bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating the Performance of Sampling Plans to Detect Hypoglycin A in Ackee Fruit Shipments Imported into the United States
Authors: Whitaker Thomas B , Saltsman Joyce J , Ware George M , Slate Andrew B
Published: February 2020

Hypoglycin A (HGA) is a toxic amino acid that is naturally produced in unripe ackee fruit. In 1973, the U.S. Food and Drug Administration (FDA) placed a worldwide import alert on ackee fruit, which banned the product from entering the United States. The FDA has considered establishing a regulatory limit for HGA and lifting the ban, which will require development of a monitoring program. The establishment of a regulatory limit for HGA requires the development of a scientifically based sampling plan to detect HGA in ackee fruit imported into the United States. Thirty-three lots of ackee fruit were sampled according to an experimental protocol in which 10 samples, i.e., ten 19 oz cans, were randomly taken from each lot and analyzed for HGA by using liquid chromatography. The total variance was partitioned into sampling and analytical variance components, which were found to be a function of the HGA concentration. Regression equations were developed to predict the total, sampling, and analytical variances as a function of HGA concentration. The observed HGA distribution among the test results for the 10 HGA samples was compared with the normal and lognormal distributions. A computer model based on the lognormal distribution was developed to predict the performance of sampling plan designs to detect HGA in ackee fruit shipments. The performance of several sampling plan designs was evaluated to demonstrate how to manipulate sample size and accept/reject limits to reduce misclassification of ackee fruit lots.
Determination of the Cross-Reactivities for -Zearalenol, -Zearalenol, Zearalanone, -Zearalanol, and -Zearalanol on Three Commercial Immunoaffinity Columns Targeting Zearalenone
Authors: Erbs Marianne , Hartmann Nccolo , Bucheli Thomas D
Published: February 2020

Immunoaffinity extraction has become increasingly important as a sample preparation and cleanup method in mycotoxin analysis. In this study, the antibody specificities of 3 commercial immunoaffinity columns (IACs) targeting zearalenone (ZON) were compared for -zearalenol, -zearalenol, zearalanone, -zearalanol, and -zearalanol. The recoveries of ZON and its 5 analogs were determined in triplicate when extracted from 10 mL circumneutral river water samples spiked with 20 ng analyte individually or in a mixture. The analytes were analyzed by means of electrospray ionization liquid chromatography/tandem mass spectrometry using deuterated internal standards for quantitation. Recoveries ranged from 69 to 115% for all analytes with relative standard deviations of 139%. Cross-reactivities for the analogs were >80% when applied both individually and in a mixture. No significant competition effects were observed when the compounds were applied as a multianalyte mixture well below the stated IAC capacities. The results obtained here demonstrate that all IACs tested are highly cross-reactive towards the 5 ZON derivatives and may be applied for their simultaneous extraction or cleanup.
Validation of RAPID'E. coli 2 for Enumeration and Differentiation of Escherichia coli and Other Coliform Bacteria in Selected FoodsPerformance-Tested MethodSM 050601
Authors: Lauer Wendy F , Martinez Frederic L , Patel Asmita
Published: February 2020

RAPID'E. coli 2 agar (Bio-Rad Laboratories, Hercules, CA) is a chromogenic medium for differentiation and enumeration of E. coli and non-E. coli coliform bacteria in food. The principle of RAPID'E. coli 2 medium relies on simultaneous detection of 2 enzymatic activities, -d-glucuronidase (GLUC) and -d-galactosidase (GAL). Coliforms, other than E. coli (GAL+/GLUC), form blue to green colonies, whereas, specifically, E. coli (GAL+/GLUC+) form violet colonies. Eleven foods (raw ground beef, raw boneless pork, fermented sausage, processed ham, processed turkey, frozen turkey breast, raw ground chicken, cottage cheese, ricotta cheese, raw milk, and dry infant formula) were validated, comparing the performance of RAPID'E. coli 2 agar to the reference method AOAC 966.24. Two sample incubation temperatures were evaluated, 37 and 44C, testing a mixture of naturally and artificially contaminated foods. If naturally contaminated food was not available, thematrix was artificially inoculated with one E. coli strain and one non-E. coli coliform strain. Method comparison studies demonstrated some statistical differences between the 2 methods, which are expected when a plating method is compared to a most probable number method. Inclusivity and exclusivity rates of the medium were 99 and 94, respectively. The RAPID'E. coli 2 method was shown to be stable when minor variations were introduced.
Direct Method for Determination of Sudan I in FD&C Yellow No. 6 and D&C Orange No. 4 by Reversed-Phase Liquid Chromatography
Authors: Petigara Bhakti R , Scher Alan L
Published: February 2020

A reversed-phase liquid chromatographic method was developed to determine parts-per-million and higher levels of Sudan I, 1-(phenylazo)-2-naphthalenol, in the disulfo monoazo color additive FD&C Yellow No. 6 and in a related monosulfo monoazo color additive, D&C Orange No. 4. Sudan I, the corresponding unsulfonated monoazo dye, is a known impurity in these color additives. The color additives are dissolved in water and methanol, and the filtered solutions are directly chromatographed, without extraction or concentration, by using gradient elution at 0.25 mL/min. Calibrations from peak areas at 485 nm were linear. At a 99 confidence level, the limits of determination were 0.008 g Sudan I/mL (0.4 ppm) in FD&C Yellow No. 6 and 0.011 g Sudan I/mL (0.00011) in D&C Orange No. 4. The confidence intervals were 0.202 0.002 g Sudan I/mL (10.1 0.1 ppm) near the specification level for Sudan I in FD&C Yellow No. 6 and 20.0 0.2 g Sudan I/mL (0.200 0.002) near the highest concentration of Sudan I found in D&C Orange No. 4. A survey was conducted to determine Sudan I in 28 samples of FD&C Yellow No. 6 from 17 international manufacturers over 3 years, and in a pharmacology-tested sample. These samples were found to contain undetected levels (16 samples), 0.59.7 ppm Sudan I (0.010.194 g Sudan I/mL in analyzed solutions; 11 samples including the pharmacology sample), and 10 ppm Sudan I (0.2 g Sudan I/mL; 2 samples). Analyses of 21 samples of D&C Orange No. 4 from 8 international manufacturers over 4 years found Sudan I at undetected levels (8 samples), 0.0005 to <0.005 Sudan I (0.05 to <0.5 g Sudan I/mL in analyzed solutions; 3 samples, including a pharmacology batch), 0.005 to <0.05 Sudan I (0.5 to <5 g Sudan I/mL; 9 samples), and 0.18 Sudan I (18 g Sudan I/mL; 1 sample).
Validation of a Dissociation Enhanced Lanthanide Fluorescence Immunoassay for the Screening of 17 -Estradiol in Bovine Serum According to European Union Decision 2002/657/EC
Authors: Scalas Daniela , Squadrone Stefania , Gili Marilena , Marchis Daniela , Prearo Marino , Abete Maria Cesarina
Published: February 2020

A validation study was carried out in order to evaluate the performances of a dissociation enhanced lanthanide fluorescence immunoassay (DELFIA) for rapid screening of 17 -Estradiol in bovine serum. This validation was performed according to European Union (EU) Decision 2002/657/EC, which establishes criteria and procedures for determination of detection capability (CC), selectivity/specificity, and applicability/ruggedness/stability for qualitative screening tests. To determine these performance characteristics, 20 blank serum samples of cattle were collected and spiked with 17 -Estradiol at 40 pg/mL, corresponding to the maximum residue limit permitted by Italian legislation. According to the EU Decision CC criterion, spiked samples must have <5 probability to be classified as a false negative. 17 -Estradiol was detected in each spiked sample, and the CC results were <40 pg/mL. There was also no observed interference effect due to chemically related substances or from the matrix. Moreover, slight variations of some critical factors in the DELFIA procedure, deliberately introduced for ruggedness evaluation, did not result in any negative effect on the 17 -Estradiol detection. The proposed method is suitable for qualitative screening analysis of 17 -Estradiol according to EU performance requirements.
Utilizing Biotechnology in Producing Fats and Oils with Various Nutritional Properties
Authors: Flickinger Brent D
Published: February 2020

The role of dietary fat in health and wellness continues to evolve. In today's environment, trans fatty acids and obesity are issues that are impacted by dietary fat. In response to new information in these areas, changes in the amount and composition of edible fats and oils have occurred and are occurring. These compositional changes include variation in fatty acid composition and innovation in fat structure. Soybean, canola, and sunflower are examples of oilseeds with varied fatty acid composition, including mid-oleic, high-oleic, and low-linolenic traits. These trait-enhanced oils are aimed to displace partially hydrogenated vegetable oils primarily in frying applications. Examples of oils with innovation in fat structure include enzyme interesterified (EIE) fats and oils and diacylglycerol oil. EIE fats are a commercial edible fat innovation, where a lipase is used to modify the fat structure of a blend of hard fat and liquid oil. EIE fats are aimed to displace partially hydrogenated vegetable oils in baking and spread applications. Diacylglycerol and medium-chain triglyceride (MCT)-based oils are commercial edible oil innovations. Diacylglycerol and MCT-based oils are aimed for individuals looking to store less of these fats as body fat when they are used in place of traditional cooking and salad oils.
Detection and Characterization of cry1Ac Transgene Construct in Bt Cotton: Multiple Polymerase Chain Reaction Approach
Authors: Singh Chandra K , Ojha Abhishek , Kachru Devendra N
Published: February 2020

To comply with international labeling regulations for genetically modified (GM) crops and food, and to enable proper identification of GM organisms (GMOs), effective methodologies and reliable approaches are needed. The spurious and unapproved GM planting has contributed to crop failures and commercial losses. To ensure effective and genuine GM cultivation, a methodology is needed to detect and identify the trait of interest and concurrently evaluate the structural and functional stability of the transgene insert. A multiple polymerase chain reaction (PCR) approach was developed for detection, identification, and gene stability confirmation of cry1Ac transgene construct in Bt cotton. As many as 9 samples of Bt cotton hybrid seeds comprising 3 approved Bt hybrids, MECH-12Bt, MECH-162Bt, MECH-184Bt, and a batch of 6 nonapproved Bt hybrids were tested. Initially, single standard PCR assays were run to amplify predominant GM DNA sequences (CaMV 35S promoter, nos terminator, and npt-II marker gene); a housekeeping gene, Gossypium hirsutum fiber-specific acyl carrier protein gene (acp1); a trait-specific transgene (cry1Ac); and a sequence of 7S 3 transcription terminator which specifically borders with 3 region of cry1Ac transgene cassette. The concurrent amplification of all sequences of the entire cassette was performed by 3 assays, duplex, triplex, and quadruplex multiplex PCR assays, under common assay conditions. The identity of amplicons was reconfirmed by restriction endonuclease digestion profile. The 2 distinct transgene cassettes, cry1Ac and npt-II, of the Bt cotton were amplified using the respective forward primer of promoter and reverse primer of terminator. The resultant amplicons were excised, eluted, and purified. The purified amplicons served as template for nested PCR assays. The nested PCR runs confirmed the transgene construct orientation and identity. The limit of detection as established by our assay for GM trait (cry1Ac) was 0.1. This approach can be adopted as a standard procedure for complete molecular characterization of Bt cotton. These assays will be of interest and use to importers, breeders, research laboratories, safety regulators, and food processors for detection of cry1Ac bearing GMOs.
Influence of Different Extraction Parameters on a Solid-Phase Dynamic Extraction for the Gas Chromatographic Determination of d-Limonene Degradation Products by Using a Fractional Factorial Design
Authors: Kamphoff Marion , Thiele Tobias , Kunz Benno
Published: February 2020

Through the application of a solid-phase dynamic extraction (SPDE) method for the determination of volatile substances, different parameters may influence the extraction and desorption process and are, therefore, vital for the determination of the extracted substances via gas chromatography (GC). In this study, the influence of extraction und desorption parameters of an SPDE-GC method for the determination of the d-limonene degradation products, namely, -terpineol, (-)-carveol, and (S)-carvone, in an aqueous model system was evaluated using a factorial fractional design. The aim was to reduce the number of factors that should be considered for the optimization of an SPDE procedure for different applications. It could be shown that the extraction efficiency of -terpineol, (-)-carveol, and (S)-carvone is significantly influenced by the extraction parameters incubation temperature, number of extraction strokes, and amount of added NaCl. All 3 parameters have a positive effect on the extraction and determination of the examined d-limonene degradation products. Due to the identification of significant factors on the basis of an experimental design, the results of this study can be very useful for further development of SPDE methods for different applications.
Original Normal-Phase High-Performance Liquid Chromatographic Separation of Monoacylglycerol Classes from Extra Virgin Olive Oil Triacylglycerols for Their Stereospecific Analysis
Authors: Petrosino Teresa , Riccieri Roberto , Blasi Francesca , Brutti Monia , D’Arco Gilda , Bosi Ancilla , Maurelli Silvia , Cossignani Lina , Simonetti Maria Stella , Damiani Pietro
Published: February 2020

An innovative procedure to separate the 3 isomeric sn-monoacylglycerols (MAG) classes (sn-1-, sn-2-, sn-3-MAG) is described. MAGs, obtained by chemical deacylation of triacylglycerols (TAGs), have been derivatized with (S)-(+)-1-(1-naphtyl)- ethyl-isocyanate, and the resulting urethane derivatives have been separated by normal-phase high-performance liquid chromatography. This procedure allows resolution as diasteroisomers of the 2 enantiomeric classes (sn-1-MAG and sn-3-MAG), without the need of a chiral column, and to separate also the isomeric sn-2-MAG class; moreover, by introducing a chromophoric moiety, this reagent makes possible the ultraviolet detection of the analyte molecules. This procedure has been used to obtain the stereospecific analysis of the TAG fraction of extra virgin olive oil samples. The use of a nondestructive detector permitted the collection of the individual urethane classes; the fatty acid composition of each was determined by high-resolution gas chromatography, obtaining directly from the data the fatty acid distribution within each sn- position of TAGs. To validate this new method, the results have been compared with those obtained by 2 other procedures for TAG stereospecific analysis, and the obtained results were satisfactory since the proposed method gave data very similar to the other procedures.
Comparison of Hexane and Petroleum Ether to Measure Surface Oil Content
Authors: Buck Vinodini E , Barringer Sheryl A
Published: February 2020

Many studies have measured surface oil on potato chips and spray dried powders using either petroleum ether or hexane. This study compared the effectiveness of the 2 solvents using aluminum squares to ensure oil stays on the surface of the sample during the measurement. Aluminum squares were sprayed with soybean oil, and surface oil was measured immediately and after 1 day. Each of the 8 aluminum samples were individually dipped for 12 s in either hexane or petroleum ether. For immediately extracted samples, there was no significant difference in the amount of oil extracted using either hexane or petroleum ether. For 1-day-old samples, hexane extracted more oil than petroleum ether. Neither method extracted all of the surface oil.
Validation Study to Demonstrate the Equivalence of a Minor Modification of Assurance Enzyme Immunoassay Method, Official Method 996.14, for Detection of Listeria in Foods and Environmental Surfaces to the Reference Culture Methods
Authors: Feldsine Philip T , Kerr David E , Lienau Andrew H
Published: February 2020

The Assurance Enzyme Immunoassay (EIA) for the Detection of Listeria in Foods and Environmental Surfaces, AOAC Official Method 996.14, has been modified to combine the separate antibody and conjugate addition steps into one. A methods comparison study was conducted to demonstrate the equivalence of this modification to the reference culture methods. Two food matrixes and one environmental surface were analyzed. In total, there were valid results from 145 samples and controls. Results showed that the Assurance EIA for Listeria spp. is equivalent to the reference culture methods for the detection of Listeria.
Evaluation of the VIDAS Staph Enterotoxin II (SET 2) Immunoassay Method for the Detection of Staphylococcal Enterotoxins in Selected Foods: Collaborative Study
Authors: Jechorek Robert P , Johnson Ronald L ,   Collaborators:, Agin J , Anderson G , Bennett R , Brown M , Dammann H , DuCloux W , Elems C , Hawryluk T , Hernandez C , Johnson L A , Koschmann C , Lugovaz I , Moon B , Moore S , Porter M , Purvis U , Riva J , Shaw C , Wessinger A
Published: February 2020

A multilaboratory study was conducted to determine the limit of detection (LOD) of Staphylococcal enterotoxins (SET) in 5 foods. Cooked chicken, ham, potato salad, pasteurized liquid whole milk, and canned mushrooms were each spiked with a different enterotoxin (A, B, C1, D, or E), and tested at 0.25 and 0.5 ng/g SET levels to determine the LOD of the assay for those foods in a collaborative study. Unspiked controls were also included. A total of 19 laboratories representing government and industry participated. In this study, 1674 test portions were analyzed, of which 1638 were used in the statistical analysis. Of the 1638 test portions used in the statistical analysis, 1104 were spiked test portions, of which 1073 were positive by the VIDAS Staph enterotoxin II (SET 2) method. The detection rates at the 0.25 ng/mL level were cooked chicken, 98.2; ham, 99.0; potato salad, 99.1; liquid whole milk, 85.2; and canned mushrooms, 100. The detection rates at the 0.5 ng/mL level were cooked chicken, 97.4; ham, 98.1; potato salad, 100; liquid whole milk, 99.0; and canned mushrooms, 100. The data indicate that the SET 2 method is capable of detecting SET at 0.25 ng/g in cooked chicken, ham, potato salad, and canned mushrooms and at 0.5 ng/g in pasteurized liquid whole milk.
Development and Validation of an Agar Diffusion Assay for Determination of Ceftazidime in Pharmaceutical Preparations
Authors: Schmidt Cleber A , Carazzo Marcelly , Laporta Luciane V , Bittencourt Celso F , Santos Marcos R , Friedrich Milene
Published: February 2020

Ceftazidime (CFZ) is a broad spectrum parenterallactam antibiotic of the cephalosporin family. This paper reports the development and validation of an agar diffusion microbiological assay using the cylinder-plate method for determination of CFZ in powder for injection. The validation carried out yielded good results in terms of linearity, precision, accuracy, selectivity, and robustness. The assay is based on the inhibitory effect of CFZ upon the strain of Pseudomonas aeruginosa ATCC 27853 used as the test microorganism. The results of the assays were treated statistically by analysis of variance and were found to be linear (correlation coefficient = 0.999998) in the selected range of 8.032.0 g/mL; precise [repeatability: relative standard deviation (RSD) = 1.11; intermediate precision: between-day RSD = 1.37 and between-analyst RSD = 1.41]; and accurate. The selectivity of the bioassay was evaluated by analysis of degraded samples at 50C, and the results were compared with a pharmacopeial liquid chromatographic method at the time 0, 24, and 48 h. The results demonstrated the validity of the proposed bioassay, which allows reliable quantitation of CFZ in pharmaceutical samples and can be used as a useful alternative methodology for CFZ analysis in routine quality control.
Validation of the Normocythemic Mice Bioassay for the Potency Evaluation of Recombinant Human Erythropoietin in Pharmaceutical Formulations
Authors: Barth Thiago , Oliveira Paulo R , D'Avila Felipe B , Dalmora Srgio L
Published: February 2020

The normocythemic mice bioassay was validated for the potency evaluation of the recombinant human erythropoietin (rhEPO) against the European Pharmacopoeia Biological Reference Preparation for erythropoietin. The bioassays were performed in 8-week-old female BALB/c mice, which received multiple daily injections of standard or sample solutions (3 + 3), for 4 days. The blood sampling was performed 24 h after the last injection and the reticulocytes were counted by automated flow cytometry. Method validation investigated parameters such as linearity, precision, accuracy, specificity, and robustness, giving results within the acceptable range. The dose-response curve was linear in the concentration range of 164 international units (IU)/mL, and the value of the determination coefficient (r2) was 0.9708. The bioassay was applied for the potency evaluation of rhEPO pharmaceutical products containing alfa or beta forms, expressed in different cell lines, giving biological potencies within 82.79 and 119.70 of the stated potency. The precision index calculated by the weight for the independent assays was >247. The results demonstrated the validity of the bioassay for the potency assessment of pharmaceutical formulations contributing to ensure the therapeutic efficacy of the biological medicine.
Column High-Performance Liquid Chromatographic Determination of Norfloxacin and Its Main Impurities in Pharmaceuticals
Authors: Mielji Branislava , Popovi Gordana , Agbaba Danica , Markovi Slavko , Simonovska Breda , Vovk Irena
Published: February 2020

A gradient reversed-phase column high-performance liquid chromatographic method was developed for the detection and quantification of norfloxacin and its major impurities in norfloxacin-containing pharmaceuticals. Chromatographic separations were performed under the following experimental conditions: column, Zorbax SB RP-18 (5 m, 250 4.6 mm); injection volume, 20 L; mobile phase, 0.05 M NaH2PO4 (pH 2.5)acetonitrile (87 + 13) for 16 min and (58 + 42) for 9 min (stepwise gradient); and flow rate, 1.3 mL/min. All analyses were performed at 25C, and the eluate was monitored at 275 nm using a diode array detector. Linearity (correlation coefficient = 0.999), recovery (99.3101.8), relative standard deviation (0.20.7), and quantitation limit (0.120.47 g/mL) were evaluated and found to be satisfactory. The method is simple, rapid, and convenient for purity control of norfloxacin in both raw materials and dosage forms.
Improved Extraction Method for the Determination of Iron, Copper, and Nickel in New Varieties of Sunflower Oil by Atomic Absorption Spectroscopy
Authors: Ansari Rehana , Kazi Tasneem G , Jamali Mohammad K , Arain Mohammad B , Sherazi Syed T , Jalbani Nusrat , Afridi Hassan I
Published: February 2020

A simple and fast procedure is proposed for the extraction of iron (Fe), copper (Cu), and nickel (Ni) in 16 varieties of sunflower seed oil samples using an ultrasonic bath. The experimental parameters of the ultrasonic-assisted extraction (UAE) method were optimized to improve the sensitivity and detect the metals at trace levels in minimum time. Conventional wet acid digestion method was used for comparative purposes. The optimum recovery of all 3 metals was obtained by UAE for 7 min, while the separation of aqueous and organic phases after extraction using centrifugation (UAE-2) required 3 min, as compared to the conventional equilibration method (UAE-1) that required 90 min. The respective recoveries of Cu, Fe, and Ni obtained with UAE-2 were in the range of 95.897.5, 93.598.3, and 95.698.2, respectively, for different varieties of sunflower oil samples. Accuracy was determined by the standard addition method. Under the optimum operating conditions, the limits of detection obtained from the standard addition curves were 21.7, 20.4, and 35.6 ng/mL for Fe, Cu, and Ni, respectively. The fact that all varieties of sunflower oil contain significant amounts of Fe, Cu, and Ni indicates the deterioration of sunflower oil quality immediately after extraction from seeds, which poses a threat to oil quality and human health.
Single-Laboratory Validation of a Method for the Determination of Furan in Foods by Using Headspace Gas Chromatography/Mass Spectrometry, Part 2Low-Moisture Snack Foods
Authors: Nyman Patricia J , Morehouse Kim M , Perfetti Gracia A , Diachenko Gregory W , Holcomb Jim R
Published: February 2020

In 2004, a quantitative headspace (HS) gas chromatographic/mass spectrometric method was developed and used to determine furan in approximately 300 foods. This method was modified and validated for the determination of furan in low-moisture snack foods. The modifications include a smaller test portion size and lower HS oven temperature. The limits of detection ranged from 0.4 ng/g in graham crackers to 4.4 ng/g in pretzels. Recoveries from samples fortified at 0.5, 1, 2, and 3 times the levels of incurred furan found in the samples ranged from 96 to 102, and HorRat values showed that the recovery data met the criteria for repeatability. The modified method was shown to be reliable for the determination of furan in foods when test portions were equilibrated for 30 min in a 60C HS oven. The modified method was used to conduct a survey of furan in 22 low-moisture snack foods. All of the samples were found to contain furan ranging from 3.7 ng/g in graham crackers to 60 ng/g in corn chips. Results from the survey were consistent with results obtained for similar snack foods analyzed by a U.S. Food and Drug Administration field laboratory.
Development and Validation of a Stability-Indicating Column High-Performance Liquid Chromatographic Assay Method for Determination of Nebivolol in Tablet Formulation
Authors: Kachhadia Pankaj K , Doshi Ashish S , Joshi Hitendra S
Published: February 2020

A simple, precise, and accurate isocratic reversed-phase (RP) stability-indicating column high-performance liquid chromatographic (HPLC) assay method was developed and validated for determination of nebivolol in solid pharmaceutical dosage forms. Isocratic RP-HPLC separation was achieved on a Phenomenex Luna C8 (2) column (250 mm 4.6 mm id, 5 m particle size) using mobile phase composed of acetonitrilepH 3.5 phosphate buffer (35 + 65, v/v) at a flow rate of 1.0 mL/min, and detection was performed at 280 nm using a photodiode array detector. The drug was subjected to oxidation, hydrolysis, photolysis, and heat to apply stress conditions. The method was validated for specificity, linearity, precision, accuracy, robustness, and solution stability. The method was linear in the drug concentration range of 40160 g/mL with a correlation coefficient of 0.9999. The repeatability relative standard deviation (RSD) for 6 samples was 0.69, and the intermediate precision (RSD) for 6 samples was 1.39. The accuracy (recovery) was between 98.57 and 99.55. Degradation products produced as a result of stress studies did not interfere with detection of nebivolol, and the assay can thus be considered stability-indicating.
Development and Validation of a Liquid Chromatographic/Tandem Mass Spectrometric Method for Determination of Tetracycline in Human Plasma: Application to Bioequivalence Study
Authors: Brum Liberato , Pugens Ana Maria , Pritsch Mariely Camila , Mantovani Patricia Bertuol , dos Santos Maurício Bedim , Manfio Josélia Larger
Published: February 2020

A fast, sensitive, and specific liquid chromatographic/tandem mass spectrometric method was developed and validated for determination of tetracycline in human plasma. Tetracycline and oxytetracycline [internal standard (IS)] were extracted from the plasma by protein precipitation. The mobile phase consisted of acetonitrileformic acid 0.1 (48 + 52, v/v), run at a flow rate of 1 mL/min (split 1:5). Detection was performed by positive electrospray ionization in multiple reaction monitoring mode, monitoring the transitions 444.8 > 410.0 and 461.0 > 426.0 for tetracycline and IS, respectively. The analysis was performed in 3.5 min and the method was linear in the plasma concentration range of 506000 ng/mL. The mean extraction recoveries for tetracycline and IS from plasma were 92.14 and 94.04, respectively. Method validation investigated parameters such as the linearity, precision, accuracy, specificity, and stability, giving results within the acceptable range. The proposed method was successfully applied for determination of tetracycline in human plasma samples to support bioequivalence studies.
Development of a New High-Performance Liquid Chromatographic Method for the Determination of Ceftazidime
Authors: de Haro Moreno Andréia , Salgado Hérida Regina Nunes
Published: February 2020

A rapid, accurate, and sensitive high-performance liquid chromatographic (HPLC) method was developed and validated for the determination of ceftazidime in pharmaceuticals. The method validation parameters yielded good results and included range, linearity, precision, accuracy, specificity, and recovery. The excipients in the commercial powder for injection did not interfere with the assay. Reversed-phase chromatography was used for the HPLC separation on a Waters C18 (WAT 054275; Milford, MA) column with methanolwater (70 + 30, v/v) as the mobile phase pumped isocratically at a flow rate of 1.0 mL/min. The effluent was monitored at 245 nm. The calibration graph for ceftazidime was linear from 50.0 to 300.0 g/mL. The values for interday and intraday precision (relative standard deviation) were <1. The results obtained by the HPLC method were calculated statistically by analysis of variance. We concluded that the HPLC method is satisfactory for the determination of ceftazidime in the raw material and pharmaceuticals.
Fatty Acid Profile of Canadian Dairy Products with Special Attention to the trans-Octadecenoic Acid and Conjugated Linoleic Acid Isomers
Authors: Mendis Sanjaya , Cruz-Hernandez Cristina , Ratnayake Walisundera M N
Published: February 2020

Current scientific evidence indicates that consumption of industrial trans fatty acids (TFA) produced via partial hydrogenation of vegetable oils increases the risk of coronary heart disease. However, some studies have suggested that ruminant TFA, especially vaccenic acid (VA or 11t-18:1) and rumenic acid (RA or 9c,11t-18:2), which is a conjugated linoleic acid (CLA) isomer, may have potential beneficial health effects for humans. To date, no concerted effort has been made to provide detailed isomer composition of ruminant TFA and CLA of Canadian dairy products, information that is required to properly assess their nutritional impacts. To this end, we analyzed the fatty acid profile of popular brands of commercial cheese (n = 17), butter (n = 12), milk (n =8), and cream (n = 4) sold in retail stores in Ottawa, Canada, in 20062007 by silver nitrate thin-layer chromatography and gas liquid chromatography. The average total TFA content of cheese, butter, milk, and cream samples were 5.6, 5.8, 5.8, and 5.5 of total fatty acids, respectively. VA was the major trans-octadecenoic acid (18:1) isomer in all the Canadian dairy samples with average levels of (as total trans-18:1) 33.9 in cheese, 35.6 in butter, 31.0 milk, and 30.1 in cream. The different dairy products contained very similar levels of CLA, which ranged from 0.5 to 0.9 of total fat. RA was the major CLA isomer of all the dairy products, accounting for 82.483.2 of total CLA. There were no significant differences (P > 0.05) in the fatty acid profile between the 4 different dairy groups, which suggests lack of processing effects on the fatty acid profile of dairy fat.
Proficiency Testing Program for the Determination of Total Arsenic, Cadmium, and Lead in Seawater Shrimp
Authors: Kong Mei-Fung , Chan Serena , Wong Yiu-Chung
Published: February 2020

The proficiency testing (PT) program for 97 worldwide laboratories for determining total arsenic, cadmium, and lead in seawater shrimp under the auspices of the Asia-Pacific Laboratory Accreditation Cooperation (APLAC) is discussed. The program is one of the APLAC PT series whose primary purposes are to establish mutual agreement on the equivalence of the operation of APLAC member laboratories and to take corrective actions if testing deficiencies are identified. Pooled data for Cd and Pb were normally distributed with interlaboratory variations of 21.9 and 34.8, respectively. The corresponding consensus mean values estimated by robust statistics were in good agreement with those obtained in the homogeneity tests. However, a bimodal distribution was observed from the determination of total As, in which 14 out of 74 participants reported much smaller values (0.4826.4 mg/kg) as compared with the mean values of 60.9 mg/kg in the homogeneity test. The use of consensus mean is known to have significant deviation from the true value in bi- or multimodal distribution. Therefore, the mode value, a better estimate of central tendency, was chosen to assess participants' performance for total As. Estimates of the overall uncertainty from participants varied in this program, and some were recommended to acquire more comprehensive exposure toward important criteria as stipulated in ISO/IEC 17025.
Identification of Food-Derived Bioactive Peptides in Blood and Other Biological Samples
Authors: Sato Kenji , Iwai Koji , Aito-Inoue Misako
Published: February 2020

Recent studies have demonstrated the presence of food-derived peptides in human blood after ingestion of enzymatic hydrolysates of food proteins, while most peptides in food are degraded into amino acids during digestion and absorption. To capture and clarify the food-derived peptides in blood, solid-phase extraction (SPE) using a mini-spin column packed with a strong cation exchanger was developed. This technique allows the use of a nonvolatile acid such as trichloroacetic acid, a strong protein denaturant, for the deproteinizing procedure. To improve resolution of hydrophilic peptide and increase specificity and sensitivity in the detection of peptide by reversed-phase high-performance liquid chromatography (RP-HPLC) after subfractionation by size-exclusion chromatography (SEC), peptides are derivatized with phenyl isothiocyanate. The resultant phenyl thiocarbamyl (PTC)-peptides can be resolved with high resolution and sensitivity by RP-HPLC. By comparing chromatograms of PTC derivatives from blood before and after ingestion of a peptide sample, food-derived peptide can be detected. The isolated PTC-peptide can be applied to a peptide sequencer based on the Edman degradation reaction.
Determination of Etofibrate, Fenofibrate, and Atorvastatin in Pharmaceutical Preparations and Plasma Using Differential Pulse Polarographic and Square Wave Voltammetric Techniques
Authors: Korany Mohamed A , Hewala Ismail I , Abdel-Hay Karim M
Published: February 2020

Etofibrate, fenofibrate, and atorvastatin were determined in their pharmaceutical preparations and human plasma using differential pulse polarographic and square wave voltammetric techniques by reduction at a dropping-mercury working electrode versus Ag/AgCl reference electrode. The reversibility of the electrode reactions was tested using cyclic voltammetry, and they were found to be irreversible reduction reactions. Optimum conditions such as pH, scan rate, and pulse amplitude were studied, and validation of the proposed methods was performed. The proposed methods proved to be accurate, precise, robust, and specific for determination of the 3 drugs. The relative standard deviation values were <2, indicating that these methods are precise. Limits of detection and quantitation were in the ranges of 0.0370.21 and 0.120.71 g/mL, respectively, indicating high sensitivity.
Comparison of Petrifilm Staph Express Count System with the Bacteriological Analytical Manual Direct-Plating Method for Enumeration of Staphylococcus aureus in Artificially Contaminated Hard Cheese
Authors: Fedio Willis M , Wendakoon Chitra N , Zapata Ruben , Carrillo Christina , Browning Paul
Published: February 2020

The 3M Petrifilm Staph Express Count System was compared with the U.S. Food and Drug Administration's Bacteriological Analytical Manual (BAM) direct-plate count method for the enumeration of Staphylococcus aureus in 6 types of artificially contaminated hard cheese (Asiago, Cheddar, Gruyre, Parmesan, Romano, and Swiss). Five different samples of each cheese type were inoculated with S. aureus (ATCC 25923) to achieve low, medium, and high inoculum levels. S. aureus was enumerated by the Petrifilm and BAM methods, and the results were compared. Multivariate analysis of variance revealed no significant differences (P <0.05) between the 2 methods. The Petrifilm method compared favorably with the BAM procedure. The rapid method was more convenient to use, considerably faster, and less expensive to perform than the BAM method.
Simultaneous Determination of Bioactive Xanthone Glycosides and Norlignans from Ethanolic Extract of Anemarrhena asphodeloides by Liquid Chromatography
Authors: Islam M Nurul , Yoo Hye Hyun , Lee Jun , Nam Joo Won , Seo Eun Kyoung , Jin Changbae , Kim Dong-Hyun
Published: February 2020

The rhizomes of Anemarrhena asphodeloides Bunge (Liliaceae) are prescribed as crude drugs in herbal medication for the treatment of various diseases such as diabetes, inflammation, and platelet aggregation inhibition. A simple, sensitive, and precise reversed-phase liquid chromatographic method was developed to study the quantitative determination of 5 bioactive compounds from these rhizomes, namely, neomangiferin, mangiferin, isomangiferin, nyasol, and methylnyasol. Chromatographic analysis was performed on Capcell Pak C18 column (150 4.6 mm, 3 m) with a mobile phase consisting of acetonitrile, methanol, and 0.1 formic acid at a flow rate of 1.00 mL/min. Quantitation was performed using a UV-visible detector at 260 nm. The method for the determination of reported medicinal agents was accurate and reproducible. Excellent linear behavior was observed over the investigated concentration range of 2.5100.0 g/mL for neomangiferin; 1.560.0 g/mL for mangiferin; 0.520.0 g/mL for nyasol; and 0.220.0 g/mL for methylnyasol; correlation coefficient >0.99. The intraday and interday precision over the concentration range of compounds was <6.6 (relative standard deviation) and accuracy was between 94.9 and 109.3. This method can be successfully applied for the analysis of medicinal compounds from the ethanolic extract of A. asphodeloides Bunge.
Validation of a High-Performance Liquid Chromatographic Method with UV Detection for the Determination of Ethopabate Residues in Poultry Liver
Authors: Granja Rodrigo H M M , Niño Alfredo M Montes , Zucchetti Roberto A M , Niño Rosario E Montes , Salerno Alessandro G
Published: February 2020

Ethopabate is frequently used in the prophylaxis and treatment of coccidiosis in poultry. Residues of this drug in food present a potential risk to consumers. A simple, rapid, and sensitive column high-performance liquid chromatographic (HPLC) method with UV detection for determination of ethopabate in poultry liver is presented. The drug is extracted with acetonitrile. After evaporation, the residue is dissolved with an acetonehexane mixture and cleaned up by solid-phase extraction using Florisil columns. The analyte is then eluted with methanol. LC analysis is carried out on a C18 5 m Gemini column, 15 cm 4.6 mm. Ethopabate is quantified by means of UV detection at 270 nm. Parameters such as decision limit, detection capability, precision, recovery, ruggedness, and measurement uncertainty were calculated according to method validation guidelines provided in 2002/657/EC and ISO/IEC 17025:2005. Decision limit and detection capability were determined to be 2 and 3 g/kg, respectively. Average recoveries from poultry samples fortified with 10, 15, and 20 g/kg levels of ethopabate were 100105. A complete statistical analysis was performed on the results obtained, including an estimation of the method uncertainty. The method is to be implemented into Brazil's residue monitoring and control program for ethopabate.
Column Liquid Chromatography-Ultraviolet and Column Liquid Chromatography/Mass Spectrometry Evaluation of Stress Degradation Behavior of Escitalopram Oxalate
Authors: Dhaneshwar Sunil R , Mahadik Mahadeo V , Kulkarni Mahesh J
Published: February 2020

The objective of this work was to study the degradation behavior of escitalopram oxalate under different International Conference on Harmonization (ICH)-recommended stress conditions by column liquid chromatography (LC)-UV and LC/mass spectrometry (LC/MS) and to establish a validated stability-indicating LC assay method. Escitalopram oxalate was subjected to stress conditions of hydrolysis, oxidation, photolysis, and thermal decomposition. Extensive degradation was found to occur in alkaline medium. Mild degradation was observed in acidic and oxidative conditions. Escitalopram oxalate was stable to neutral, photolytic, and thermal stress. Successful separation of the drug from degradation products formed under stress conditions was achieved on a PerfectSil-100 ODS-3 column [C18 (5 m, 25 cm 4.6 mm id)] using methanol0.01 M acetate buffer pH 3.8 adjusted with acetic acid (45 + 55) as the mobile phase. The flow rate was 1 mL/min, and the detection wavelength was 239 nm. The method was validated according to ICH guidelines. Major degradation products formed in hydrolysis and oxidative conditions were isolated, and structural elucidation of degradation products was done by LC/MS and infrared spectrometry studies. The major hydrolysis degradation product was confirmed as 1-(3-dimethylaminopropyl)-1-(4-fluoro- phenyl)-1,3dihydroisobenzofuran-5-carboxylic acid, and the major oxidative degradation product was confirmed as 1-{[3-dimethylamino(oxide)- propyl]-1-(4-fluro-phenyl)}-1,3-dihydro-isobenzofuran- 5-carbonitrile.
TEMPO® TVC for the Enumeration of Aerobic Mesophilic Flora in Foods: Collaborative Study
Authors: Crowley Erin S , Bird Patrick M , Torontali Marianne K , Agin James R , Goins David G , Johnson Ronald ,   Collaborators:, Achen M , Balogh J , Barket D , Boatwright A , Clark M , Colon-Reveles J , Dixon K , Gorman; M , Hanson P , Husby G , Kelly M , Kim S , Koschmann C , Laflamme L , Larson C , Manner K , McCallum K , McClure; H , McMahon W , Mills J , Mohnke F , Moon B , Murphy M , Post L , Quast V , Riva J , Zadeh K , Zadeh S
Published: February 2020

The automated system for enumeration of total viable count (TVC) in foods, TEMPO® TVC, uses a dehydrated culture medium and an enumeration card containing 48 wells across 3 different dilutions for the automatic determination of the most probable number (MPN). The alternative method was compared in a multilaboratory collaborative study to AOAC Method 966.23 for determination of aerobic plate count for nondairy products and the Standard Methods for the Examination of Dairy Products (SMEDP) Standard Plate Count for dairy products. Five food types, raw ground beef, raw ground chicken, cooked whitefish fillets, bagged lettuce, and milk, were analyzed for TVC by 14 collaborating laboratories throughout the United States and Canada. Three lots of naturally contaminated food products representing a wide range of counts were tested for each of the 5 food types. The study demonstrated that the overall repeatability, reproducibility, and mean log counts of the TEMPO TVC method were statistically comparable to those of the 2 standard methods at the 5 level.
Assay of Florfenicol in Swine Feed: Interlaboratory Study
Authors: Hayes John M , Gilewicz Rosalia , Freehauf Keith , Fetter Mary
Published: February 2020

Nuflor (florfenicol) Premix for Swine was recently approved by the U.S. Food and Drug Administration (FDA) for control of swine respiratory disease (SRD). A simple method for the assay of florfenicol in Type C medicated swine feeds was recently evaluated as part of a 4-laboratory study. Florfenicol is extracted from ground feed with acetonitrilewater by shaking and sonication. An Envi-Carb solid-phase extraction cartridge is used to clean up the extract, retaining matrix interferences while allowing florfenicol to elute. The collected eluent is diluted and injected into a reversed-phase liquid chromatographic system. Samples are quantitated by external standard analysis versus multilevel calibration solutions. The procedure is suitable for the quantification of swine feeds in mash or pellet form medicated with 100300 mg/kg florfenicol. The interlaboratory study was conducted according to Guidance 136 issued by the FDA Center for Veterinary Medicine. The feeds used to evaluate method performance represented different feed compositions (starter and finisher) and manufacturers. The sponsor and 3 independent laboratories obtained mean recoveries (SD) from fortified swine feeds of 100.7 (2.0), 99.6 (2.8), 98.8 (1.4), and 99.3 (1.7), respectively. Excellent agreement of the results of the assay of blind samples of commercial swine mash and pelleted feeds between laboratories demonstrates that the method is rugged and reproducible.
Factors Affecting Accuracy and Time Requirements of a Glucose Oxidase–Peroxidase Assay for Determination of Glucose
Authors: Hall Mary B , Keuler Nicholas S
Published: February 2020

Accurate and rapid assays for glucose are desirable for analysis of glucose and starch in food and feedstuffs. An established colorimetric glucose oxidaseperoxidase method for glucose was modified to reduce analysis time and evaluated for factors that affected accuracy. Time required to perform the assay was reduced by approximately 40 by decreasing incubation time and removing steps that do not affect absorbance. Although linear regressions of absorbance and glucose concentrations of standard solutions exceeded R2 of 0.9997, evaluation of sum of squared residuals, root mean squared error, and significance of the quadratic term indicated that the curves were approximately quadratic in form. Inadequate equilibration of glucose anomers did not appear to be the issue. Historic data suggest that the standard curve is inherently nonlinear. Quadratic curves predicted standard solution glucose concentrations more accurately than did linear forms; overestimations at the midpoint of the curve averaged 0.04, 0.48, and 0.92 for quadratic and linear equations calculated from 5 standard solutions and a linear equation calculated from the 0 and most concentrated standard solution, respectively. A hydrophilic antioxidant at levels no greater than 10 mol ascorbic acid/0.10 g air-dried sample did not affect absorbance values.