bluuebunny/crossref_metadata_2025_split huggingface dataset:
Urea Enzymatic Dialysis Procedure for Determination of Total Dietary Fiber
Authors: Jeraci Joseph L , Lewis Betty A , Peter J , Soest Van J , Robertson James B 
Published: February 2020

Abstract
A method that uses urea and enzymes for determination of total dietary fiber (TDF) in foods has been developed and compared with the AOAC enzymatic-gravimetric method (43.A14-43.A20). In the evaluation, results for crude protein and ash contamination were higher by the AOAC method, particularly for samples that form gels during ethanol precipitation. The new urea enzymatic dialysis (UED) method quantitatively recovered, with less variation, more of the purified and semipurified dietary fiber products. TDF recoveries for carboxymethylcellulose and locust bean gum were 98% (SD 3.3) and 95% (SD 6.1) by the AOAC method and 99% (SD 1.0) and 100% (SD 0.6) by the UED method, respectively. The UED method was the more effective in removing starch. For kale samples, starch recovery was 3.5 and 0.2% from TDF residues obtained using the AOAC and UED methods, respectively. Differences were not significant among replicate values for determination of TDF in foods by the UED method (P &gt;0.01). Preliminary studies suggest that the new method can separately determine soluble and insoluble dietary fiber. The data indicate that the UED method is more precise and accurate than the AOAC method.
Evaluation of Various Methods for Measurement of Pectin Content in Jam
Authors: Lane Ralph H , Phillips John G 
Published: February 2020

Abstract
Substitution of toluene for benzene as part of the titration medium specified in the AOAC method for fat acidity (14.069-14.071) was evaluated by 3 laboratories. Blind duplicate samples of 5 commercially available flours were extracted with petroleum ether. The extracts were evaporated to dryness and dissolved in the titration medium containing equal volumes of 95% alcohol and benzene or toluene. Samples were then titrated with standard KOH to the end point of phenolphthalein. The data obtained showed no difference (P &gt; 0.05) between the 2 solvents with respect to fat acidity means. The range of values for repeatability and reproducibility for both solvents was similar. These data indicate that toluene may replace the more toxic benzene. This change has been adopted as a revision in method 14.069-14.071.
Rapid Bacteriological Screening of Cosmetic Raw Materials by Using Bioluminescence
Authors: Nielsen Peter , Dellen Eric Van 
Published: February 2020

Abstract
Incoming cosmetic raw materials are routinely tested for microbial content. Standard plate count methods require up to 72 h. A rapid, sensitive, and inexpensive raw material screening method was developed that detects the presence of bacteria by means of ATP (bioluminescence). With a 24-h broth enrichment, the minimum bacterial ATP detection threshold of 1 cfu/g sample can be achieved using purified firefly luciferin-luciferase and an ATP releasing reagent. By using this rapid screen, microbiologically free material may be released for production within 24 h, while contaminated material undergoes further quantitative and identification testing. In order for a raw material to be validated for this method it must be evaluated for (I) a potential nonmicrobial light-contributing reaction resulting in a false positive or, (2) degradation of the ATP giving a false negative, and (J) confirmation that the raw material has not overwhelmed the buffering capacity of the enrichment broth. The key criteria for a rapid screen was the sensitivity to detect less than one colony forming unit per g product, the speed to do this within 24 h, and cost efficiency. Bioluminescence meets these criteria. With an enrichment step, it can detect less than one cfu/g sample. After the enrichment step, analysis time per sample is approximately 2 min and the cost for material and reagents is less than one dollar per sample.
Combination of Total Solids Determined by Oven Drying and Fat Determined by Mojonnier Extraction for Measurement of Solids-Not-Fat Content of Raw Milk: Collaborative Study
Authors: Clark Jenny L , Barbano David M , Dunham Chapman E 
Published: February 2020

Abstract
Each of 9 laboratories analyzed 9 pairs of blind duplicate raw milk samples for fat, using the Mojonnier ether extraction method (16.E13-16.E17), and for total solids, using a new direct forced air oven method. Solids-not-fat was determined by subtracting percent fat from percent total solids. The solids-not-fat content of the samples tested in the collaborative study ranged from 8.48 to 9.36%. The average repeatability standard deviation (sr) and the average reproducibility standard deviation (sR) for the solids-not-fat method were 0.019 and 0.041, respectively. Average repeatability (RSDr) and reproducibility (RSDR) relative standard deviations were 0.218 and 0.466%, respectively. The mean repeatability value (r) was 0.055; the mean reproducibility value (R) was 0.117. The difference between milk total solids determined by direct forced air oven drying and milk fat determined by Mojonnier ether extraction has been approved for interim official first action for determination of solids-not-fat content of milk.
Alternative Methods for Infrared Analysis of Fat in Milk: Interlaboratory Study
Authors: Biggs Delmar A , Mckenna David 
Published: February 2020

Abstract
A study in 3 laboratories has demonstrated that accuracy of infrared analysis of fat in milk can be improved relative to results by AOAC method 16.083-16.092 by measuring IR absorption by CH2 and CH3 groups in fat molecules instead of or in addition to measuring absorption by carbonyl groups. Theoretical implications for alternative choices of measurements for fat analysis are discussed, and data are presented to indicate the agreement between theory and practice. Mathematical formulas developed from the Beer-Lambert law are presented to describe mechanisms for dual wavelength, double beam, and single beam optical arrangements. A mathematical description of circuitry for these arrangements is included. Methods for multiple linear regression estimates of calibration parameters are discussed. Comparison data indicate optimum situations regarding frequency of calibration and random selection of calibration samples. With optimum control of calibration parameters, mean bias for randomly chosen check samples was reduced to &lt;0.01%. Standard deviation of difference for fat estimates was reduced to range from 0.026 to 0.034%. Quality control procedures and calibration techniques for individual instruments are described. The use of the Fat B filter and a combination of the Fat A and Fat B filters has been adopted official first action as a revision in method 16.083-16.092.
Modified Liquid Chromatographic Method for Determination of Gentian Violet in Animal Feed
Authors: Martinez Elizabeth E , Shimoda Wilbert 
Published: February 2020

Abstract
A mination of Gentian Violet (GV) in animal feed. The reliable detection limit is 0.5 ng (reference standards), and 1 ppm GV was reliably determined in feed. The calibration curve was linear between 1 and 40 μg/mL. The method, developed in a study by the National Center for Toxicological Research, was modified to use methanol-water (9 + 1) instead of benzene-methanol as the eluting solution in the column cleanup. GV is extracted from feed with methanol-lN HC1 (99 + 1), cleaned up on a Sephadex LH-20 column to remove any remaining interferences, separated on a Nova-Pak C18 column fitted with a precolumn filter, and determined at 588 nm. The identity of GV is confirmed by thin-layer chromatography (R4 = 0.47) by comparison with a reference standard. Average recoveries from 3 sets of 5 feed samples containing 2.5, 5.0, and 10.0 ppm GV were 115, 95, and 102%, respectively.
Development and Validation of New Analytical Method for Acrolein in Air
Authors: Yasuhara Akio , Dennis Jason K , Shibamoto Takayuki 
Published: February 2020

Abstract
A new method was developed to determine vapor-phase acrolein in air samples. Air containing vapor-phase acrolein was purged into impingers filled with a dichloromethane solution of JV-methylhydrazine. The resulting derivative, l-methyl-2-pyrazoline, was analyzed by gas chromatography using a nitrogen-phosphorous detector (NPD). The detection limit was 8.9 pg 1-methyl-2-pyrazoline, equivalent to 5.9 pg acrolein. The recovery efficiencies of vapor-phase acrolein were 98.0 ± 2.9% and 100.3 ± 3.1% for 150 and 15 μg, respectively. This method was satisfactorily applied for determination of acrolein formed from various heated fats. The amounts of acrolein formed in a headspace were 109 μg/L from lard, 164 Mg/L from corn oil, 5.1 μg/L from cotton seed oil, and 163 μg/L from sunflower oil.
Liquid Chromatographic Determination of Epimerization of Chlortetracycline Residue to 4-epi-Chlortetracycline Residue in Animal Feed, Using Mcllvain's Buffer as Extractant
Authors: Martinez Elizabeth E , Shimoda Wilbert 
Published: February 2020

Abstract
A method for studying Mcllvain's solution as a factor in epimerization of chlortetracycline in animal feed has been developed. Mcllvain's solution (McBuffer) was used previously to extract oxytetracycline (OTC), tetracycline-HCl (TC-HC1), and chlortetracycline- HC1 (CTC-HC1) from animal feed because it gave the best recoveries for all 3 tetracyclines; however, the McBuffer solution caused epimerization of CTC-HC1 to 4-epi-chlortetracycline (4-epi-CTC). Recovery results were 30-40% lower for CTC than for OTC and TC from the same sample extract. The levels of concentration tested for CTC and 4-epi-CTC were 10 ppm, the detection limits for both were 3 ppb, and the calibration curves were linear between 5 and 80 ppm for both CTC-HC1 and 4-epi-CTC. The present study shows that CTC recoveries averaged 35% lower because of epimerization initiated by the use of McBuffer in the extraction procedure.
Mechanical Extraction of Available Phosphorus in Fertilizers
Authors: Trimm Joe R 
Published: February 2020

Abstract
A system is described for the extraction of available P205 in fertilizers by mechanically adding water and citrate to a glass cell that contains a ceramic filtering frit. Both water and citrate extractions are performed in the cell. The system can be operated manually or automatically. Samples tested included those from the Magruder and the Association of Florida Phosphate Chemists check sample programs for 1987. For all determinations, the values obtained with the mechanized system were within 1 standard deviation of the average AOAC value reported for each sample.
Effect of Gelatin on Recovery of Hair Fragments in Filth Analysis
Authors: Beavin Bernice B 
Published: February 2020

Abstract
Prior literature has recommended the use of gelatin capsules or gelatin film for transferring spike elements to samples being examined for recovery studies. It was believed that gelatin had no effect on the recovery of filth spike elements. However, this study shows that hair recovery is lower when gelatin is present in direct trap-off procedures. Two types of gelatin capsules, gelatin film, and strips of filter paper were used to transfer spike filth elements. A comparison study employing an acid digestion and wet sieving procedure was also performed and showed that gelatin had little or no effect on the recovery of hairs using this type of procedure. An additional test was performed using gelatin added to water containing the same type of spiked filth elements. No hair fragments were recovered but all insect fragments were recovered. All recovery studies were performed using only water in the liquid phase of the trap flask extractions, with mineral oil or heptane as the flotation medium. No food product was used.
Spectrophotometric Determination of Some Benzene Sulfonamides with 7,7,8,8-Tetracyanoquinodimethane
Authors: Mohamed Abdel-Maboud I 
Published: February 2020

Abstract
A new spectrophotometric method for the determination of some unsubstituted benzene sulfonamides is presented. The method is based on the interaction of these derivatives with 7,7,8,8-tetracyanoquinodimethane at pH 9.0-9.5 to produce intense blue products. The quantitation of the products was carried out at 578 nm. Beer’s law was obeyed over a wide range of concentrations for all sulfonamide compounds studied. Optimum analytical conditions were determined, and the color produced was stable for at least 90 min at 25 °C. Analytical data for determination of sulfonamide compounds in pure form are presented together with application of the proposed method for analysis of some commercially available pharmaceutical preparations. The results are in good agreement with those obtained by official procedures.
Detection of Pork and Lard as Adulterants in Processed Meat: Liquid Chromatographic Analysis of Derivatized Triglycerides
Authors: Saeed Tala , Ali Sadika G , Rahman Hani Abdul A , Sawaya Wajih N 
Published: February 2020

Abstract
A new method is described for detection of pork and lard as adulterants in processed beef and mutton mixtures. The unsaturated triglycerides in the fat are ozonized and then derivatized. The mixture of derivatized and saturated triglycerides is analyzed by liquid chromatography using a reverse-phase column and a UV detector. Pork fat has larger amounts of triglyceride containing saturated fatty acid at the C-2 position than does the fat of other meat. The ratio of triglyceride containing saturated fatty acid vs triglyceride containing unsaturated fatty acid at the same (C-2) position (SSU/SUS) in a sample is compared with those of pure meats. The presence of pork in the sample causes the ratio to increase compared with ratios for pure beef or mutton. The increase in the SSU/SUS ratio is significant for the addition of 1% pork in beef. In the case of mutton, the addition of 3% pork causes a noticeable change. The method is reliable and is also applicable to samples containing only fat. Processing (heating or cooking) does not affect the ratios.
Simplified Extraction and Cleanup for Multiresidue Determination of Pesticides in Lanolin
Authors: Diserens Henri 
Published: February 2020

Abstract
In the proposed method, a light petroleum solution of lanolin (wool fat) is adsorbed on diatomaceous earth in an Extrelut® column, and the pesticides are eluted with acetonitrile saturated with light petroleum. After evaporation to a small volume, the extract is subjected to solid-phase extraction (SPE) on a C-18 column. The acetonitrile eluate is evaporated to dryness and the residue is taken up in light petroleum. Organophosphorus pesticides are determined by temperature- programmed gas chromatography (GC) on a wide-bore column using a flame photometric detector in the phosphorus mode. Organochlorine pesticides are determined after miniaturized Florisil cleanup by classic GC on an OV-17/QF-1 packed column, using an electron capture detector. This procedure is more rapid and straightforward than the time-consuming AOAC extraction method, 29.014. Cleanup was better and the results obtained were comparable. Recoveries for 13 organochlorine and organophosphorus pesticides, frequently found in lanolin, ranged from 80 to 90%
Determination of Organic Arsenicals in Pesticide Formulations by Ion Chromatography
Authors: Gehrig Connie C , Fitzpatrick Timothy M 
Published: February 2020

Abstract
The organic arsenicals, cacodylic acid and methanearsonic acid and their salts, are determined in pesticide formulations by ion chromatography. The samples are diluted in the aqueous mobile phase, injected directly into the chromatograph, and determined by nonsuppressed ion chromatography. Analysis time is less than 5 min for each arsenical. The method was tested for precision, linearity, and recovery. Linearity of the methanearsonic acid gave regression and correlation coefficients of 0.9998 and 0.9999, respectively, and 0.9997 and 0.9998 for cacodylic acid. Quadruplicate analyses of 5 methanearsonic acid samples gave relative standard deviations of 0.833-3.10. Quadruplicate analyses of 4 cacodylic acid samples gave relative standard deviations of 0.648-1.41. Recovery was 100.3 ± 3.6%.
Methodology for the Analysis of Benzimidazole Anthelmintics as Drug Residues in Animal Tissues
Authors: Barker Steven A , Mcdowell Tamera , Charkhian Bahram , Hsieh Lily C , Short Charles R 
Published: February 2020

Abstract
Methodology for the analysis of 8 benzimldazoles as residues in bovine liver is reported. Spiked tissues were extracted by homogenlzation in saline and ammonium hydroxide and blending with diatomaceous earth. This matrix was packed Into a column, and the benzimldazoles were eluted with ethyl acetate. After the sample was further purified, benzimldazoles were separated and quantitated by liquid chromatography with ultraviolet detection (290 nm). Liver tissue samples obtained from cattle which had undergone a drug depletion study of fenbendazole administered per os were analyzed using these methods. The results of these analyses and the application of this approach to multiresidue analysis of drugs in animal tissues are discussed.
Colorimetric Determination of Hydroxyproline as Measure of Collagen Content in Meat and Meat Products: NMKL Collaborative Study
Authors: Kolar Kurt 
Published: February 2020

Abstract
A colorimetric method for the determination of hydroxyproline as a measure of collagen in meat and meat products has been collaboratively studied in 18 laboratories. The method includes hydrolysis with sulfuric acid, oxidation with chloramine- T, and formation of a reddish purple complex with 4- dimethylaminobenzaldehyde. Five frozen and 3 freeze-dried samples were tested, ranging in content from 0.11 to 0.88% and from 0.39 to 4.0% hydroxyproline, respectively. The mean values of 2 identical samples were 0.245 and 0.251 %. The average recovery from a spiked sample was 96.1 %. The hydroxyproline content of a known sample (a mixture of 2 samples in the ratio 5:2) was calculated to 1.42%, which agrees well with the analytical result, 1.40%. In comparison with other collaborative studies, based on the ISO analytical method, the repeatability and reproducibility of this method agree well with the other results. This method was accepted as an official NMKL method by all national Committees, and has been adopted official first action by AOAC as an NMKLAOAC method.
Outlier Detection in Collaborative Studies
Authors: Kelly Patrick C 
Published: February 2020

Abstract
Extended tables of critical values for the reduction In standard deviation tests for single and paired outliers recommended for collaborative studies are presented. Critical values for the single outlier test are derived mathematically and those for the paired test are derived from computer simulations. The single outlier test becomes more and more stringent as the size of the study increases. A confidence Interval approach Is suggested as a means to treat all sizes of collaborative studies in a uniform manner.
Determination of Zearalenone and Related Metabolites in Porcine Urine by Modified Enzyme-Linked Immunosorbent Assay
Authors: Macdougald Ormond A , Thulin Andrew J , Pestka James J 
Published: February 2020

Abstract
A direct competitive enzyme-linked immunosorbent assay (ELISA) was modified for the determination of zearalenone and zearalenols in porcine urine. In the modified procedure, standard or unknown concentrations of zearalenone were added to all wells, followed by rapid addition of zearalenonehorseradlsh peroxidase conjugate, whereas in previous methods, zearalenone and zearalenone-horseradish peroxidase were mixed and then added to microtiter wells. The modification increased the number of urine samples that could be analyzed per assay. The linear portion of the modified ELISA standard curve covered the range of 10-500 ng zearalenone/mL. Average recovery of zearalenone from spiked urine was 91,101,95,107,136,112, and 120% for 1, 10, 25, 50, 100, 250, and 500 ng zearalenone/mL urine, respectively. Mean within-assay coefficient of variation for each concentration of zearalenone in 5 standard curves was 5.95%. Between-assay coefficients of variation for concentrations of zearalenone equivalents in lower and upper regions of the standard curve were 10.9% (n = 18) and 8.8% (n = 20), respectively. Analysis of urine samples showed that a gilt excreted 5.3% of ingested zearalenone in the 8 h following ingestion, with an average excretion rate of about 100 /ug zearalenone equivalents/h.
Effects of Injection Solvent and Mobile Phase on Efficiency in Reverse-Phase Liquid Chromatographic Determination of Aflatoxin M1
Authors: Beaver Rodney W 
Published: February 2020

Abstract
The effects of Injection solvent and mobile phase composition on the reverse-phase liquid chromatographic determination of aflatoxin M1 (M1) were examined. M1 was converted to the more highly fluorescent derivative aflatoxin M2a (M2a)- Using a C-18 column and a mobile phase of H20-MeCNMeOH (60 + 20 + 20) (MP-A), M2a was dissolved in various ratios of MeCN-H20 prior to Injection. Chromatographic efficiency for the M2a peak varied from ca 2000 theoretical plates when injected in 30% aqueous MeCN to ca 9000 plates when injected in water alone. However, using the same C-18 column but with a mobile phase of H20-IPAMeCN (80 + 12 + 8) (MP-B), the M2a peak exhibited 25000 plates when injected in 30% aqueous MeCN and 10000 plates when injected in water alone.
Studies in Adapting the Modified Comprehensive Method for Fertilizer Nitrogen to Block Digestion/Steam Distillation
Authors: Kane Peter , Fitzpatrick Tim 
Published: February 2020

Abstract
A high temperature heating block has been successfully used as an alternative apparatus to traditional Kjeldahl digestion for methods involving various organic nitrogen samples. But the block has not been successfully used for a fertilizer nitrogen methodology. This paper describes an attempt to adapt the AOAC modified comprehensive method for fertilizer nitrogen to the block, followed by steam distillation and titration. A wide variety of reduction conditions were found satisfactory to reduce the N03- nitrogen from KN03. More rigorous digestion parameters, a 450°C block temperature, higher than normal salt/acid ratios, and air condensers to contain the digestion acid were found necessary to achieve full nitrogen recovery from lysine*HCI. The remaining hindrance to a successful fertilizer nitrogen block methodology is that a chromium NH4 + complex found in the digests requires about 30 min to be broken down during the steam distillation step. This is not practical for routine analysis.
Diastatic Activity of Forage Additive Products Containing Malt Flour
Authors: Alli Inteaz , Dilollo Antonio , Kermasha Selim , Thiffault Christine , Dumais Francean 
Published: February 2020

Abstract
A method has been developed for the measurement of diastatic activity of forage additive products which contain malt flour as active ingredient. The procedure Involves extraction of the enzyme activity with calcium chloride solution, Incubation of the extract with excess soluble starch, and measurement of the unhydrolyzed starch by the starch-iodine reaction. The conditions established for optimum enzyme activity were 1 % calcium chloride solution for enzyme extraction, and enzyme-starch reaction pH and temperature of pH 5.5 and 40 °C, respectively. With the combination of these experimental conditions, the diastatic activity, expressed as g starch hydrolyzed per g material per h (SKB) (a) of malt diastase was 75.9 SKB units, (b) of malt flour was 32.8 SKB units, and (c) of 2 forage additive products were 0.205 SKB unit and 0.044 SKB unit.