bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimized, One-Step, Recovery-Enrichment Broth for Enhanced Detection of Listeria monocytogenes in Pasteurized Milk and Hot Dogs
Authors: Knabel Stephen J 
Published: February 2020

Abstract
A one-step, recovery-enrichment broth, optimized Penn State University (oPSU) broth, was developed to consistently detect low levels of injured and uninjured Listeria monocytogenes cells in ready-to-eat foods. The oPSU broth contains special selective agents that inhibit growth of background flora without inhibiting recovery of injured Listeria cells. After recovery in the anaerobic section of oPSU broth, Listeria cells migrated to the surface, forming a black zone. This migration separated viable from nonviable cells and the food matrix, thereby reducing inhibitors that prevent detection by molecular methods. The high Listeria-to-background ratio in the black zone resulted in consistent detection of low levels of L. monocytogenes in pasteurized foods by both cultural and molecular methods, and greatly reduced both false-negative and false-positive results. oPSU broth does not require transfer to a secondary enrichment broth, making it less laborious and less subject to external contamination than 2-step enrichment protocols. Addition of 150mM d-serine prevented germination of Bacillus spores, but not the growth of vegetative cells. Replacement of d-serine with 12 mg/L acriflavin inhibited growth of vegetative cells of Bacillus spp. without inhibiting recovery of injured Listeria cells. oPSU broth may allow consistent detection of low levels of injured and uninjured cells of L. monocytogenes in pasteurized foods containing various background microflora.
Determination of Tiamulin in Type C Medicated Swine Feeds Using High Throughput Extraction with Liquid Chromatography
Authors: Moore Douglas B , Britton Nancy L , Smallidge Robert L , Riter Ken L 
Published: February 2020

Abstract
An improved method for extraction and analysis of tiamulin is presented to address issues that arose during routine analysis of Type C medicated swine feeds under the current U.S. Food and Drug Administration-Center for Veterinary Medicine (FDA-CVM) approved method. The issues included the need for higher sample throughput and the ability to accommodate a wider variety of feed matrixes. Changes to the FDA-CVM approved method include reduced sample size and solvent volumes, phosphate buffering of tartaric acid, centrifugation, and use of a new liquid chromatography column and adjusted mobile phase composition. A paired sample study was performed to compare performance of the new and existing methods. The paired sample study showed no statistical difference between sample means of paired sets of 17 samples analyzed by both methods (t = 1.95 at 0.05 significance level, p = 0.068). A recovery study showed the method precision to be 2.06% (coefficient of variation) with an average standard recovery of 95.8%. Ruggedness test results indicated good overall ruggedness of the method.
Comparison of Microbial Receptor Assay and Liquid Chromatography for Determination of Penicillin G and Amoxicillin in Milk Powder
Authors: Anderson Kevin L , Lyman Roberta L , Moats Wlliam A , Hansen Arthur P , Rushing John E 
Published: February 2020

Abstract
A microbial receptor assay (Charm II Tablet Beta-Lactam Test) and liquid chromatography (LC) were compared for determination of penicillin G (PG) and amoxicillin (AMOX) in reconstituted milk powder. Nonfat dry milk and whole dry milk were reconstituted (10%, w/v) to concentrations of 0, 2.5, 5, 7.5, and 10 ppb PG; nonfat dry milk was reconstituted (10%, w/v) to 0, 7.5, 10, and 15 ppb AMOX. Reconstituted samples were analyzed blindly by each method. Concentrations determined by both methods demonstrated good agreement. A significant difference between methods (p ≤ 0.05) was observed only for 7.5 ppb PG in defatted dry milk. Significant differences were not observed between known concentrations and concentrations determined by the Charm II assay for PG or AMOX in defatted dry milk and PG in whole dry milk. Results by LC showed significant differences (p ≤ 0.05) between known and measured concentrations at 10 ppb PG in both milks and 0 ppb AMOX in defatted dry milk. These results suggest that both the microbial receptor assay and LC may be useful for determination of PG and AMOX near safe level and tolerance, respectively, in reconstituted milk powder.
Determination of Niacin in Infant Formula by Solid-Phase Extraction/Liquid Chromatography: Peer-Verified Method Performance–Interlaboratory Validation
Authors: LaCroix Denis E , Wolf Wayne R , Chase G William 
Published: February 2020

Abstract
This paper reports the results of the interlaboratory peer validation study of AOAC Peer-Verified Method (PVM) 1:2000 for the determination of niacin in infant formula by solid-phase extraction/liquid chromatography. We have used a Data Quality Objectives (DQO) approach to address not only method variability and robustness but also accuracy of data through the use of an appropriate reference material in conjunction with the interlaboratory validation study. Our DQO included the following: (1) statistical agreement of analytical results and quantitative recovery between 2 collaborating laboratories; (2) the repeatability relative standard deviation (RSDr) values and the HORRAT (Horwitz ratio) obtained (1.07), which satisfied the criteria of the Horwitz “limits of acceptability” at the analyte level present; (3) validation of lack of interference; and (4) accuracy agreement within assigned values for a certified reference material. National Institute of Standards and Technology Standard Reference Material (NIST SRM) 1846 Infant Formula, with a certified value of 63.3 ± 7.6 μg/g for niacin content, was used as a test material for collaborative study and accuracy assessment. Niacin values obtained by the originating laboratory were 59.7 ± 4.0 μg/g (95% confidence interval [CI] = 1.4 μg/g with a relative standard deviation [RSD] of 6.7%) and by the peer laboratory were 56.6 ± 6.6 μg/g (95% CI = 4.1 μg/g, with an RSD of 11.7%). Statistical evaluation using the means equivalence test showed that nicotinic acid values obtained by the peer laboratory were equivalent to those values obtained by the originating laboratory. Linear calibration curves and quantitative recovery were obtained. Integration of the PVM process with a readily available certified reference material gives the user confidence in the accuracy of the data generated by the method through traceability to the reference material used.
Pesticide Residues in Agricultural Products Monitored in Hyogo Prefecture, Japan, FYs 1995–1999
Authors: Akiyama Yumi , Yoshioka Naoki , Tsuji Masahiko 
Published: February 2020

Abstract
During a 5-year monitoring survey (April 1995–March 2000) of pesticide residues in agricultural products, 765 samples (478 domestic; 287 imported) collected in Hyogo Prefecture, Japan, were analyzed. The number of pesticides tested increased from 107 in fiscal year (FY) 1995 to 204 in FY 1999. The purpose of the study was to promote consumer safety by excluding the food illegally containing pesticide residues from markets. Overall, 51% of domestic and 32% of imported samples contained no detectable residues. Multiple residues were detected in 152 (32%) of domestic and 146 (51%) of imported samples. The limit of quantitation was set at 0.01 μg/g and the limit of detection was 0.001 μg/g. Most of the residues were present at low concentrations; 70% of detections in domestic samples were &lt;0.05 μg/g, and 97% were &lt;0.5 μg/g. Although 86% of antifungal agent residues in imported citrus fruits were ≥ 0.1 μg/g, 59% of the other residues in imported samples were &lt;0.05 μg/g, and 96% were &lt;0.5 μg/g. Violations of maximum residue limits (MRL) were observed in 3 samples: diazinon in chrysanthemums, dieldrin in cucumbers, and bitertanol in bananas. Of the detectable residues above 0.01 μg/g, 55% in domestic and 38% in imported samples were &lt;10% of the MRL. Of all the samples, 2.4% contained more than 5 different pesticides; tomatoes, strawberries, apples, and citrus fruits tended to have more multiple residues.
Differential Pulse Polarographic Determination of Lead in Complex Materials after Adsorption of Its N-Methylethylxanthocarbamate Complex on Microcrystalline Naphthalene or on NMethylethylxanthocarbamate–Benzyldimethyltetradecylammonium–Naphthalene Adsorbent
Authors: Hussain Mohammad Farid , Sangahi Anil Kumar , Ahmad Iqbal , Puri Bal Krishan 
Published: February 2020

Abstract
Lead is quantitatively adsorbed as the lead N-methylethylxanthocarbamate (MEXC)–benzyldimethyltetradecylammonium (BDTA) ion pair complex on microcrystalline naphthalene in the pH range 4.0–11.0. The metal is desorbed with HCl and determined by differential pulse polarography. Alternatively lead can be quantitatively adsorbed on the adsorbent (MEXC–BDTA–naphthalene) packed in a column at a flow rate of 1–2 mL/min and determined similarly. Dissolved oxygen is removed by adding a few milliliters of 4% NaBH4 solution. The detection limit is 0.12 μg/mL at the minimum instrumental settings (signal-to-noise ratio, 2). Linearity was obtained over the concentration range 0.3–20.0 μg/mL with a correlation factor of 0.9998 and a relative standard deviation of ± 0.98%. Various parameters, such as the effect of pH, volume of aqueous phase, flow rate, and the interference of a large number of metal ions and anions, were studied in detail to optimize the conditions for the trace determination of lead in various standard alloys, standard biological materials, and environmental samples.
Preparation of Samples for Gas Chromatography/Mass Spectrometry Analysis of Phthalate and Adipate Esters in Plasma and Beverages by Steam Distillation and Extraction
Authors: Kato Kayoko , Yoshimura Yoshihiro , Nakazawa Hiroyuki , Ito Yuko , Oka Hisao 
Published: February 2020

Abstract
Phthalate and adipate esters are present in relatively large amounts in the environment, resulting in their large blank values at analysis and making precise analysis difficult. We developed a highly sensitive analytical method for phthalate and adipate esters in plasma and beverages by lowering the blank values that interfere with analysis. The method uses a closed distillation cleanup system in which steam distillation and extraction are performed simultaneously. The recoveries from beverages and plasma were both satisfactory, ranging from 90.2 to 118.3%, relative standard deviation (RSD) = 2.8–5.3%, and 96.2–134.4%, RSD = 2.2–6.5%, respectively. The detection limits of dibutyl phthalate and di-2-ethyl hexyl phthalate were 5 ng/mL, and those of diethyl phthalate, butyl benzyl phthalate, and di-2-ethyl hexyl adipate were 10 ng/mL in rabbit plasma and beverages.
Detection Methods and Performance Criteria for Genetically Modified Organisms
Authors: Bertheau Yves , Diolez Annick , Kobilinsky André , Magin Kimberly 
Published: February 2020

Abstract
Detection methods for genetically modified organisms (GMOs) are necessary for many applications, from seed purity assessment to compliance of food labeling in several countries. Numerous analytical methods are currently used or under development to support these needs. The currently used methods are bioassays and protein- and DNA-based detection protocols. To avoid discrepancy of results between such largely different methods and, for instance, the potential resulting legal actions, compatibility of the methods is urgently needed. Performance criteria of methods allow evaluation against a common standard. The more-common performance criteria for detection methods are precision, accuracy, sensitivity, and specificity, which together specifically address other terms used to describe the performance of a method, such as applicability, selectivity, calibration, trueness, precision, recovery, operating range, limit of quantitation, limit of detection, and ruggedness. Performance criteria should provide objective tools to accept or reject specific methods, to validate them, to ensure compatibility between validated methods, and be used on a routine basis to reject data outside an acceptable range of variability. When selecting a method of detection, it is also important to consider its applicability, its field of applications, and its limitations, by including factors such as its ability to detect the target analyte in a given matrix, the duration of the analyses, its cost effectiveness, and the necessary sample sizes for testing. Thus, the current GMO detection methods should be evaluated against a common set of performance criteria.
Validation Studies and Proficiency Testing
Authors: Anklam Elke , Heinze Petra , Kay Simon , Eede Guy van den , Popping Bert 
Published: February 2020

Abstract
Genetically modified organisms (GMOs) entered the European food market in 1996. Current legislation demands the labeling of food products if they contain &lt;1% GMO, as assessed for each ingredient of the product. To create confidence in the testing methods and to complement enforcement requirements, there is an urgent need for internationally validated methods, which could serve as reference methods. To date, several methods have been submitted to validation trials at an international level; approaches now exist that can be used in different circumstances and for different food matrixes. Moreover, the requirement for the formal validation of methods is clearly accepted; several national and international bodies are active in organizing studies. Further validation studies, especially on the quantitative polymerase chain reaction methods, need to be performed to cover the rising demand for new extraction methods and other background matrixes, as well as for novel GMO constructs.
Predictions for Rapid Methods and Automation in Food Microbiology
Authors: Fung Daniel Y C 
Published: February 2020

Abstract
A discussion is presented on the present status of rapid methods and automation in microbiology. Predictions are also presented for development in the following areas: viable cell counts; real-time monitoring of hygiene; polymerase chain reaction, ribotyping, and genetic tests in food laboratories; automated enzyme-linked immunosorbent assay and immunotests; rapid dipstick technology; biosensors for Hazard Analysis Critical Control Point programs; instant detection of target pathogens by computer-generated matrix; effective separation and concentration for rapid identification of target cells; microbiological alert systems in food packages; and rapid alert kits for detecting pathogens at home.
Simultaneous Determination of Estradiol and Medroxyprogesterone Acetate in Pharmaceutical Formulations by Second-Derivative Spectrophotometry
Authors: Toral M Inés , Soto César , Richter Pablo , Tapai Ana E 
Published: February 2020

Abstract
This paper reports a simple and fast method for the simultaneous determination of estradiol (ED) and medroxyprogesterone acetate (MP) in pharmaceutical formulations by second-derivative spectrophotometry. Methanol was used to extract the drugs from formulations, and subsequently the extracts were evaluated directly by derivative spectrophotometry. The drugs were determined simultaneously by using the graphic method at 297.4 nm for ED and the zero-crossing method at 273.4 nm for MP. If both compounds are present together in a sample, it is possible to quantitate one in the presence of the other. The best signal-to-noise ratio was found when the second derivative of the spectrum was used. The linear ranges for determination of the drugs were 4.7 × 10−6 to 1.6 × 10−4 and 7.2 × 10−6 to 2.0 × 10−4 mol/L for ED and MP, respectively. The ingredients commonly found in commercial pharmaceutical formulations do not interfere with the determination. Chemical and spectral variables were optimized for the determination of both analytes. Good levels of repeatability (relative standard deviation), 1.4 and 1.9%, were obtained for ED and MP, respectively. The proposed method was applied to the determination of these drugs in pharmaceutical formulations.
French Laboratory Proficiency Testing Program for Food Microbiology
Authors: Augustin Jean-Christophe , Carlier Vincent 
Published: February 2020

Abstract
The proficiency testing program in food microbiology (Réseau d' Analyses et d'Echanges en Microbiologie des Aliments; RAEMA), created in 1988, currently includes 440 participating laboratories. The program establishes proficiency in detection of Salmonella and Listeria monocytogenes, as well as quantitation of aerobic microorganisms, Enterobacteriaceae, coliforms, Escherichia coli, Clostridium perfringens, coagulase-positive Staphylococcus, and Listeria monocytogenes. Twice a year, 5 test samples are sent to participants to assess their precision and trueness for enumeration and detection of microorganisms. Results show an increasing involvement of food microbiology laboratories in quality assurance programs and use of standard and validated analytical methods. However, the percentage of laboratories obtaining questionable and unsatisfactory microbiological results remains relatively onstant.
Determination of Brevetoxins in Shellfish by the Neuroblastoma Assay
Authors: Truman Penelope , Stirling David J , Northcote Peter , Lake Robin J , Seamer Catherine , Hannah Donald J 
Published: February 2020

Abstract
A neuroblastoma assay for determination of brevetoxins in shellfish was developed together with a method for sample cleanup that allows separation of brevetoxins from most of the components that cause matrix interference in the assay. This improved assay method was applied to a range of shellfish samples with different characteristics. Extracts of naturally contaminated and nontoxic shellfish together with extracts spiked with known amounts of toxin were tested. The results demonstrated that brevetoxins could be reliably detected in shellfish extracts at concentrations below the regulatory limit. Brevetoxin activity was detected in 15 of 23 samples from 5 separate toxicity incidents in which shellfish tested positive in the neurotoxic shellfish poisoning (NSP) mouse bioassay. Twelve of these positive NSP results came from 2 toxicity incidents. Yessotoxin was the major contributor to toxicity in 2 other incidents, although some samples contained both yessotoxin and brevetoxin. The sample from the remaining incident contained an unidentified toxin bioactivity, together with gymnodimine. In contrast to earlier versions of the neuroblastoma assay, gymnodimine was not detected by this modified method.
Novel Reference Molecules for Quantitation of Genetically Modified Maize and Soybean
Authors: Kuribara Hideo , Shindo Yoichiro , Matsuoka Takeshi , Takubo Ken , Futo Satoshi , Aoki Nobutaro , Hirao Takashi , Akiyama Hiroshi , Goda Yukihiro , Toyada Masatake , Hino Akihiro 
Published: February 2020

Abstract
New quantitation methods based on a real-time polymerase chain reaction (PCR) technique were developed for 5 lines of genetically modified (GM) maize, including MON810, Event176, Bt11, T25, and GA21, and a GM soy, Roundup Ready. Oligonucleotide DNA, including specific primers and fluorescent dye, labeled probes, were designed for PCRs. Two plasmids were constructed as reference molecules (RMs) for the detection of GM maize and GM soy. The molecules contain the DNA sequences of a specific region found in each GM line, universal sequences used in various GM lines, such as cauliflower mosaic virus 35S promoter and nopaline synthase terminator, and the endogenous DNA sequences of maize or soy. By using these plasmids, no GM maize and GM soy were required as reference materials for the qualitative and quantitative PCR technique. Test samples containing 0, 0.10, 0.50, 1.0, 5.0, and 10% GM maize or GM soy were quantitated. At the 5.0%level, the bias (mean–true value) ranged from 2.8 to 19.4% and the relative standard deviation was &lt;5.2%. These results show that our method involving the use of these plasmids as RMs is reliable and practical for quantitation of GM maize and GM soy.
Temperature-Sensitive Resolution of cis- and trans-Fatty Acid Isomers of Partially Hydrogenated Vegetable Oils on SP-2560 and CP-Sil 88 Capillary Columns
Authors: Ratnayake W M Nimal , Plouffe Louise J , Pasquier Elodie , Gagnon Claude 
Published: February 2020

Abstract
This study examines the effect of the column operating temperature of 100 m SP-2560 and CP-Sil 88 capillary gas chromatographic (GC) columns on the separation of cis- and trans-octadecenoic (18:1) isomers in partially hydrogenated vegetable oils. The overlapping GC peaks were measured at column isothermal temperatures of 170, 175, 180, 185, and 190°C. With both columns, isothermal operation at 180°C produced the fewest overlapping peaks of the cis and trans isomers. At this temperature, all trans-18:1 isomers, except 13t-18:1 (t = trans), 14t-18:1, and 15t-18:1 isomers were resolved from 14t-18:1, the cis-18:1 isomers. The peaks of the 13t-18:1 and 14t-18:1 isomer pair, which always elute together, overlapped peaks of the 6c-18:1 (c = cis), 7c-18:1, and 8c-18:1 isomers; the peak of the 15t-18:1 isomer overlapped the major cis-18:1 peak, which was mainly due to 9c-18:1. Isothermal operations above or below 180°C produced some additional overlapping problems. At 185 and 190°C, the peaks of the 16t-18:1 and 13c-18:1 isomers overlapped. At 175 and 170°C, the 16t-18:1 peak overlapped the 14c-18:1 peak, and the peaks of the 13t + 14t-18:1 isomer pair partially overlapped the major cis-18:1 peak. The separation of 11c-20:1 and α-linolenic acid and its geometric isomers was also affected by the column operating temperature. Isothermal operation of the SP-2560 column at 180°C produced a baseline separation of 11c-20:1 and α-linolenic acid and its geometric isomers, whereas with the CP-Sil 88 column the best resolution was obtained at 170°C. The results of this study show that the SP-2560 capillary column has a slight advantage over the CP-Sil 88 column for the simultaneous resolution of all the fatty acids generally found in partially hydrogenated vegetable oils.
Validation of Real-Time PCR Analyses for Line-Specific Quantitation of Genetically Modified Maize and Soybean UsingNew Reference Molecules
Authors: Shindo Yoichiro , Kuribara Hideo , Matsuoka Takeshi , Futo Satoshi , Sawada Chihiro , Shono Jinji , Akiyama Hiroshi , Goda Yukihiro , Toyoda Masatake , Hino Akihiro ,   Collaborators:, Asano T , Hiramoto M , Iwaya A , Jeong S I , Kajiyama N , Kato H , Katsumoto H , Kim Y M , Kwak H S , Ogawa M , Onozuka Y , Takubo K , Yamakawa H , Yamazaki F , Yoshida A , Yoshimura T 
Published: February 2020

Abstract
Novel analytical methods based on real-time quantitative polymerase chain reactions by use of new reference molecules were validated in interlaboratory studies for the quantitation of genetically modified (GM) maize and soy. More than 13 laboratories from Japan, Korea, and the United States participated in the studies. The interlaboratory studies included 2 separate stages: (1) measurement tests of coefficient values, the ratio of recombinant DNA (r-DNA) sequence, and endogenous DNA sequence in the seeds of GM maize and GM soy; and (2) blind tests with 6 pairs of maize and soy samples, including different levels of GM maize or GM soy. Test results showed that the methods are applicable to the specific quantitation of the 5 lines of GM maize and one line of GM soy. After statistical treatment to remove outliers, the repeatability and reproducibility of these methods at a level of 5.0% were &lt;13.7 and 15.9%, respectively. The quantitation limits of the methods were 0.50% for Bt11, T25, and MON810, and 0.10% for GA21, Event176, and Roundup Ready soy. The results of blind tests showed that the numerical information obtained from these methods will contribute to practical analyses for labeling systems of GM crops.