 lots (1987-1988 crop year) and 21 lots (1988-1989 crop year) were 76.6 vs 68.5 and 39.5 vs 30.7 µg/kg, respectively. Long staple cottonseed was sampled using a long staple trier (LS Trier), an alternative for which may be the shop-vac system. Mean total aflatoxin concentrations for LS Trier vs shop-vac for 7 lots (1988-1989 crop year) were 9.4 vs 5.1, µg/kg respectively. Also, an ultracentrlfugal mill has proven to be highly versatile for both denuding and grinding cottonseed to be tested under both laboratory and nonlaboratory situations.
Food and Drug Administration Pesticide Residue Monitoring of Foods: 1983-1986
Authors: Yess Norma J , Houston Marcia G , Gunderson Ellis L 
Published: February 2020

Abstract
Pesticide residues In foods are reported for the 4-year period 1982-1986 [fiscal years (FY) 83-86]. Results were summarized from the 2 complementary approaches that make up the Food and Drug Administration's (FDA) pesticide residue monitoring program. Under regulatory monitoring, which focuses on residues in raw agricultural commodities, a total of 49 055 samples (27 700 domestic and 21 355 import) that Included fresh fruits and vegetables, grains and grain products, milk and dairy products, seafoods, and a variety of processed foods were analyzed. No residues were found In 60 and 48% of the domestic and Import samples, respectively, compared with 55 and 44% in FY78-82. About 3% of the domestic and 5% of the import samples were violative. In FY78-82, about 3 and 7% were violative, respectively. The other FDA monitoring approach, the Total Diet Study, was revised in April 1982 to expand coverage of age/sex groups, use updated diets, and provide for analysis of individual foods. Results from monitoring under this modified approach and from regulatory monitoring continued to demonstrate that pesticide residues In the U.S. food supply were well below regulatory limits, and dietary Intakes were many times lower than the Acceptable Daily Intakes established by international agencies
A Study of Ten Toxins Associated with Paralytic Shellfish Poison Using Prechromatographic Oxidation and Liquid Chromatography with Fluorescence Detection
Authors: Lawrence James F , Ménard Cathie , Charbonneau Claudette F , Hall Sherwood 
Published: February 2020

Abstract
Ten paralytic shellfish toxins [saxltoxln, neosaxltoxin, B-1, B- 2, gonyautoxin 1, 2, and 3 (i.e., GTX-1, GTX-2, and GTX-3), C-1, C-2, and C-3] were oxidized at room temperature under mildly basic conditions with hydrogen peroxide or periodic acid. The products were then analyzed by liquid chromatography (LC). The N-1-hydroxylated toxins (neosaxltoxin, B-2, GTX-1, and C-3) formed fluorescent products after periodate oxidation at ca pH 8.7, but did not form fluorescent derivatives with peroxide oxidation. The non-N-1-hydroxylated toxins (saxltoxln, B-1, GTX-2, GTX-3, C-1, and C-2) formed highly fluorescent derivatives with both peroxide and periodate oxidations. Individual toxins produced mainly single fluorescent peaks by reverse-phase LC. However, all GTX toxins eluted with the same retention time. Also, C-1 and C-2 eluted together, as did neosaxltoxin and B-2. The non--N-1- hydroxylated toxins could be detected In quantities as low as 20-50 pg/lnjectlon, while the N-1-hydroxy analogues could be detected at levels as low as 100-500 pg/lnjectlon. UV absorption and fluorescence emission spectra were similar for the oxidation products of all toxins examined (max. 333 ± 2 nm absorption, 389 ± 4 nm fluorescence emission).
Capillary Gas Chromatographic Determination of Cyclohexanone and 2-Ethyl-l-Hexanol Leached from Solution Administration Set
Authors: Danielson James W 
Published: February 2020

Abstract
A capillary gas chromatographic method is described for the determination of cyclohexanone and 2-ethyl-1-hexanol leached from solution administration sets. A preliminary study was made of compounds leached from solution administration sets by 5% sodium bicarbonate solution (pH 8.1), 0.9% sodium chloride solution (pH 6.8), and water. Water was selected as the leaching solvent because similar quantities of the compounds were leached into water and into both types of parenteral solutions. The correlation coefficients were 0.99977 for cyclohexanone and 0.99974 for 2-ethyl-1- hexanol, and recoveries were good (93-94%). Five administration sets from each of 2 manufacturers were analyzed by this method. The amounts of cyclohexanone that were leached from the individual sets varied considerably; however, similar quantities were leached from sets of both manufacturers. 2-Ethyl-1-hexanol was also found in extracts from each of the sets analyzed.
Quantitation and Confirmation of Sulfamethazine Residues in Swine Muscle and Liver by LC and GC/MS
Authors: Carignan Germain , Carrier Karen 
Published: February 2020

Abstract
The present paper describes a liquid chromatographic (LC) method for purification of crude swine tissue extracts before gas chromatographic/mass spectrometric (GC/MS) quantitation and confirmation of sulfamethazine at low ppb levels. Fractions corresponding to sulfamethazine were collected, evaporated to dryness, ^methylated with diazomethane, concentrated, and analyzed by GC/MS. A mass spectrometer was set to selected ion monitoring (SIM) mode. Ions 233, 227, 228, and 92 m/z were detected. Ratio 227/233 m/z (sulfamethazine/internal standard, [pheny| 13C6] sulfamethazine) was used for quantitation, while ratios 228/227 and 92/ 227 m/z, respectively, were used for confirmation. Quantitation in spiked blank muscle tissue was tested from 100 to 1 ppb and found acceptable at all concentrations studied; coefficients of variation ranged from 4.9 to 14.4%. Similar results were obtained for liver tissue from 5 to 20 ppb; coefficients of variation ranged from 1.2 to 9.1 %.
Determination of MCPA, Bromoxynil, 2, 4-D, Trifluralin, Triallate, Picloram, and Diclofop-Methyl in Soil by GC-MS Using Selected Ion Monitoring
Authors: Bruns Gary W , Nelson Susan , Erickson Dennis G 
Published: February 2020

Abstract
A double space extraction procedure was developed to simultaneously determine neutral herbicides (trifluralin, dlclofop- methyl, and triallate) and acid herbicides (MCPA, 2,4-D, bromoxynil, and picloram) in soil. The method uses capillary column gas chromatography (GC) and mass spectrometry (MS) detection with a high degree of confidence in the interpretation of herbicides in many soil types to the 0.003 ppm level. Detection limits at these low levels are possible because extracts can be concentrated by a factor of 50 with few coextractlve interferences evident in the chromatography. Recovery data are excellent for both groups of herbicides (81.5-97.8%, average); relative standard deviations vary from 15-23% because of a larger response variation using GC/MS detection.
Anodic Polarographic Determination of Acetylenic Hypnotics Ethinamate and Methylpentynol Carbamate in Dosage Forms
Authors: Belal F 
Published: February 2020

Abstract
The polarographic behavior of ethinamate and methylpentynol carbamate was studied. Both drugs developed anodic waves in a supporting electrolyte composed of 1M sodium hydroxide and methanol (9 + 1). The relation between the limiting current and the concentration was rectilinear over the range 2.5 X 10-5-2.5 X 10-4M for both drugs. The characteristics of the waves were studied, and a model of the electrode reaction was suggested. The proposed method was successfully applied to the determination of the 2 drugs in their dosage forms, and the results were in agreement with those obtained with published methods.
Chemical Derivatization Analysis of Pesticide Residues. Part XI. An Improved Method for the Determination and Confirmation of Acidic Herbicides in Water
Authors: Lee Hing-Biu , Peart Thomas E , Carron John M , Tse Hung 
Published: February 2020

Abstract
A procedure for the determination and confirmation of acidic herbicides In water Is described. This method is applicable to 13 commonly used herbicides, including the monochlorinated ones, at μg/L and sub-μg/L levels. The water sample is acidified to pH &lt; 2 and extracted by dichloromethane. The herbicides are converted into their pentafluorobenzyl (PFB) derivatives and the products are cleaned up on a silica gel column. A gel permeation cleanup using a Bio-Beads S-X3 column is included to remove the PFB esters of fatty acids, which are the major Interferences in the final analysis using electron capture detection (ECD). Confirmation of herbicides employing electron Impact and negative ion chemical lonlzatlon/ mass spectrometry (NICI/MS) is discussed and applied to river water samples. The mean recoveries of herbicides for water samples fortified at 1 and 0.1 μg/L range from 45 to over 90%. The detection limit of herbicides in natural water samples is 0.05 μg/L with ECD and 0.02 μg/L with NICI/MS.
Separation and Determination of Diesel Contaminants in Various Fish Products by Capillary Gas Chromatography
Authors: Newton J M , Rothman Barry S , Walker F Ann 
Published: February 2020

Abstract
A semiquantitative capillary column gas chromatographic method Is described for the determination of diesel fuel contamination in various canned seafood products. The diesel contaminants are separated from the fish sample by steam distillation, with little carry-over of interfering intrinsic materials such as fish oils. The diesel fuel is extracted from the condensate with n-hexane, and the extract is analyzed on an SPB-1 fused silica capillary column. The efficiency of recovery of diesel fuel added to canned seafood at levels of 40-400 ppt ranged from 72 to 102%. With the additional step of concentrating the hexane extract, the sensitivity of this procedure may be increased at least 10-fold. This procedure can detect the differences among diesel fuel grades No. 1,2, and 5, and variations within diesel grade No. 2, and thus may be useful in determining the type of petroleum contaminants present in various canned fish products.
Determination of Methyl 2-Benzimidazolecarbamate
in Blueberries by Competitive Inhibition Enzyme Immunoassay
Authors: Bushway Rodney J , Ugabalasooriar Jasotha , Perkins Lewis B , Harrison Robert O , Young Barbara E S , Ferguson Bruce S 
Published: February 2020

Abstract
A polyclonal enzyme Immunoassay (EIA) method was developed that will quantitate methyl 2- benzlmidazolecarbamate (MBC), the degradation product of benomyl, In blueberries. The entire analysis Is completed within 25 min, and up to 8 samples can be analyzed simultaneously with a detection limit of 18 ppb. The assay response was linear from 0.69 to 22 ppb MBC. Cross-reactivity was confined to the benzimidazole and dicarboxlm- Ide type pesticides. Intra-assay percent coefficients of variation (% CVs) ranged from 3.4 to 18.4 for the standards, and from 3.2 to 20.6 for the samples. Interassay % CVs varied from 7.5 to 22.3 for the standards, and from 7.5 to 22.0 for the samples. Correlation coefficient between immunoassay and liquid chromatography was 0.87 for the methanol extract and 0.98 for the methylene chloride partition of the methanol extract containing 100 mL 1% sodium chloride. None of the 40 field samples analyzed approached the tolerance of 15 ppm (mean of 20 positive samples was 55 ppb). The ability of the EIA to monitor MBC easily and Inexpensively at concentrations far below the tolerance has major implications for current dietary risk assessment methods.
Matrix Solid-Phase Dispersion Extraction and Liquid Chromatographic Determination of Nicarbazin in Chicken Tissue
Authors: Schenck Frank J , Barker Steven A , Long Austin R 
Published: February 2020

Abstract
This method outlines the necessary steps for the isolation and determination of the drug nicarbazin in chicken liver and muscle tissue. Tissue samples were blended with octadecylsilyl-derivatized silica packing material (C18). A column made from the C18-tissue matrix is first washed with hexane, and then the 4,4-dinitrocarbanilide (DNC) portion of the nicarbazin complex is eluted with acetonitrile. After further cleanup using alumina cartridge chromatography, DNC is determined by reversed-phase liquid chromatography with UV detection at 340 nm. Recoveries based on DNC were 95.8 and 83.7% from liver and muscle tissues, respectively. This method and a classical ethyl acetate extraction method gave comparable results on 4 chicken liver and 3 muscle samples that contained incurred nicarbazin residues. C18 sorbents from different manufacturers as well as lipophilic sorbents other than ds were also studied. The proposed extraction and cleanup procedure requires less than 30 mL solvent, fewer sample manipulations, and does not require solvent partitioning or backwashing of extracts. This combination of characteristics makes this method more attractive than classical isolation procedures for nicarbazin.
Bleaching of Methylene Blue as an Index of Lipoxygenase Activity
Authors: Toyosaki Toshiyuki 
Published: February 2020

Abstract
An assay of lipoxygenase activity was developed that depends on measurements of the time needed for the bleaching of methylene blue to begin. This time was inversely related to the level of lipoxygenase activity (y = 114.5132 - 0.0132x; r= -0.99); it was not affected by the concentration of methylene blue, linoleic acid, or hydroperoxide. Lipoxygenase activity can be calculated from the time needed for the bleaching of methylene blue to begin.
Liquid Chromatographic Confirmatory Method for Five Sulfonamides in Salmon Muscle Tissue by Matrix Solid-Phase Dispersion
Authors: Reimer Gerry J , Suarez Agripina 
Published: February 2020

Abstract
A reversed-phase (C18) liquid chromatographic (LC) method was developed for the analysis of 5 sulfonamides (sulfadiazine [SDZ], sulfamerazine [SMRZ], sulfamethazine [SMTZ], sulfadimethoxine [SDMX], and sulfapyridine [SP]) in salmon muscle tissue. Spiked tissue samples were extracted by matrix solid-phase dispersion. The LC mobile phase gradient consisted of acetonitrile-aqueous 0.01M ammonium acetate (pH 5.5). The potentiators trimethoprim and ormetoprim were also resolved with this chromatographic system. The method detection limits at the 99% confidence level were 48,66,228, and 150 ppb for SP, SMRZ, SMTZ, and SDMX, respectively, and approximately 100 ppb for SDZ. The average percent recoveries of analytes from salmon muscle tissue were 66,66,71,82, and 75% for SDZ, SP, SMRZ, SMTZ, and SDMX, respectively
Survey of Bottled Drinking Water Sold in Canada. Part 2. Selected Volatile Organic Compounds
Authors: Page B Denis , Conacher Henry B S , Salminen John , Nixon Gerald R , Riedel Gunther , Mori Brian , Gagnon Jacques , Brousseau Robert 
Published: February 2020

Abstract
Selected volatile organic compound (VOC) contaminants were determined in 182 samples of retail bottled waters purchased in Canada. Samples included spring water (86) packaged in containers of polyethylene or in smaller containers of transparent plastic or glass, mineral water (61) packaged only in transparent plastic or glass, and miscellaneous bottled waters (35). Analyses were performed by 3 laboratories, each using headspace sampling and capillary gas chromatography with either mass spectrometric (1 laboratory) or flame ionization detection with mass spectrometric confirmation, if required (2 laboratories). Benzene, the contaminant of primary interest, was detected in only 1 of the 182 samples at 2 μg/kg. Other VOC contaminants detected (number of positive samples, average, and range of positives in μg/kg) included toluene (20,6.92,0.5-63), cyclohexane (23, 39.2,3-108), chloroform (12,25.8,3.7-70), and dichloromethane (4,59,22-97). Cyclohexane was found in the plastic and as a migrant from the plastic in 20 samples of spring water, but it was found in only 1 of 61 mineral water samples analyzed at only 3 μg/kg. Chloroform was found almost exclusively in samples that could have been obtained from public water supplies. It was not found in mineral water samples, but it was found in 1 spring water sample at 3.7 μg/kg. The source of the toluene contamination was not known. Other VOCs detected include ethanol and limonene, associated
U.S. Food and Drug Administration Survey of Methyl Mercury in Canned Tuna
Authors: Yess Norma J 
Published: February 2020

Abstract
Methyl mercury was determined by the U.S. Food and Drug Administration (FDA) in 220 samples of canned tuna collected in 1991. Samples were chosen to represent different styles, colors, and packs as available. Emphasis was placed on waterpacked tuna, small can size, and the highest-volume brand names. The average methyl mercury (expressed as Hg) found for the 220 samples was 0.17 ppm; the range was &lt;0.10-0.75 ppm. Statistically, a significantly higher level of methyl mercury was found in solid white and chunk white tuna than was found in chunk light and chunk tuna. Methyl mercury level was not related to can size. None of the 220 samples had methyl mercury levels that exceeded the 1 ppm FDA action level.