bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validation of a Method for the Determination of Multiclass Pesticide Residues in Fruit Juices by Liquid Chromatography/Tandem Mass Spectrometry after Extraction by Matrix Solid-Phase Dispersion
Authors: Perret Daniela , Gentili Alessandra , Marchese Stefano , Sergi Manuel , D'Ascenzo Giuseppe 
Published: July 2020

Abstract
A multiresidue method was developed and validated for the determination of pesticide residues (omethoate, dimethoate, carbendazim, propoxur, thiabendazole, carbaryl, pirimicarb, azinphos-methyl, methidathion, and iprodione) in fruit juices. The samples were extracted by matrix solid-phase dispersion with diatomaceous earth and analyzed by liquid chromatography/tandem mass spectrometry. The method detection limits were &lt;0.2 ppb for all pesticides; the relative standard deviations for analyses of samples fortified over the range of 2–50 ng/g were &lt;9%, and the recoveries for each pesticide were all between 77 and 102%. The proposed method was used to analyze 21 commercial fruit juices; pesticide residues were found in 71% of the samples.
Derivative Spectrophotometric Determination of Nitrate in Plant Tissue
Authors: Lastra Olga C 
Published: July 2020

Abstract
A derivative spectrophotometric method was developed to determine NO3– –N in plant tissues. The method is based on measurement of the first-derivative spectrum of nitrosalicylic acid in basic solution. The nitrosalicylic acid was obtained by reaction of samples with salicylic acid in concentrated sulfuric acid and was used by Cataldo et al. in nonderivative spectrophotometry. The main strength of this technique is the lack of matrix background interference, typical of plant extracts in traditional spectrophotometric methods. This method is fast, inexpensive, easy-to-apply, and highly selective. The calibration graph was linear in the range of 0.1 and 1.0 mg/L N as NO3–. Average recovery in real matrixes (lettuce and spinach) was 102.6%; average standard deviation was 3.3. This method has been applied to leaves of 4 types of lettuce.
Comparison of Cholesterol Oxidation Product Preparation Methods for Subsequent Gas Chromatographic Analysis
Authors: Rodriguez-Estrada Maria Teresa , Costa Arianna , Pelillo Marco , Caboni Maria Fiorenza , Lercker Giovanni 
Published: July 2020

Abstract
An evaluation was made of the stability of cholesterol hydroperoxides (CHPs) under the analytical conditions and preparation methods commonly used for determination and quantification of cholesterol oxidation products (COPs). CHPs were prepared by photoxidation and separated by silica thin-layer chromatography. CHPs were individually collected by normal-phase liquid chromatography and then subjected either to reduction or to cold saponification. The corresponding hydroxyl derivatives were generated by reduction, whereas cold saponification gave rise predominantly to 7-ketocholesterol. In another test, silylated and non-silylated CHPs were separately injected into a gas chromatograph at 310°C, collected, and re-injected into a gas chromatography-mass spectrometry system. The silylated CHPs were more stable than the non-silylated ones, giving 7-ketocholesterol, 7α-and 7β-hydroxycholesterol as main degradation products. Two unknown degradation peaks were detected in both silylated and nonsilylated CHPs, having 384 as main m/z fragment. The study of their mass spectra led to the conclusion that peaks A and B correspond to 6α- and 6β-hydroxycholesterol, respectively.
Diet and Metabolic Syndrome: Where Does Resistant Starch Fit In?
Authors: Tapsell Linda C 
Published: July 2020

Abstract
Metabolic syndrome is a term linking the clinical profiles of some of the world's major health problems today: obesity, heart disease, and diabetes. It is predicated on dietary patterns, and particularly on the delivery of fuel. The effects may be seen first in the development of abdominal obesity and insulin resistance leading to Type 2 diabetes mellitus and coronary heart disease. This review examines the role resistant starch might play in the prevention and management of these conditions. Beginning with a definition of resistant starch, a critical review of the scientific literature is presented. Current knowledge suggests that resistant starch in the diet may assist in the prevention and management of conditions associated with the metabolic syndrome via its potential effects on delaying the delivery of glucose as fuel with subsequent fat utilization and appetite control benefits. There is still a great deal of research to be undertaken in this area, but it is clearly warranted, given the position of starches in the global food supply and the potential impact on population health.
Variation of Analytical Results for Peanuts in Energy Bars and Milk Chocolate
Authors: Trucksess Mary W , Whitaker Thomas B , Slate Andrew B , Williams Kristina M , Brewer Vickery A , Whittaker Paul , Heeres James T 
Published: July 2020

Abstract
Peanuts contain proteins that can cause severe allergic reactions in some sensitized individuals. Studies were conducted to determine the percentage of recovery by an enzyme-linked immunosorbent assay (ELISA) method in the analysis for peanuts in energy bars and milk chocolate and to determine the sampling, subsampling, and analytical variances associated with testing energy bars and milk chocolate for peanuts. Food products containing chocolate were selected because their composition makes sample preparation for subsampling difficult. Peanut-contaminated energy bars, noncontaminated energy bars, incurred milk chocolate containing known levels of peanuts, and peanut-free milk chocolate were used. A commercially available ELISA kit was used for analysis. The sampling, sample preparation, and analytical variances associated with each step of the test procedure to measure peanut protein were determined for energy bars. The sample preparation and analytical variances were determined for milk chocolate. Variances were found to be functions of peanut concentration. Sampling and subsampling variability associated with energy bars accounted for 96.6% of the total testing variability. Subsampling variability associated with powdered milk chocolate accounted for &gt;60% of the total testing variability. The variability among peanut test results can be reduced by increasing sample size, subsample size, and number of analyses. For energy bars the effect of increasing sample size from 1 to 4 bars, subsample size from 5 to 20 g, and number of aliquots quantified from 1 to 2 on reducing the sampling, sample preparation, and analytical variance was demonstrated. For powdered milk chocolate, the effects of increasing subsample size from 5 to 20 g and number of aliquots quantified from 1 to 2 on reducing sample preparation and analytical variances were demonstrated. This study serves as a template for application to other foods, and for extrapolation to different sizes of samples and subsamples as well as numbers of analyses.
Carrier Tests to Assess Microbicidal Activities of Chemical Disinfectants for Use on Medical Devices and Environmental Surfaces
Authors: Springthorpe V Susan , Sattar Syed A 
Published: July 2020

Abstract
For well over a decade, many deficiencies have been identified in current AOAC methods used to assess the microbicidal activities of chemical disinfectants on medical devices and environmental surfaces. This report discusses the development of quantitative carrier tests (QCT) designed to address these concerns. Decontamination of surfaces with dried inocula is invariably more difficult than when microorganisms are in suspension. For medical device as well as environmental decontamination, microbicides are used on contaminated surfaces, thus making it necessary to evaluate their microbicidal action on representative carrier materials contaminated with a dried challenge microorganism(s). Our approach is a 2-tiered QCT. The first tier (QCT-1) uses relatively ideal conditions to assess performance of the microbicide for screening purposes; the test uses smooth glass surfaces and quantities of disinfectant in excess of those likely to be experienced in the field. The second tier of testing (QCT-2) is more stringent because it uses (1) disks of brushed stainless steel as carriers, (2) only 50 μL of the test formulation on each carrier as compared to 1 mL in QCT-1, and (3) an added soil load to simulate the presence of residual body fluids or accumulated surface dirt. This review also discusses the factors that affect disinfection of medical devices and environmental surfaces in the context of the methodology used to evaluate the potency of microbicides. Specific recommendations for discussion are included, and performance criteria are suggested based on a risk-reduction approach for different classes of disinfectants. The focus is on improving the relevance of the test methodology to actual field use of disinfectants for devices and facilities in health care, and potentially in other settings. It is hoped that this review and its recommendations will initiate needed discussion and resolution of the many issues identified.
Reduction of Exposure to Acrylamide: Achievements, Potential of Optimization, and Problems Encountered from the Perspectives of a Swiss Enforcement Laboratory
Authors: Grob Koni 
Published: July 2020

Abstract
The most important initiatives taken in Switzerland to reduce exposure of consumers to acrylamide are the separate sale of potatoes low in reducing sugars for roasting and frying, the optimization of the raw material and preparation of french fries, and campaigns to implement suitable preparation methods in the gastronomy and homes. Industry works on improving a range of other products. Although these measures can reduce high exposures by some 80%, they have little effect on the background exposure resulting from coffee, bread, and numerous other products for which no substantial improvement is in sight. At this stage, improvements should be achieved by supporting voluntary activity rather than legal limits. Committed and consistent risk communication is key, and the support of improvements presupposes innovative approaches.
Rapid and Easy Identification of Illicium verum Hook. f. and Its Adulterant Illicium anisatum Linn. by Fluorescent Microscopy and Gas Chromatography
Authors: Joshi Vaishali C , Srinivas Pullela V , Khan Ikhlas A 
Published: July 2020

Abstract
Illicium verum Hook. f. is used as an herbal tea to treat colic pain in infants. Reports suggest that Star anise herbal tea may be adulterated with Illicium anisatum Linn. A short and rapid method using microscopy and gas chromatography (GC) was developed to detect I. anisatum Linn., an adulterant in the powdered mixture of I. verum. Anatomical differences in the epicarp cells of I. verum and I. anisatum fruits were clearly defined as examined under fluorescent microscopy and scanning electron microscopy. A GC method was developed for quick identification of possible I. anisatum adulteration with I. verum.
Multiresidue Determination of Organophosphorus Pesticides in Ginkgo Leaves by Accelerated Solvent Extraction and Gas Chromatography with Flame Photometric Detection
Authors: Yi Xionghai , Lu Yitong 
Published: July 2020

Abstract
A rapid and simple method using accelerated solvent extraction and solid-phase extraction cleanup was developed and validated for the determination of 15 organophosphorus pesticides in ginkgo leaves by capillary gas chromatography with flame photometric detection. The pesticides were extracted at 100°C under 1500 psi pressure in &lt;20 min. The average recovery from 10 g ginkgo leaves, fortified at 3 levels ranging from 0.05 to 1.00 mg/kg, was 95.2% with a relative standard deviation of 4.6%. The limits of detection ranged from 1.11 × 10−3 mg/kg (dimethoate) to 4.44 × 10−3 mg/kg (dichlorvos). The proposed method showed acceptable accuracy and precision while minimizing environmental concerns, time, and labor. Furthermore, the method could be easily applied to the monitoring of these 15 organophosphorus pesticides in ginkgo leaves.
Flame Atomic Absorption Spectrometric Determination of Trace Amounts of Nickel after Extraction and Preconcentration onto Natural Modified Analcime Zeolite Loaded with 2-(5-Bromo-2-Pyridylazo)-5-Diethylaminophenol
Authors: Afzali Darush , Taher Mohammad Ali , Mostafavi Ali , Mahani Mohammad Khayatzadeh 
Published: July 2020

Abstract
Nickel is a moderately toxic element compared with other transition metals. However, inhalation of nickel and its compounds leads to serious problems, including cancer of the respiratory system and a skin disorder, nickel-eczema. Thus, attention has focused on the toxicity of nickel at low concentrations, and the development of reliable, analytical approaches for the determination of trace amounts of nickel is needed. This paper describes a simple, rapid, and sensitive flame atomic absorption spectrometric method for the determination of trace amounts of nickel in various samples after adsorption of its 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol complex on a modified Analcime column in the pH range of 7.5–10.5. The retained analyte on the Analcime is recovered with 5.0 mL 2M nitric acid and determined by flame atomic absorption spectrometry. The detection limit is 20 ng/mL, and the calibration curve is linear for analyte concentrations in the range of 0.1–8 μg/mL final solution, with a correlation coefficient of 0.9993. Eight replicate determinations of nickel at 2 μg/mL in the final solution gave an absorbance of 0.1222, with a relative standard deviation (RSD) of ±1.2%. The interference of a large number of anions and cations was studied, and the proposed method was used for the determination of nickel in various standard reference samples. The accuracy of the proposed method was evaluated by analyzing standard reference samples, and the results were satisfactory (recoveries of &gt;96%; RSD of &lt;3.5%).
The Impact of Processing on the Nutritional Quality of Food Proteins
Authors: Meade Susie J , Reid Elizabeth A , Gerrard Juliet A 
Published: July 2020

Abstract
During many food processing regimens, food proteins may undergo a variety of chemical modifications. Despite the enormous consumption of processed foods worldwide, much remains to be learned about the exact nature of these modifications. This is partly due to the complex nature of the changes involved, and partly to the problems of analysis imposed by the intractable nature of the food matrix. Such difficulties are compounded by the paucity of chemically based analytical tests that accurately measure amino acid availability in biologically relevant terms. In this review, we explore the known changes that proteins and amino acids undergo during food processing and the consequences of these changes on the physical and nutritional qualities of the food. We also examine the impact of these protein derivatizations for the analysis of food proteins and amino acids, and highlight areas that require future research.
Determination of Residual Clopidol in Chicken Muscle by Capillary Gas Chromatography/Mass Spectrometry
Authors: He Limin , Liu Yahong , Zeng Zhenling , Huang Xianhui , Liu Rong 
Published: July 2020

Abstract
Clopidol was extracted from chicken with acetonitrile, and the extract was evaporated to about 5 mL. The concentrated solution was centrifuged and applied to a glass column filled with basic alumina. The column was eluted with methanol and the methanol was evaporated to dryness. Theresidue was derivatized with Sylon BFT™ and analyzed by gas chromatography/mass spectrometry (GC/MS). Mass characteristics of trimethylsilyl derivative of clopidol were interpreted manually. The selected-ion monitoring mode was performed at m/z 191, 248, 263, and 265. A sensitive, reproducible GC/MS method was developed for monitoring residues of clopidol in chickens. All recoveries of the drug from chicken muscle fortified at 1, 10, and 100 ng/g were &gt;65%, and relative standard deviations were &lt;15%. The detection limit was about 0.5 ng/g, and the quantitation limit was the lower limit of the standard curve, which was about 1 ng/g.
Estimation of Pioglitazone Hydrochloride and Metformin Hydrochloride in Tablets by Derivative Spectrophotometry and Liquid Chromatographic Methods
Authors: Shankar Madhira B , Modi Vaibhav D , Shah Dimal A , Bhatt Kashyap K , Mehta Rajendra S , Geetha Madhira , Patel Binita J 
Published: July 2020

Abstract
Two simple and accurate methods of analysis to determine pioglitazone hydrochloride (PIO) and metformin hydrochloride (MET) in combined dosage forms were developed using second-derivative spectrophotometry and reversed-phase liquid chromatography (LC). PIO and MET in combined preparations (tablets) were quantified using the second-derivative responses at 227.55 nm for PIO and 257.25 nm for MET in spectra of their solutions in a mixture of methanol and acetonitrile (30 + 70). The calibration curves were linear [correlation coefficient (r) = 0.9984 for PIO and 0.9986 for MET] in the concentration range of 8–40 μg/mL for PIO and 4–12 μg/mL for MET. In the LC method, analysis was performed on a Hypersil ODS-C18 column with 5 μm particle size using the mobile phase acetonitrile-water-acetic acid (75 + 25 + 0.3), adjusted to pH 5.5 with liquor ammonia, at a flow rate of 0.5 mL/min. Measurement was made at a wavelength of 230 nm. Both the drugs were well resolved on the stationary phase, and the retention times were 8.5 min for PIO and 16.0 min for MET. The calibration curves were linear (r = 0.9933 for PIO and 0.9958 for MET) in the concentration range of 4–20 μg/mL for PIO and MET. Both methods were validated, and the results were compared statistically. They were found to be accurate, precise, and specific. The methods were successfully applied to the estimation of PIO and MET in combined tablet formulations.
Enumeration of Total Coliforms and E. coli in Foods by the SimPlate® Coliform and E. coli Color Indicator Method and Conventional Culture Methods: Collaborative Study
Authors: Feldsine Philip T , Lienau Andrew H , Roa Nerie H , Green Shannon T ,   Collaborators:, Braut-Taormina J , Braymen C , Chavey C , Cohen A , Deans A , Delancey S , Elems C , Forgey R , Gonzalez E , Hall V , Huang M C J , Humes L , Johnson F , Kerdaji K , King J , Kipker L , Lau D , Nogle J , Peters C , Pinkston J , Porter M , Potter L , Rogers S , Stephens J , Skorupa G , Taylor R , Tuncan E , Vought K , Vrana D 
Published: July 2020

Abstract
The relative effectiveness of the SimPlate® Coliform and E. coli Color Indicator (CEc-CI) method was compared to the AOAC 3-tube Most Probable Number (MPN) methods for enumerating and confirming coliforms and Escherichia coli in foods (966.23 and 966.24). In this study, test portions were prepared and analyzed according to the conditions stated in both the AOAC methods and SimPlate directions for use. Six food types were artificially contaminated with coliform bacteria and E. coli: frozen burritos, frozen broccoli, fluid pasteurized milk, whole almond nut meats, cheese, and powdered cake mix. Method comparisons were conducted. Overall, the SimPlate method demonstrated &lt;0.3 log difference for total coliform and E. coli counts compared to the AOAC reference methods for the majority of food types and levels analyzed. In all cases, the repeatability and reproducibility of the SimPlate CEc-CI method were not different from those of the reference methods and in certain cases, were statistically better than those of the AOAC 3-tube MPN methods. These results indicate that the SimPlate CEc-CI method and the reference culture methods are comparable for enumeration of both total coliforms and E. coli in foods.
Real-Time Determination of Microbial Activity of Pasteurized Fluid Milk Using a Novel Microrespirometer Method
Authors: Ren Zhao , Hsieh Yun-Hwa P 
Published: July 2020

Abstract
The effectiveness of the rapid CO2 evolution rate (CER) method was evaluated by using a novel noninstrumental microrespirometer to determine the microbial activity of pasteurized milk and comparing it with traditional culturing methods in homogeneous milk samples. Three different kinds of milk (skim, 1% fat, and whole) stored at 2 temperatures (4° and 7°C) were measured daily for CER, aerobic plate count (APC), and psychrotrophic bacterial count. The mean initial rates of CO2 evolution for all 3 samples stored at the 2 temperatures ranged from 3.42 to 3.71 μL/h/mL and increased to 29 μL/h/mL and above on the final day of the experiment. Regression analysis showed a high correlation (R = 0.98–0.99) between the APC and CER results in combined milk samples. A cut-off value of CER (25 μL/h/mL) for milk spoilage at refrigeration temperatures was identified. The real-time CER method shows promise as a potential alternative to the traditional culture method.
Determination of Magnesium in Foods by Single-Sweep Polarography
Authors: Xiangchun Zhou , Lirong Wang , Yan Zeng , Guanghan Lu , Peng Zhen 
Published: July 2020

Abstract
In KOH, the Mg(II)bromopyrogallol red (BPR) complex produced a very sensitive polarographic wave at 1.30 V. The wave height was linear with the concentration of Mg(II) in the range of 0.05 to 2 μg/mL. The detection limit was 0.01 μg/mL. The electrochemical behavior of Mg(II)BPR was studied by electrochemical and spectrophotometric methods. Experiments proved that the polarographic wave of Mg(II)BPR was due to the reduction of BPR in the Mg(II)BPR complex. The method, which was sensitive, selective, and simple to perform, was used to determine magnesium in foods, and the results were consistent with those obtained by atomic absorption spectroscopy.
Determination of Nitroimidazole Residues in Porcine Urine by Liquid Chromatography/TandemMass Spectrometry
Authors: Xia Xi , Li Xiaowei , Shen Jianzhong , Zhang Suxia , Ding Shuangyang , Jiang Haiyang 
Published: July 2020

Abstract
A reliable and sensitive method was developed for determination of nitroimidazoles in porcine urine. Sample preparation involves an extraction with ethyl acetate, followed by a solid-phase extraction cleanup step. The final extract is injected into the liquid chromatography/tandem mass spectrometry system in the positive-ion electrospray ionization mode. A C8 column with water and acetonitrile as the mobile phase is used for chromatographic separation under gradient conditions. Overall average recoveries ranged from 83 to 107%. The limits of detection ranged from 0.03 to 0.05 ng/mL, and the limits of quantitation, from 0.1 to 0.2 ng/mL.
Single-Laboratory Validation of a Method for the Determination of Furan in Foods by Using Static Headspace Sampling and Gas Chromatography/Mass Spectrometry
Authors: Nyman Patricia J , Morehouse Kim M , McNeal Timothy P , Perfetti Gracia A , Diachenko Gregory W 
Published: July 2020

Abstract
A headspace gas chromatography/mass spectrometry method was developed and validated in-house for the determination of furan in foods. The method of standard additions with d4-furan as the internal standard was used to quantitate furan. The limit of detection and limit of quantitation (LOQ) values ranged from 0.2 and 0.6 ng/g, respectively, in apple juice to 0.9 and 2.9 ng/g, respectively, in peanut butter. Recoveries were obtained at 0.5, 1, 2, and 3 times the LOQ. At 1, 2, and 3 times the LOQ, the recoveries ranged from 89.4 to 108%, and the relative standard deviations ranged from 3.3 to 17.3% for all the matrixes. For apple juice, chicken broth, and infant formula, the averaged coefficients of determination from the linear regression analyses were &gt;0.99 with each food fortified at 0.5, 1, 2, and 3 times the LOQ. The coefficients of determination were &gt;0.99 for green beans and 0.96 for peanut butter with the foods fortified at 1, 2, and 3 times the LOQ. Within-laboratory precision was determined by comparing the amounts of furan found in 18 samples by 2 analysts on different days with different instruments. For most of the foods, the difference between the amounts found by each analyst was &lt;18%. The method was used to conduct a survey of &gt;300 foods. The furan levels found ranged from none detected to 174 ng/g.