bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liquid Chromatographic Determination of Glyphosate and Aminomethylphosphonic Acid (AMPA) in Environmental Water: Collaborative Study
Authors: Oppenhuizen Mark E , Cowell John E 
Published: February 2020

Abstract
A new method for determination of glyphosate and amlnomethylphosphonlc acid (AMPA) residues In environmental water was collaboratively studied by 6 laboratories. The method Is simpler and shorter than previous methods. A filtered volume of water is evaporated to dryness and the residue Is dissolved In a buffered EDTA solution. Glyphosate and AMPA are determined by liquid chromatography with postcolumn reaction detection. The method was validated over the range 0.50-5000 ppb, although one of the collaborating laboratories could not reliably quantltate below 1.0 ppb. Statistical analysis of the results showed that typical reproducibility relative standard deviations (RSDR) ranged from 11 to 20% for both glyphosate and AMPA, which compares very well with predicted values for this concentration range. Total variability (as measured by sR) Increased with increasing fortification level. The method has been adopted official first action by AOAC.
Development and Validation of a Method for Determining Elements in Solid Waste Using Microwave Digestion
Authors: Binstock David A , Grohse Peter M , Gaskill Alvia , Sellers Charles , Kingston H M , Jassie Lois B 
Published: February 2020

Abstract
A microwave-assisted method for preparing samples for determination of elements In solid waste has been developed (draft EPA Method 3051). Validation of the sample preparation method was performed through a collaborative study to determine its precision and accuracy. Fifteen independent laboratories digested 4 National Institute of Standards and Technology (NIST) standard reference materials (SRMs) and 1 solvent recovery waste in duplicate. Digestates were analyzed for 19 elements using inductively coupled plasma (ICP) emission spectroscopy. The precision and bias of the method were evaluated. When compared with an open vessel hot-plate digestion method (SW-846 Method 3050), the microwave method produced similar analytical results with better overall precision. Bias for the 1 sample that allowed this determination was found to be excellent.
Methods for Assay, Related Substances, and Organic Volatile Impurities in Triazolam Raw Materials and Formulations
Authors: Beaulieu Normand , Cyr Terry D , Graham Susan J , Lawrence Robert C , Sears Roger W , Lovering Edward G 
Published: February 2020

Abstract
Liquid chromatographic methods have been developed for determination of triazolam and related compounds in drug raw materials and tablets. The methods resolve 9 available related compounds from the drug with quantitation limits of 0.1 % or less. Eight raw materials and 16 formulations were examined for related compounds. Total impurities in raw materials ranged up to 0.6% and up to 1% in formulations, not including a compound in some tablets that is believed to be excipient related. Assay values were between 99.9 and 101.3% for raw materials and between 89.4 and 105.5% for tablets. A gas chromatographic method was developed for organic volatile Impurities in drug raw materials. The major solvents found were methyl ethyl ketone (100-750 ppm), ethyl acetate (510 ppm), and n-propanol (80-300 ppm), with a trace of benzene (&lt;30 ppm) in several samples.
New Microbiological Method for Determining Spectinomycin in Pelleted and Meal Feeds Using Trifluoroacetic Acid as Primary Extractant
Authors: Stahl Gerald L , Zaya Matthew J , Paulissen Jerome B 
Published: February 2020

Abstract
A new microbiological method, Identified as the spectinomycin trifluoroacetic (SPE-TFA) method, was compared with the current AOAC method for analyzing spectinomycin in meal and pelleted feeds fortified with LS-20™ premlx. Feeds containing 3 concentrations of drugs and a zero level were tested in a correlation study. The data showed no significant differences in the percent of theory assayed between meal and pelleted samples using the SPE-TFA method, but the percent of theory found using the AOAC method was significantly lower for the pelleted samples than for the meal samples. The within-sample variation of the AOAC assay was also not the same for all samples; the SPE-TFA assay variation was relatively constant for all samples. The SPETFA method produced an overall average recovery of 98% with a range of 89-109% compared with an 85% recovery ranging from 64 to 102% for the AOAC method. In addition to producing better recoveries, the SPE-TFA method features a more sensitive response line, and final test solutions have viscosities and clarity more comparable to the standard solutions than those produced by the current AOAC method
Determination of Food Contamination by Mineral Oil from Jute Sacks Using Coupled LC-GC
Authors: Grob Konrad , Lanfranchi Mauro , Egli Jnes , Artho Anna 
Published: February 2020

Abstract
Jute fibers are treated with about 5-7% of a high boiling mineral oil fraction ("batching oil") to render them flexible for making fabrics. Foods transported in jute bags are contaminated by this batching oil. A method involving automated on-line LC-GC is described for determining these hydrocarbons in various foods. Complete transfer of the LC fraction to GC is presupposed for obtaining the required sensitivity. Results are given for nuts, coffee, cocoa products, and rice. Contamination ranged between about 5 and 500 ppm.
Continuous Flow Vapor Generation for Inductively Coupled Argon Plasma Spectrometric Analysis. Part 2. Arsenic
Authors: Tracy Mark L , Littlefield Sue E , Möller Gregory 
Published: February 2020

Abstract
Total arsenic Is determined by Inductively coupled plasma atomic emission using hydride vapor generation. A 1 g sample is wet ashed in a 16 X 150 mm 10 mL volumetric test tube on a programmed heating block with nitric, sulfuric, and perchloric acids at up to 310 °C. After treatment with hydrochloric acid and potassium iodide, arsenic Is reduced by sodium borohydride to arsine In a simplified continuous flow manifold. A standard pneumatic nebulizer effects the gasliquid separation of AsH3, which is quantified by ICP atomic emission at 193.756 nm. The instrument detection limit for the method has been determined to be 0.4 μg/L. For a 10:1 dilution of a nominal 1 g sample, the detection limit is 4 μg/kg and the linear range Is up to 4 mg/kg. Recoveries from 3 matrixes were 99-104%, with a typical RSD of 2%. The method has demonstrated statistical control for samples of biological interest and is especially well suited to analysis of small samples.
A Resuscitation/Selection System for Rapid Determination of Salmonella in Foods
Authors: Martin Alain , Katz Stanley E 
Published: February 2020

Abstract
A resuscitation medium was developed consisting of a trypticase soy broth base supplemented with 0.5% yeast extract, 0.25% sodium pyruvate, 0.01% sodium thioglycollate, and 0.1% chicken fat. After a resuscitation period of 4 h, the medium was made selective by addition of either sodium thiosulfate, bile salts and iodine, or sodium selenite and Lcystine. The now selective medium was incubated for 16 h. The presence or absence of Salmonella was determined by the Salmonella-Tek antibody-based detection kit. The present system was compared with a method of the Bacteriological Analytical Manual(BAM) for naturally contaminated foods. Nineteen egg products were screened; 3/19 were positive using the BAM method, 9/19 were positive using the present system. Seventeen chicken samples were assayed; 10/17 were positive using the BAM method; 13/17 were positive using the present system. Of 8 pepper samples, 4/8 were positive using the BAM method; 6/8 were positive using the present system. Of 8 spice samples, 6/8 were positive using the BAM method, 7/8 were positive using the present system. Of 6 onion products sampled, 5/6 were positive using the BAM method; 6/6 were positive using the present system.
Liquid Chromatographic Determination of the Processing Aid 4-Hexylresorcinol in Shrimp
Authors: King Joan M , McEvily Arthur J , Iyengar Radha 
Published: February 2020

Abstract
A rapid, sensitive, liquid chromatographic (LC) method has been developed for determination of residuals of the processing aid, 4-hexylresorcinol, on shrimp meat. An aqueous homogenate of shrimp meat is extracted with ethyl acetate followed by precolumn preparation on a silica Sep-Pak cartridge. LC determination is preformed with a Nova-Pak C18 column, with UV detection at 214 nm. Sensitivity was 0.006 μg, and recovery from shrimp meat samples of known 4-hexylresorcinol addition was 94%. Shrimp treated with 4-hexylresorcinol under the recommended dip protocol had mean residuals of 1.18 ppm, with a standard deviation of 0.13 ppm.
Assay of Oxolinic Acid Residues in Salmon Muscle by Liquid Chromatography with Fluorescence Detection: Interlaboratory Study
Authors: Carignan Germain , Larocque Lyse , Stephen Sved ,   Collaborators:, Carrier K , Ikai Y , Reimer G , Schermerhorn P G , Zitko V 
Published: February 2020

Abstract
A previously developed method that uses a simplified sample preparation and fluorometric detection of liquid chromatographic eluates for the determination of oxolinic acid in salmon muscle has been collaboratively studied. Five laboratories participated in the study to analyze, in quintuplicate, blank salmon muscle fortified at 10, 20, 50, and 100 μg/kg (ppb), and 2 incurred samples from salmon given feed with medicated oxolinic acid. The tissue, 2 g mixed with 2 g Na2S04, is extracted with ethyl acetate and centrifuged, and the solvent Is evaporated. The residue is partitioned in a mixture of hexane and 0.01 M oxalic acid, and the aqueous phase is chromatographed using fluorescence detection at 327 nm excitation and 369 nm emission. Mean recoveries ranged from 77.2 to 84.5% in spiked samples with reproducibility relative standard deviation (RSDR) ranging from 11.5 to 18.3%. Treated salmon were found to contain 8.71 and 53.8 μg/kg with RSDR of 18.6 and 16.7%, respectively. The corresponding repeatability relative standard deviations (RSDr) were 5.8-12.2%, and 7.7 and 6.2%. The method is recommended for regulatory purposes in Canada.
A New Approach to the Study of Glucosinolates by Isocratic Liquid Chromatography. Part I. Rapid Determination of Desulfated Derivatives of Rapeseed Glucosinolates
Authors: Quinsac Alain , Ribaillier Daniel , Elfakir Claire , Lafosse Michel , Dreux Michel 
Published: February 2020

Abstract
Liquid chromatographic (LC) analysis of desulfated derivatives of rapeseed glucosinolates has been carried out under isocratic elution conditions with different CN-bonded stationary phases. The effects of the eluant composition (water, acetonitrile, and methanol) with the stationary phase (Zorbax CN, Lichrospher CN, and Ultrasphere CN) and temperature (20 and 50°C) are described. An isocratic LC method performed at room temperature using a Lichrospher CN column and water as mobile phase is proposed. The chromatographic analysis can be done in less than 12 min, and it is easier and less expensive than the traditional gradient mode. Four commercial samples of rapeseed containing various quantities of other cruciferous seeds (wild mustard and stinkweed) as an admixture have been analyzed to determine the total giucosinolate content. Relative standard deviations of repeatability of the isocratic and gradient LC methods ranged from 0.4 to 1.7% and from 2.7 to 4.7%, respectively. Comparison of the results showed good agreement between the 2 methods (better than 98%).
Development of a Deer Rapid Identification Field Test (DRIFT) by Modified Agar-Gel Immunodiffusion
Authors: Cutrufelli Mark E , Mageau Richard R , Schwab Bernard , Johnston Ralph W 
Published: February 2020

Abstract
A deer rapid identification field test (DRIFT) has been developed for detection of deer meat (venison) In a wide variety of meat products. The test is an adaptation of previously developed field screening immunodiffusion tests for detection of other individual species. DRIFT was demonstrated to be specific, sensitive, and accurate in the analysis of 100 samples. This test Is especially well suited for use by state officials in charge of game regulations.
Liquid Chromatographic Determination of Flurazepam
Hydrochloride in Bulk Drug and Dosage Forms:
Collaborative Study
Authors: Bargo Eileen S 
Published: February 2020

Abstract
Eleven laboratories collaboratively studied the liquid chromatographic method for determining flurazepam hydrochloride In capsules and bulk drug. The method uses an octadecylsllane reversed- phase column, a mobile phase of methanol- 1% ammonium acetate (80 + 20), and photometric detection at 239 nm. Each collaborator received 8 samples: powdered composites of 5 commercial capsule preparations, each as a blind duplicate pair, and 3 bulk drug samples (1 blind duplicate). The ranges of repeatability and reproducibility relative standard deviations were 0.93-2.46 and 2.42-3.86% for the capsule samples and 0.97 and 1.76-2.27% for the bulk drug samples, respectively. The method was adopted first action by AOAC International.
Graphite Furnace Atomic Absorption Method for the Determination of Chromium in Foods and Biological Materials
Authors: Ihli N J . Miller , Greene F E 
Published: February 2020

Abstract
A method was developed for the determination of chromium in food samples and other biological materials. Samples are dry ashed In a muffle furnace and are analyzed by graphite furnace atomic absorption spectrometry. Magnesium nitrate is used as a matrix modifier, and samples are quantltated by platform atomizatlon and peak area measurements with direct calibration against aqueous standards. The detection limit (based on 3.29 σ) was 5.6 pg, or 0.28 μg/L for a 20 μL injection. The characteristic mass was 3.2 pg. This method was validated by analyzing a range of reference materials and was subsequently used for the analysis of a variety of food samples. A comparison of analytical results obtained from direct calibration and method of additions was made.
Interlaboratory Study of Decreasing the Number of Standard Points in the Official Iron Standard Curve
Authors: Martin James I , Soliman A M 
Published: February 2020

Abstract
An Interlaboratory study was conducted to (1) evaluate the effects of reducing the 10 points for the iron standard curve to 5 points in Official Methods of Analysis (1990) 15th Ed., sees 944.02A-944.02C(a), and (2) compare the levels of Iron found In foods by using the 10-point and 5-point standard curves. The 5 points (0.2, 0.6, 1.0, 1.4, and 1.8 μg Fe/mL) were selected by eliminating every other standard point from the 10-point curve after correction for the reagent blank. No differences in the performance parameters between method versions were found when blind duplicate analysis was used to estimate the performance parameters for each sample analyzed.
Determination of Total, Soluble, and Insoluble Dietary Fiber in Foods—Enzymatic-Gravimetric Method, MES-TRIS Buffer: Collaborative Study
Authors: Lee Sungsoo C , Prosky Leon , Vries Jonathan W De 
Published: February 2020

Abstract
A joint AOAC/AACC (American Association of Cereal Chemists) collaborative study of methods for the determination of soluble, insoluble, and total dietary fiber (SDF, IDF, and TDF) was conducted with 11 participating laboratories. The assay Is based on a modification of the AOAC TDF method 985.29 and the SDF/IDF method collaboratively studied recently by AOAC. The principles of the method are the same as those for the AOAC dietary fiber methods 985.29 and 991.42, Including the use of the same 3 enzymes (heat-stable α-amylase, protease, and amyloglucosldase) and similar enzyme Incubation conditions. In the modification, minor changes have been made to reduce analysis time and to Improve assay precision: (1) MES-TRIS buffer replaces phosphate buffer; (2) one pH adjustment step Is eliminated; and (3) total volumes of reaction mixture and filtration are reduced. Eleven collaborators were sent 20 analytical samples (4 cereal and grain products, 3 fruits, and 3 vegetables) for duplicate blind analysis. The SDF, IDF, and TDF content of the foods tested ranged from 0.53 to 7.17, 0.59 to 60.53, and 1.12 to 67.56 g/100 g, respectively. The respective average RSDR values for SDF, IDF, and TDF determinations by direct measurements were 13.1, 5.2, and 4.5%. The TDF values calculated by summing SDF and IDF were in excellent agreement with the TDF values measured independently. The modification did not alter the method performance with regard to mean dietary fiber values, yet It generated lower assay variability compared with the unmodified methods. The method for SDF, IDF, and TDF (by summing SDF and IDF) has been adopted first action by AOAC International.
Quantitation of Microorganisms in Raw Minced Meat Using the Direct Epifluorescent Filter Technique: NMKL Collaborative Study
Authors: Boisen Flemming , Skovgaard Niels , Ewald Steen , Olsson Gunnar , Wirtanen Gun 
Published: February 2020

Abstract
Fourteen Nordic laboratories participated In an Interlaboratory study of microorganisms In raw minced meat. After 2 preliminary collaborative evaluations of 20 and 6 prepared direct epifluorescent filter technique (DEFT) slides, the equipment and the counting technique were adjusted and standardized. In the following third and final trial, the laboratories examined 10 samples in duplicate. A special model was developed for homogenlzatlon, preservation, and transport of raw minced meat within 24 h. Test microorganisms were those present naturally In the meat. The participating laboratories received Identical samples in duplicate at 10 counting levels. The results Indicated a coefficient of variation of 15% by Interlaboratory counting of 26 prepared DEFT slides. By examining samples of raw minced meat for microorganisms showing any degree of orange fluorescence, the repeatability and the reproducibility were 0.41 and 0.78, respectively. The repeatability standard deviation (sr) was0.14, and the reproducibility standard deviation (SR) was 0.27. The study demonstrated that DEFT Is a dependable method for quantitation of microorganisms in raw minced meat. Precision of DEFT was in agreement with Nordic Committee on Food Analysis standard deviation values used In the Nordic countries for plate-count quality control.
Evaluation of the Color of Some Spanish Unifloral Honey Types as a Characterization Parameter
Authors: Castro R Mateo , Escamilla M Jiménez , Reig F Bosch 
Published: February 2020

Abstract
The color of 7 types of Spanish unifloral honey from rosemary, orange blossom, lavender, eucalyptus, sunflower, heather, and honeydew was Investigated for Its potential use as a characterization parameter. Colors were estimated by visual comparison with a Lovlbond 1000 Instrument, the readings of which were transformed Into Pfund units. As an alternative method, the transmittances of liquid samples at selected wavelengths were measured, trlstlmulus values were calculated, and chromatic coordinates In the CIE-1931 (x,y,L) and CIE-1976 (L*a*b*) color spaces were determined. The correlation coefficient between x and the Pfund grading was 0.958, but visual comparisons proved to be less objective and precise than CIE parameters; yet, analysis by visual comparison can be used by unskilled dealers and beekeepers because of Its great simplicity. A stepwise discriminant analysis revealed that CIE-1976 (L*a*b*) coordinates yield an overall proportion of accurately classified samples slightly better than that afforded by CIE-1931 coordinates (76 vs 71%). However, rosemary and lavender honeys were more accurately classed by using the CIE-1931 system. The results show that color determinations make a useful tool for helping to classify honeys.
Reversed-Phase Liquid Chromatographic Determination of Vitamin D in Infant Formulas and Enteral Nutritionals
Authors: Sliva Matthew G , Green Astor E , Sanders James K , Euber John R , Saucerman Janice R 
Published: February 2020

Abstract
Vitamin D In infant formulas and enteral nutritional products is determined by reversed-phase liquid chromatography (LC) with UV detection. The sample Is saponified 30 mln at 60°C and extracted Into 60 mL hexane. The hexane layer is then washed and evaporated to dryness. The sample Is reconstituted and added to a 3 mL silica solid-phase extraction column. Vitamins D2 and D3 are eluted from the column with 7 mL methylene chlorlde-lsopropanol mixture (99.8 + 0.2). The eluant is evaporated to dryness and reconstituted In 1 mLacetonltrlle. The acetonitrile solution is analyzed on a C18 reversed-phase LC column (25 cm x 4.6 mm, 5 μm particle size) with UV detection at 265 nm. Linearity for this method between 8 and 2600 lU/qt has shown a coefficient of determination of 1.000, with method precision ranging from 1 to 6%. Spike recoveries gave a mean of 99.1%. Because this method can quantitate and distinguish between vitamin D2 and vitamin D3 In products, vitamin D2 is used as an Internal standard In quantltatlng vitamin D3, and vice versa. The method Is applicable to milk-, soy-, and protein hydrolysate-based infant formulas and enteral nutritional products, both liquid and powder. The sample throughput is estimated to be 24 per day. An AOAC collaborative study of this method is recommended.
Analytical Use of Linear Regression. Part I: Regression Procedures for Calibration and Quantitation
Authors: Mactaggart Douglas L , Farwell Sherry O 
Published: February 2020

Abstract
Although commonly used by analysts, linear regression requires careful attention to 5 fundamental assumptions. This paper summarizes these assumptions and describes the effects of deviations from these assumptions and various approaches to correct for such deviations. Specific cases are defined where classical unweighted or weighted linear regression methods are still applicable in calibration experiments, even though the independent x-variable contains random error. Another topic of this paper is the proper construction of confidence intervals, not only for the relatively easy case of predicting a response value given an analyte concentration (or amount) value but also for the theoretically more difficult case of predicting a concentration (or amount) value given a response value. Various approaches based on single-use discrimination intervals (SDI), multiple-use discrimination intervals (MDI), and unlimited-use discrimination intervals (UDI) are discussed for the latter case. This discussion examines both the theory and analytical applicability of each approach. A simplified procedure based on calculated g-values is introduced for guidance on whether or not to use the SDI approximation. The lengths of the MDIs and UDIs are compared for several test data sets, and the modified Scheffe UDI approach is found to be advantageous because of its relative simplicity and short intervals. Its use is recommended when neither of the described SDI approaches is appropriate, i.e., when the comparison of several predicted analyte concentration (or amount) values obtained from the same calibration curve is desired.