bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Bromide Ion Residues in Broccoli after Fumigation with Methyl Bromide by Nonsuppressed Ion-Chromatography
Authors: Huang Hung-Chang , Lai Shu-Fen , Liu Yung-Chuan , Chen Hon-Yi , Tu Wu-Chun
Published: February 2020

A nonsuppressed ion chromatography method using conductivity detection was performed to determine the concentration of bromide ions in broccoli following fumigation with methyl bromide (MB). After fumigation by MB with concentration up to 40 g/m3, bromide residue (BR) was considerably increased from the trace amount on unfumigated broccoli to about 12 ppm on fumigated broccoli. For probing the location of BR, broccoli was divided into stems and florets. The BRs were measured separately, and the results indicated that BRs only appear in the florets of broccoli.
Determination of Acephate in Human Urine
Authors: LePage Jane T , Hebert Vincent R , Tomaszewska Elizabeth M , Rothlein Joan E , McCauley Linda
Published: February 2020

Acephate is a commonly used organophosphate insecticide applied on agricultural crops and in residential communities. Because very little acephate is metabolized prior to excretion, the parent pesticide compound can be measured in human urine. The residue method must be sensitive enough to determine human exposure and potential health risk for both agricultural workers and their families who may be exposed by pesticide drift or by inadvertent carry-home residues. A reliable and sensitive method was developed to measure acephate concentrations in human urine. Urine was diluted with water and acetone, adjusted to a neutral pH, and partitioned twice in acetone–methylene chloride (1 + 1, v/v), with NaCl added to aid separation. The solvent-reduced organic phase extracts were clarified by activated charcoal solid-phase extraction and then adjusted to a final volume with the addition of a D-xylose analyte protectant solution to reduce matrix enhancement effects. Acephate concentrations in urine were determined by gas chromatography using pulsed flame photometric detection. The method limit of detection was established at 2 μg/L, with a method limit of quantitation of 10 μg/L. The average recovery from urine fortified with 10–500 μg/L was 102 ± 12% (n = 32).
Ion Chromatographic Determination of Nitrate and Nitrite in Vegetable and Fruit Baby Foods
Authors: McMullen Sarah E , Casanova John A , Gross Lois K , Schenck Frank J
Published: February 2020

An ion chromatographic method was developed for the determination of nitrate and nitrite in vegetable and fruit baby foods. The introduction of nitrate or nitrite to food may be natural or artificial as a preservative. Because of the higher pH found in babies' stomachs, nitrate can act as a reservoir for the production of nitrite by nitrate-reducing bacteria that can be harbored in the intestinal tract. This problem does not exist in adults because of the lower pH of the adult stomach. Exposure to nitrite by infants can result in methemoglobinemia (blue baby syndrome). There are also indications that carcinogenic nitrosamines can be formed from nitrates at the higher pH. These gastric conditions disappear at approximately 6 months of age. In this method, nitrate and nitrite were separated on a hydroxide-selective anion exchange column using online electrolytically generated high-purity hydroxide eluant and detected using suppressed conductivity detection. Average recoveries of spiked nitrite residue ranged from 91 to 104% and spiked nitrate residue ranged from 87 to 104%. This method and the AOAC Official Method yield comparable results for samples containing incurred nitrate residue. In addition, this method eliminates the hazardous waste associated with the use of cadmium found in the AOAC Official Method.
Application of a Fast High-Performance Liquid Chromatography Method for Simultaneous Determination of Furanic Compounds and Glucosylisomaltol in Breakfast Cereals
Authors: RufiÁN-Henares JosÉ A , Delgado-Andrade Cristina , Morales Francisco J
Published: February 2020

The high-performance liquid chormatography method reported in the present paper provides a fast, low-cost, precise, and simple technique to analyze simultaneously 3 different indicators of nonenzymatic browning, i.e., hydroxymethylfurfural (HMF), furfural, and glucosylisomaltol (GIM), in breakfast cereals. These compounds were extracted in aqueous solution and separated on a reversed-phase C18 column with wateracetonitrile (95 + 5, v/v) mobile phase under isocratic conditions. Average recovery rates for HMF, furfural, and GIM were 99.1, 98.4, and 99.4%, respectively. The coefficients of variation were 3.67, 2.42, and 1.59% for HMF, furfural, and GIM, respectively. The detection limit was 0.01mg/kg, and the quantitation limit was 0.05mg/kg for the 3 studied compounds.
Effect of Sample Preparation and Preenrichment Media on the Recovery of Salmonella from Cantaloupes, Mangoes, and Tomatoes
Authors: Hammack Thomas S , Johnson Mildred L , Jacobson Andrew P , Andrews Wallace H
Published: February 2020

Studies were conducted to determine the relative effectiveness of buffered peptone water (BPW), lactose (LAC) broth, and Universal Preenrichment (UP) broth for the recovery of Salmonella organisms from fruit rinses, whole fruit, and comminuted fruit. In the first phase, the relative effectiveness of the rinse and soak methods for the recovery of Salmonella from surface-contaminated mangoes and tomatoes was examined. Fruits were spot inoculated with single Salmonella serovars and held for 4 days at 26C before analysis was initiated. The contaminated fruit was rinsed in portions of BPW, LAC broth, or UP broth. Portions from each rinse were added to its respective broth (e.g., BPW to BPW). Individual whole fruit, in their remaining broth rinses (soak method), and the fruit rinse/broths (rinse method) were incubated for 24 h at 35C. The Bacteriological Analytical Manual (BAM) Salmonella culture method was followed thereafter. The soak method produced significantly greater numbers (P < 0.05) of positive test portions than did the rinse method for the analysis of mangoes (93 versus 12) and tomatoes (85 versus 34). The 3 broths were comparable for the recovery of Salmonella for both the soak and the rinse methods for mangoes. For tomatoes, there were no significant differences among the broths for the soak method, but BPW and UP broth were significantlymore productive (P < 0.05) than LAC broth by the rinse method. In the second phase, the relative effectiveness of LAC broth, BPW, and UP broth for the recovery of Salmonella from comminuted fruit was examined. Fruits were contaminated with single Salmonella serovars and aged for 4 days at 26C. Twenty 25 g test portions were preenriched in each of the following broths: BPW, LAC broth, and UP broth. The BAM Salmonella culture method was followed thereafter. For cantaloupes, significantly more (P < 0.05) Salmonella-positive test portions were recovered with UP broth (96 Salmonella-positive test portions) and BPW (87 Salmonella-positive test portions) than with LAC broth (57 Salmonella-positive test portions). For mangoes, BPW recovered an arithmetically larger number of Salmonella-positive test portions (27 Salmonella-positive test portions) than did either LAC broth (14 Salmonella-positive test portions) or UP broth (18 Salmonella-positive test portions). For tomatoes, there were no significant differences among the broths: BPW recovered 65 Salmonella-positive test portions, UP broth recovered 62 Salmonella-positive test portions, and LAC broth recovered 60 Salmonella-positive test portions. For the analysis of whole fruit, it is recommended that the soak method be used. For whole fruit analyzed with the soak method, UP broth should be used for tomatoes and BPW should be used formangoes. It is further recommended that UP broth be used for the analysis of comminuted cantaloupes and that BPW be used for the analysis of comminuted mangoes and tomatoes.
Indirect Determination of Fe(III) in Synthetic Samples and Iron Dextran Tablets by Capillary Electrophoresis with Ultraviolet Detection
Authors: Tang Yajun , Wu Mingjia , Xu Yuanhong
Published: February 2020

A capillary electrophoresis method based on the oxidation of ascorbic acid is proposed for the indirect determination of Fe(III). Fe(III) concentration corresponds to the decrease in ascorbic acid peak area. The calibration graph was linear in the range of 1.68112 mg/L for Fe(III), which was easily detected at a concentration of 1.12 mg/L at 3 times the standard deviation of the blank divided by the slope of the calibration graph. The lack of interferences from Fe(II) in synthetic samples and 3 excipients (starch, magnesium strearate, and microcrystalline cellulose) in dextran tablets in the determination of Fe(III) confirmed the high selectivity of the proposed method. Its application to the determination of Fe(III) in several synthetic samples and iron dextran tablets produced excellent results.
Development of Real-Time Polymerase Chain Reaction Assay with TaqMan Probe for the Quantitative Detection of Infectious Hypodermal and Hematopoietic Necrosis Virus from Shrimp
Authors: Yue Zhi-Qin , Liu Hong , Wang Wei-Ji , Lei Zhi-Wen , Liang Cheng-Zhu , Jiang Yu-Lin
Published: February 2020

An assay was developed for the detection of infectious hypodermal and hematopoietic necrosis virus (IHHNV) based on real-time quantitative polymerase chain reaction (PCR). A pair of primers and a TaqMan probe were designed that are specific for the recognition of a conservative region in the IHHNV genome. The IHHNV real-time PCR assay had a detection limit of 9 DNA copies,with a dynamic range of detection between 9 106 and 9 DNA copies. The primer pairs and probe were specific to IHHNV and did not cross-reactwith shrimp genomic DNAor other shrimp viruses such as White Spot Syndrome Virus (WSSV), Monodon Baculovirus (MBV), and hepatopancreatic parvovirus (HPV). This assay has a broad application for basic and clinical investigations. For clinical samples, the real-time PCR assay detected all the positive samples screened by conventional PCR, which indicated the sensitivity of the real-time assay. The IHHNV real-time PCR assay with high sensitivity, specificity, wide range of detection ability, and simplicity is particularly useful for screening large numbers of specimens and measuring viral loads to monitor the broodstock.
Spectrophotometric Determination of Some Antihistaminic Drugs Using 7,7,8,8-Tetracyanoquinodimethane (TCNQ)
Authors: Badawey Amr M , Abbas Samah S , Loutfy Hayam M
Published: February 2020

A simple and sensitive spectrophotometric method is suggested for analysis of 3 antihistaminic drugs, acrivastine (I), mequitazine (II), and dimethindene maleate (III). The method is based on reaction of the drugs with 7,7,8,8-tetracyanoquinodimethane (TCNQ) in acetonitrile to form highly stable colored products that are measured at 750, 766, and 844 nm for I and II, and 480 and 618 nm for III. Beer's law is obeyed in the ranges of 560 g/mL for I, 550 g/mL for II, and 1070 g/mL for III. The optimum assay conditions and their applicability to the determination of the cited drugs in pharmaceutical formulations are described. The method is statistically analyzed as compared with the European Pharmacopoeia (2001) method for the analysis of dimethindene maleate and reference methods for acrivastine and mequitazine drugs revealing good accuracy and precision.
Development and Validation of a New High-Performance Liquid Chromatography Method for the Determination of Gliclazide and Repaglinide in Pharmaceutical Formulations
Authors: Berecka Anna , Gumieniczek Anna , Hopkaa Hanna
Published: February 2020

A new high-performance liquid chromatography method was developed and validated for the quantitation of gliclazide and repaglinide in pharmaceutical formulations. Determination was performed using a LiChroCART RP-18 column, a mobile phase containing acetonitrilephosphate buffer (pH 2.1; 60 + 40, v/v), and ultraviolet (UV) detection at 225 nm. Repaglinide was used as an internal standard for gliclazide determination and gliclazide for repaglinide assay. The method was validated with respect to linearity, precision, robustness, ruggedness, accuracy, and specificity. The calibration graphs ranged from 0.015 to 0.09 mg/mL for gliclazide and 0.06 to 0.36 mg/mL for repaglinide. Intra- and interday relative standard deviation values for the standard solutions were 0.70 and 1.01% for gliclazide and 0.78 and 0.93% for repaglinide, respectively. Total recoveries of gliclazide and repaglinide from the laboratory-prepared mixtures were 99.82 0.58 and 101.50 0.46% for gliclazide and repaglinide, respectively (mean standard deviation (SD)]. In forced degradation studies, the effect of acid, base, oxidation, UV light, and temperature on both drugs was also investigated. Finally, the method was applied for the quality control of commercial gliclazide and repaglinide tablets. Total recovery was 100.40 0.35 and 104.46 0.23% f SD). or gliclazide and repaglinide, respectively [mean SD).
Use of Griess Reagent Containing Vanadium(III) for Post-Column Derivatization and Simultaneous Determination of Nitrite and Nitrate in Baby Food
Authors: Casanova John A , Gross Lois K , McMullen Sarah E , Schenck Frank J
Published: February 2020

An ion chromatographic method with post-column derivatization and spectrophotometric detection is presented for the determination of nitrate and nitrite (NOx) in baby food. NOx residues found naturally or added as preservatives were extracted from baby foods and determined by using ion chromatography with post-column derivatization and spectrophotometric detection. Nitrate was reduced to nitrite online by post-column reduction using vanadium(III) chloride and heat. Nitrite reacted with Griess reagent to produce a dye that was detected at 525 nm. The use of V(III) and heat to promote the reduction of nitrate to nitrite online is a novel feature of this detection system. The determination of incurred NOx residues in samples by using AOAC Method 993.03 yielded results comparable to those obtained by ion chromatography with spectrophotometric detection. The toxic and carcinogenic metal cadmium used in the AOAC Method to reduce the nitrate to nitrite was avoided. The proposed method provides simultaneous determination of nitrate and nitrite. Average recoveries of nitrate and nitrite residues ranged from 82 to 107 for fortification levels of 25400 ppm.
Salmonella Surveillance in AustraliaCreated from Adversity
Authors: Forsyth Jocelyn , Lightfoot Diane , Powling Joan , Tan Agnes
Published: February 2020

A national scheme of Salmonella surveillance emerged in Australia as a direct result of high-profile outbreaks in 1977. A typing laboratory in Victoria put together a working model using the computer technology available at the time. The evolving information-gathering system has stood the test of time and has provided an invaluable bank of information covering isolations from humans and other sources. The databases have been used effectively in detecting trends and outbreaks and have assisted in the solution of public health problemseven extending internationally. The way in which this has been done and the lessons learned are described.
Validation of a Microwell DNA Probe Assay for Detection of Listeria spp. in Foods
Authors: Oyarzabal Omar A , Behnke Nicole M , Mozola Mark A , Andrews Wallace H , Ryser Elliot T , Donnelly Catherine W
Published: February 2020

A new DNA hybridization assay in microwell format for detection of Listeria spp. in foods and environmental samples was developed. This assay uses Listeria-specific oligonucleotide probes labeled with horseradish peroxidase and a photometrically determined end point. Validation studies with 15 different food commodities and a variety of environmental sample types were conducted to compare the performance of this alternative test versus reference methods. Meats, seafood, dairy products, and vegetables comprised the categories of food tested. Food samples were inoculated at 2 levels and refrigerated or frozen for at least 72 h. Uninoculated (negative) control samples were included in each trial. Samples were enriched according to the procedure recommended by either the U.S. Food and Drug Administration (FDA) or the U.S. Department of Agriculture (USDA), Food Safety and Inspection Service (FSIS). Samples enriched for 24 h were transferred to Oxford agar plates and incubated for 24 h. The surface of the plateswas then swabbed and any growth present was transferred to phosphate buffer solution for the performance of the DNA assay. A standard confirmation procedure was used to compare the number of positive samples obtained with the DNA method versus reference methods. Statistical analyses of the results indicate that the proposed alternative method performs equally to cultural referencemethods. TheDNAassay is able to detect as lowas 1 colony-forming unit of Listeria in a 25 g food sample, with results available as early as 48 h after the start of sample enrichment.
Liquid Chromatographic Analysis of Aflatoxin Using Post-Column Photochemical Derivatization: Collaborative Study
Authors: Waltking Arthur E , Wilson David , Dunn E ,   Collaborators:, Chan D , Dunn E , Humphries J , Kandler H , Sizoo E , Wilson D
Published: February 2020

Aflatoxin analysis, with post-column derivatization using a photochemical reactor for enhanced detection (PHRED) system for derivatization, has been compared to the officially recognized iodine and Kobra cell derivatization systems. This photochemical system has been extensively used for screening peanuts by some U.S. Department of Agriculture laboratories for many years. From their periodic method checks, using standard spiked samples, an 80 sample series with each of the 3 derivatization methods was statistically analyzed. Paired comparisons, using the same sample extract, were also made between the PHRED and one of the other 2 methods, among laboratories in 4 different countries, on a variety of naturally contaminated commodity products. The differences between the techniques were not significant for peanuts, but for corn the photochemical system consistently gave slightly higher values for aflatoxins B1 and B2 than the Kobra cell method. However, a comparison of all sample results showed no significant differences between methods. The Pearson correlation coefficients for aflatoxin B1 in 102 test samples and aflatoxin B2 in 94 test samples were 0.9994 and 0.9874, respectively. The probability factor was P < 0.0001, and the t-tests were not significantly different except for the corn. These indicated that the PHRED system is equivalent to the iodine and Kobra cell methods for peanuts relative to the current official procedures, but the PHRED system has a slightly high bias for corn compared to the iodine and Kobra cell systems.
Multiplex-Polymerase Chain Reaction Assay for the Authentication of the Mackerel Scomber colias in Commercial Canned Products
Authors: Infante Carlos , Manchado Manuel
Published: February 2020

A multiplex-polymerase chain reaction (PCR) system was developed for the authentication of the mackerel Scomber colias in commercial canned products. This novel method consists of an S. colias-specific fragment [159 base pairs (bp)] located in the nontranscribed spacer (NTS) sequence, and a Scomber genus-specific PCR product in the 5S rRNA gene (196201 bp) as a positive amplification control. The system was assayed using 18 different canned products labeled as S. colias. A positive identification was made in all but one sample, revealing this methodology as a potential molecular tool for direct application in the authentication of S. colias canned products.
Evaluation of a Preclinical Blood Test for Scrapie in Sheep Using Immunocapillary Electrophoresis
Authors: Jackman Roy , Everest David J , Schmerr Mary Jo , Khawaja Mohammed , Keep Pat , Docherty John
Published: February 2020

An analytical method is described for detection of endogenous disease-associated prion protein in the buffy coat fraction from the blood of sheep infected with scrapie. The method has been improved and evaluated for its performance in the preclinical diagnosis of ovine transmissible spongiform encephalopathies. The test system uses a protocol for sample preparation that includes extraction and concentration and a test method that uses a liquid-phase competitive immunoassay for prion protein. Antibodies directed to a peptide sequence at the C-terminus of the prion protein (PrP) and a fluorescein-labeled peptide conjugate are used in the assay. Free zone capillary electrophoresis with laser-induced fluorescence for detection is used to separate the antibody-bound fluorescently labeled peptide and free labeled peptide. In this assay, the PrP competes with the fluorescently labeled peptide for limited antibody binding sites, which results in a reduction of the peak representing the immunocomplex of the antibody bound to the fluorescently labeled peptide. When blood samples from scrapie-infected sheep aged 712 months and of the scrapie-susceptible PrP genotypes VRQ/VRQ and VRQ/ARQ were analyzed, the abnormal PrP was found in blood samples. These results correlated with the post-mortem diagnosis of scrapie. The sheep were preclinical and appeared normal at the time of testing but later died with clinical disease approximately 12 months after testing. In older animals, and those with clinical signs, a smaller percentage of animals tested positive. This study has demonstrated that this technology can be used as a sensitive, rapid preclinical test to detect the disease-associated PrP in the blood of scrapie-infected sheep. Improvements in the extraction protocol and capillary electrophoresis conditions will enhance the robustness of this test.
Biosensor Screening for Veterinary Drug Residues in Foodstuffs
Authors: Haughey Simon A , Baxter G Andrew
Published: February 2020

The advent of the surface plasmon resonance (SPR) biosensor has led to many applications in diverse fields from the pharmaceutical industry to the life sciences and other areas within biotechnology. One area that has seen a significant increase in applications is the testing for veterinary drug residues in foodstuffs. These include tests for antibiotics, β-agonists, and antiparasitic drugs. The introduction of the BiacorerQ in the late 1990s, an SPR biosensor dedicated to the food industry, and the complementary development of kits to test for these residues mean that end users have a viable alternative screening test to the established enzyme-linked immunosorbent assay (ELISA) techniques. This paper reviews many SPR biosensor veterinary drug tests that have been developed, with particular emphasis placed on kit-based assays.
Sampling Hazelnuts for Aflatoxin: Uncertainty Associated with Sampling, Sample Preparation, and Analysis
Authors: Ozay Guner , Seyhan Ferda , Yilmaz Aysun , Whitaker Thomas B , Slate Andrew B , Giesbrecht Francis
Published: February 2020

The variability associated with the aflatoxin test procedure used to estimate aflatoxin levels in bulk shipments of hazelnuts was investigated. Sixteen 10 kg samples of shelled hazelnuts were taken from each of 20 lots that were suspected of aflatoxin contamination. The total variance associated with testing shelled hazelnuts was estimated and partitioned into sampling, sample preparation, and analytical variance components. Each variance component increased as aflatoxin concentration (either B1 or total) increased. With the use of regression analysis, mathematical expressions were developed to model the relationship between aflatoxin concentration and the total, sampling, sample preparation, and analytical variances. The expressions for these relationships were used to estimate the variance for any sample size, subsample size, and number of analyses for a specific aflatoxin concentration. The sampling, sample preparation, and analytical variances associated with estimating aflatoxin in a hazelnut lot at a total aflatoxin level of 10 ng/g and using a 10 kg sample, a 50 g subsample, dry comminution with a Robot Coupe mill, and a highperformance liquid chromatographic analytical method are 174.40, 0.74, and 0.27, respectively. The sampling, sample preparation, and analytical steps of the aflatoxin test procedure accounted for 99.4, 0.4, and 0.2% of the total variability, respectively.
Liquid Chromatographic Determination of Deoxynivalenol in Baby Food and Animal Feed: Interlaboratory Study
Authors: Stroka Joerg , Derbyshire Michelle , Mischke Carsten , Ambrosio Massimo , Kroeger Katy , Arranz Isabel , Sizoo Eric , van Egmond Hans ,   Collaborators:, De Girolama A , Herry M-P , Kereszturi J , Klaffke H , Koch P , Krska R , Lauber U , Petrová J , Petterson H , Reif K , Reutter M , Sunderland J , Sundin P , Vögler P
Published: February 2020

An interlaboratory study was conducted for the determination of deoxynivalenol in baby food and animal feed by high-performance liquid chromatography with UV detection. The study included 14 participants representing a cross section of industry, official food control, and research facilities. Mean recoveries reported ranged from 89% (at 120 g/kg) to 85% (at 240 g/kg) for baby food and from 100% (at 200 g/kg) to 93% (at 400 g/kg) for animal feed. On the basis of the results for spiked samples (blind duplicates at 2 levels), as well as those for naturally contaminated samples (blind duplicates at 3 levels), the relative standard deviation for repeatability (RSDr) in analyses of baby food ranged from 6.4 to 14.0% and in analyses of animal feed, from 6.1 to 16.5%. The relative standard deviation for reproducibility (RSDR) in analyses of baby food ranged from 9.4 to 19.5% and in analyses of animal feed, from 10.5 to 25.2%. The HorRat values ranged from 0.4 to 1.0 and from 0.7 to 1.3, for baby food and animal feed, respectively. The method showed acceptable performance for within-laboratory and between-laboratory precision for each matrix, as required by European legislation.
Sampling Almonds for Aflatoxin, Part I: Estimation of Uncertainty Associated with Sampling, Sample Preparation, and Analysis
Authors: Whitaker Thomas B , Slate Andrew B , Jacobs Merle , Hurley J Michael , Adams Julie G , Giesbrecht Francis G
Published: February 2020

Domestic and international regulatory limits have been established for aflatoxin in almonds and other tree nuts. It is difficult to obtain an accurate and precise estimate of the true aflatoxin concentration in a bulk lot because of the uncertainty associated with the sampling, sample preparation, and analytical steps of the aflatoxin test procedure. To evaluate the performance of aflatoxin sampling plans, the uncertainty associated with sampling lots of shelled almonds for aflatoxin was investigated. Twenty lots of shelled almonds were sampled for aflatoxin contamination. The total variance associated with measuring B1 and total aflatoxins in bulk almond lots was estimated and partitioned into sampling, sample preparation, and analytical variance components. All variances were found to increase with an increase in aflatoxin concentration (both B1 and total). By using regression analysis, mathematical expressions were developed to predict the relationship between each variance component (total, sampling, sample preparation, and analysis variances) and aflatoxin concentration. Variance estimates were the same for B1 and total aflatoxins. The mathematical relationships can be used to estimate each variance for a given sample size, subsample size, and number of analyses other than that measured in the study. When a lot with total aflatoxins at 15 ng/g was tested by using a 10 kg sample, a vertical cutter mixer type of mill, a 100 g subsample, and high-performance liquid chromatography analysis, the sampling, sample preparation, analytical, and total variances (coefficient of variation, CV) were 394.7 (CV, 132.4%), 14.7 (CV, 25.5%), 0.8 (CV, 6.1%), and 410.2 (CV, 135.0%), respectively. The percentages of the total variance associated with sampling, sample preparation, and analytical steps were 96.2, 3.6, and 0.2, respectively.
Evaluation of a Chemiluminescence Method for Measuring Alkaline Phosphatase Activity in WholeMilk of Multiple Species and Bovine Dairy Drinks: Interlaboratory Study
Authors: Salter Robert S , Fitchen John ,   Collaborators:, Bain B , Bella M , Bergman S , Biotelle A C , Bulthaus M , Butterworth F , Collins P , Davag R , Farrington D , Gaunt W , Greenwood M , Hickey B , High E , Irvine F , Lupi L , Martin G , Maturin L , Mode G , Nicholas M , O'Grady F , Pearce L , Reddy R , Robertson R , Schwartz J , Shelley S
Published: February 2020

Alkaline phosphatase (ALP) is a ubiquitous enzyme in milk with timetemperature destruction similar to that of certain pathogens destroyed in pasteurization. Measurement of ALP to indicate proper pasteurization is a common practice. Recently the public health level for ALP was decreased to 350 mU/L, a level below the sensitivity of older colorimetric ALP methods. This study was conducted within the structure of the International Dairy Federation and the International Organization for Standardization to evaluate the reproducibility of the chemiluminescence method (Charm PasLite) for ALP at 50, 100, 350, and 500 mU/L in whole milk of multiple species to meet new regulations in the United States and proposed regulations in the European Union (EU). Fifteen laboratories from 8 countries evaluated bovine, goat, sheep, and buffalo milk, bovine skim milk, 20% fat cream, and 2% fat chocolate milk. At ALP levels of 350 and 500 mU/L, the average relative standard deviation for repeatability (RSDr) was 7.5%, and the average relative standard deviation of reproducibility was (RSDR) 15%. For ALP at 100 and 50 mU/L, the average RSDr values were 10.5 and 12.6%, respectively, and the average RSDR values were 18 and 25%, respectively. The limit of detection was 20 mU/L. Results are comparable to those obtained with other enzymatic photo-activated system methods such as the fluorometric method. Results indicate that the method is suitable for measuring ALP in the milk of multiple species and in dairy drinks at U.S. and proposed EU levels.
Multiresidue Analysis of Avermectins in Cattle Liver by Liquid Chromatography/Tandem Mass Spectrometry
Authors: Hou Xiaolin , Jiang Haiyang , Ding Shuangyang , Zhang Suxia , Li Xiaowei , Shen Jianzhong
Published: February 2020

A simple multiresidue analysis method was developed for the confirmation and quantification of eprinomectin, abamectin, doramectin, and ivermectin in cattle liver. The target analytes were extracted with acetonitrile and cleaned up with C18 and C8 solid-phase extraction cartridges before analysis by liquid chromatography combined with positive ion electrospray tandem mass spectrometry. The residue mean recoveries of the 4 drugs were 64.1699.53%. The limit of detection was 2.5 ng/g for eprinomectin, abamectin, doramectin, and ivermectin.
An Accurate and Reproducible Method for the Quantitative Analysis of Isoflavones and Their Metabolites in Rat Plasma Using Liquid Chromatography/Mass Spectrometry Combined with Photodiode Array Detection
Authors: Sepehr Estatira , Robertson Patrick , Gilani G Sarwar , Cooke Gerard , Pui-Yan Lau Benjamin
Published: February 2020

To study the safety and potential health benefits of soy isoflavones, a rapid and simple method based on liquid chromatography combined with mass spectrometry (LC/MS) and photodiode array detector (PDA) was developed for the determination of isoflavones in rat plasma. The analytes included daidzein, genistein, glycitein, equol, 4-ethyl phenol, and biochanin A over a concentration range of 1.04320.0 nM using 75 L of rat plasma. Rat plasma samples were hydrolyzed by adding an enzyme mixture from Helix pomatia containing glucuronidase and sulfatase to convert the isoflavone -glycosides daidzin, genistin, and glycitin to their active aglycone forms. A liquidliquid extraction method using ethyl acetate as the extraction solvent was used to extract aglycones and the internal standards (phenolphthalein -d glucuronide, 4-methylumbelliferyl sulfate, and apigenin) from digested plasma samples. The extract was evaporated to dryness under a nitrogen stream, reconstituted with 0.1%formic acid in wateracetonitrile (85 + 15), and injected into a Zorbax SB-CN reversed-phase column (4.6 75 mm, 3.5 m particle size). The Micromass ZQ detector was operated in the positive ion selected-ion monitoring mode. The flow rate for LC was 1.0 mL/ min, with a split where 25% of the effluent was introduced into the electrospray ionization probe of the MS instrument and 75% into the PDA. The chromatographic run time was 16.0 min, with delay of 10 min/injection. The interday precision and accuracy of the standard samples were <2.6% relative standard deviation and <10% relative error, respectively. Recovery of the reported isoflavones with this method varied from 86 to 100%.
Liquid Chromatographic Determination of Maleic Hydrazide in Technical and Formulated Products: Collaborative Study
Authors: Mertz James L , Lau Dora Y , Borth David M ,   Collaborators:, Ausan E D , Bennett O , Bontoyan W , Colvin T , Curry M , Firman M , Golden P , Goodwin V , Krol W , Kosse M , Lacroix M , Mattina M , Phillips T , Podhorniak L , Porticos L , Qian Y , Rose J , Schermerhorn P , Weiss C
Published: February 2020

Fourteen collaborating laboratories assayed maleic hydrazide (MH), 6-hydroxypyridazin-3(2H)-one, in technical and formulated products by reversed-phase liquid chromatography (LC) with sulfanilic acid as an internal standard. The active MH in the samples (6 lots) ranged from 16% (expressed as the potassium salt) to 98% (MH in the technical). A small amount of 1 M KOH was added to the technical MH and analytical standards to create the potassium salt of the analyte which is soluble in water. Test samples and standards were extracted with water containing the internal standard before analysis by LC on a C8 column with an ion-pairing eluting solution and UV detection at 254 nm. The concentration of MH was calculated by comparing the peak area response ratios of the analyte and the internal standard with those in the analytical standard solution. Eleven laboratories weighed each test sample twice with single analysis. Three laboratories weighed each sample once and made duplicate injections on the LC system. The data were analyzed using the 11 laboratories' results. A second data analysis was done including all laboratory results using a Youden pair approach, selecting one of 2 duplicate assay values randomly for each laboratory and sample. In the first data analysis, the repeatability standard deviation ranged from 0.07 to 1.39%; reproducibility standard deviation ranged from 0.22 to 1.39%. In the second data analysis (using all laboratory data), repeatability standard deviation ranged from 0.09 to 0.86%; reproducibility standard deviation ranged from 0.22 to 1.31%.
Affinity Liquid Chromatography Method for the Quantification of Immunoglobulin G in Bovine Colostrum Powders
Authors: Copestake David E J , Indyk Harvey E , Otter Don E
Published: February 2020

An affinity liquid chromatography (LC) method for the determination of bovine immunoglobulin G (IgG), using protein G coupled to an agarose support, was modified to permit the quantification of IgG in colostrum-based powders. Sample preparation included pH adjustment to 4.6 to precipitate casein and denatured whey protein. The method was applied to a range of colostrum powders and was compared with the alternative independent methods of surface plasmon resonance immunoassay, radial immunodiffusion, and reversed-phase LC. The method was rapid, and performance parameters included a working range of 10-150 μg IgG and precision relative standard deviation values of <10%.
Detection of Bovine Meat and Bone Meal in Animal Feed at a Level of 0.1%
Authors: Aarts Henk J M , Bouw El M , Buntjer Jaap B , Lenstra Johannes A , Raamsdonk Leo W D  van
Published: February 2020

For the control of the transmission of bovine spongiform encephalopathy in cattle via feedstuff, a real-time polymerase chain reaction assay was developed with ruminant-specific Bov-B SINE primers, SYBR® Green fluorescence detection, and melting curve analysis. In formulated cattle and chicken feed samples spiked with pure bovine and sheep meat and bone meal heated at 133C for 20 min, a contamination level of 0.1% was detected.
Spectrofluorometric Determination of Verapamil Hydrochloride in Pharmaceutical Preparations and Human Plasma Using Organized Media: Application to Stability Studies
Authors: Walash Mohamed , Belal Fathalla , El-Enany Nahed , Abdelsalam Amina
Published: February 2020

A highly sensitive spectrofluorometric method was developed for the determination of verapamil hydrochloride (VP HCl) in pharmaceutical formulations and biological fluids. The proposed method is based on investigation of the fluorescence spectral behavior of VP HCl in micellar systems, such as sodium dodecyl sulfate (SDS) and β-cyclodextrin (β-CD). In aqueous solutions of borate buffer of pH 9 and 8.5, VP HCl was well incorporated into SDS and β-CD, respectively, with enhancement of its native fluorescence. The fluorescence was measured at 318 nm after excitation at 231 nm. The fluorescence intensity enhancements were 183 and 107% in SDS and in β-CD, respectively. The fluorescence-concentration plots were rectilinear over the range of 0.020.2 and 0.020.25 μg/mL, with lower detection limits of 5.58 × 103 and 3.62 × 103 μg/mL in SDS and β-CD, respectively. The method was successfully applied to the analysis of commercial tablets and the results were in good agreement with those obtained with the official method. The method was further applied to the determination of VP HCl in real and spiked human plasma. The mean % recoveries in the case of spiked human plasma (n 4) was 92.59 3.11 and 88.35 2.55 using SDS and β-CD, respectively, while that in real human plasma (n 3) was 90.17 6.93 and 89.17 6.50 using SDS and β-CD, respectively. The application of the method was extended to the stability studies of VP HCl after exposureto ultraviolet radiation and upon oxidation with hydrogen peroxide.
Method Modification (2004.08) to Field Testing of Visible Powders on a Variety of Nonporous Environmental Surfaces: Field Study
Authors: Harper Bruce , Robinson Matthew ,   Collaborators:, Agle N , Badar T , Bartle D , Decker A , Gailey J , Hall M , Hoffman G , Jennings B , Johnson L , Jorgensen C , Lesson A , Marsh B , McLean J , Merrill K , Piland M , Salitros N , Trigg M
Published: February 2020

The RAMP® Anthrax Test Cartridge for detecting Bacillus anthracis was validated for use in the field for detection of B. anthracis spores in visible powder residues on 7 nonporous environmental surfaces. Six teams of trained first responders and civil support personnel in Class C personal protective equipment sampled visible powder residues on plastic, stainless steel, ceramic tile, wood, rubber, sealed concrete, and food-grade painted wood and analyzed the samples on the RAMP Anthrax Test System. The accuracy for each surface was at least 97% and the overall average was 98.8%. The overall average false-positive rate was 1.79% and false-negative rate was 1.07% for all surfaces. There were no significant differences between surfaces or between spore levels.
Multiresidue Determination of Zeranol and Related Compounds in Bovine Muscle by Gas Chromatography/Mass Spectrometry with Immunoaffinity Cleanup
Authors: Zhang Wei , Wang Hejia , Wang Jianping , Li Xiaowei , Jiang Haiyang , Shen Jianzhong
Published: February 2020

A gas chromatography/mass spectrometry (GC/MS) method with immunoaffinity cleanup was developed for the determination of zeranol and related compounds, taleranol, zearalanone, and α-zearalenol in bovine muscle. Muscle samples were extracted with methanol and cleaned up with immunoaffinity chromatography (IAC) columns containing monoclonal antibodies raised against zeranol coupled to CNBr-activated Sepharose 4B. After derivatization, the compounds were analyzed by GC/MS. The dynamic column capacities for zeranol, taleranol, zearalanone, and α-zearalenol were 2639.7, 2840.3, 2731.5, and 2736.3 ng/mL Sepharose gel, respectively. The limits of detection and quantification were 0.5 and 1.0 ng/g, respectively, for all 4 compounds. Mean recoveries were 79.6110.7% with coefficients of variation of 3.211.4% at spiked levels of 1.05.0 ng/g. This IAC-GC/MS method may be used for the determination of zeranol, taleranol, zearalanone, and α-zearalenol residues in bovine muscle, and possibly other tissues.
Analysis of Mitochondrial DNA for Authentication of Meats from Chamois (Rupicapra rupicapra), Pyrenean Ibex (Capra pyrenaica), and Mouflon (Ovis ammon) by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism
Authors: Fajardo Violeta , González Isabel , López-Calleja Inés , Martín Irene , Rojas María , Pavón Miguel Ángel , Hernández Pablo E , García Teresa , Martín Rosario
Published: February 2020

The prevention of fraudulent labeling of game meat constitutes an important part of food regulatory control and quality assurance systems. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis based on mitochondrial deoxyribonucleic acid (DNA) was developed for authentication of meats from chamois (Rupicapra rupicapra), pyrenean ibex (Capra pyrenaica), and mouflon (Ovis ammon). Amplification and restriction site analysis of a DNA fragment about 720 base pairs (bp) from the mitochondrial 12S rRNA gene of all analyzed species permitted the selection of MseI and ApoI endonucleases for meat speciation. The 12S rRNA restriction profiles obtained allowed the unequivocal identification of chamois, pyrenean ibex, and mouflon/sheep and their differentiation from meats of domestic species such as cattle, goat, and swine. The highly variable mitochondrial D-loop gene was also targeted to attempt discrimination between mouflon and sheep meats. A D-loop region (700-1000 bp) was amplified and sequenced in all game and domestic species analyzed, and a primer set was designed for the selective amplification of a 370 bp DNA fragment from mouflon and sheep. PCR-RFLP analysis with the selected MaeII enzyme generated a single electrophoretic profile characteristic for sheep, whereas 3 different fragment patterns were obtained for mouflon meats. Consequently, the PCR-RFLP technique developed can be routinely applied in inspection programs in order to verify the correct labeling of game species.
A Simplified Modification of the AOAC Official Method for Determination of Total Dietary Fiber Using Newly Developed Enzymes: Preliminary Interlaboratory Study
Authors: Kanaya Kenichiro , Tada Shusaku , Mori Bunpei , Takahashi Rie , Ikegami Sachie , Kurasawa Shin’ichi , Okuzaki Masami , Mori Yoko , Innami Satoshi ,   Collaborators:, Hori H , Negishi Y , Nunobiki M , Onuki J , Umeki M , Yoshii N
Published: February 2020

A preliminary interlaboratory study was conducted to evaluate the validity of the modified AOAC method for determination of total dietary fiber by Tada and Innami, in which the 3-step enzymatic digestion process in AOAC Method 991.43 is modified to a 2-step process without pH adjustment. Total dietary fiber contents in 8 representative foodstuffs were measured using both the original AOAC Method 991.43 and the modified method in 6 research facilities in Japan. Repeatability relative standard deviations, reproducibility relative standard deviations, and Horwitz ratio values from the modified method were equivalent to those from AOAC Method 991.43, except in the rice sample. However, this exceptional case shown in the modified method was entirely dissolved by the addition of α-amylase stabilizing agents. The modified method, which shortens the process of enzymatic digestion from 3 to 2 steps and in which only reaction temperature is adjusted under the same pH, was found not only to give accurate values comparable to the original method, but also to substantially reduce the labor required by the laboratory staff in the process of routine analysis. This study revealed that the validity of the modified method was further ensured by adding α-amylase stabilizing agents to the reaction system.
Determination of the Anthraquinones Aloe-Emodin and Aloin-A by Liquid Chromatography with Mass Spectrometric and Diode Array Detection
Authors: Elsohly Mahmoud A , Gul Waseem , Avula Bharathi , Khan Ikhlas A
Published: February 2020

Methods using liquid chromatography/mass spectrometry (LC/MS) and LC with diode array detection (DAD) in the UV range (LC/UV) were developed for the determination of low levels of the anthraquinones aloe-emodin and aloin-A (barbaloin) in aloe-based products. The methods were used to analyze several commercial products (liquids, semisolids, and solids) for the 2 anthraquinones. The wavelengths used for quantification of aloin-A, aloe-emodin, and emodin (internal standard) by DAD were 357, 257, and 289 nm, respectively. The on-column sensitivities were 0.25 and 0.05 ng by LC/UV and 0.01 and 0.025 ng by LC/MS for aloin-A and aloe-emodin, respectively. The methods are simple and sensitive and provide reproducible results; therefore, they are suitable for the determination of these anthraquinones in various aloe-based products.
Standard Practice for Bulk Sample Collection and Swab Sample Collection of Visible Powders Suspected of Being Biological Agents from Nonporous Surfaces: Collaborative Study
Authors: Locascio Laurie E , Harper Bruce , Robinson Matthew , Badar T
Published: February 2020

The draft ASTM Standard, Standard Practice for Bulk Sample Collection and Swab Sample Collection of Visible Powders Suspected of Being Biological Agents from Nonporous Surfaces,’’ was validated in a collaborative study consisting of 6 teams comprised of Civil Support personnel and First Responders, 2 levels of Bacillus anthracis Sterne and Bacillus thuringiensis Kurstaki spores, and 7 nonporous surfaces. The sample collection standard includes collection of the bulk sample (Method A) using a dry swab to push the sample onto a collection card and collection of residual sample (Method B) using an onsite test kit followed by a wet swab intended for additional onsite testing. Method A is to be performed prior to Method B in order to preserve unadulterated sample as potential criminal evidence. While statistical differences were observed between surfaces, between teams, and the interaction of surfaces and teams for the various sample types collected, these differences are due to the very low variability of the data and a much more narrow distribution than an ideal normal distribution, rather than to any practical differences. The data demonstrate that from both the 1.0 and 0.01 g powder samples, high levels of spores (mean >106 CFU) are recovered from the 7 surfaces by both the dry swab used in bulk sample collection (Method A) and the wet swab (Method B) sampling of the residual powder after bulk sample collection. Thus, after bulk sample collection, there is a high level of residual spores remaining for onsite biological testing and both Methods A and B should be performed in the field.