bluuebunny/crossref_metadata_2025 huggingface dataset:
USDA FSIS and FDA BAM Culture Methods BBL CHROMagar Salmonella Prepared Plated and Difco Dehydrated Culture Media
Authors: Ritter Vicki , Dick Nancy
Published: February 2020

BBL and Difco CHROMagar Salmonella (CS) was evaluated internally and externally for the recovery of Salmonella in raw chicken, raw ground beef, raw fish, lettuce, and shell eggs. The raw chicken and ground beef were processed according to the U.S. Department of Agriculture, Food Safety and Inspection Service reference methods. The raw fish, lettuce, and shell eggs were processed according to the U.S. Food and Drug Administration, Bacteriological Analytical Manual procedures. Only raw chicken was found to be naturally contaminated with Salmonella; all other matrixeswere seededwith an appropriate dilution of organism to achieve fractionally positive results. Salmonella strains were permitted to equilibrate with the culture-negative matrixes for 48 h at 4C. Twenty 25 g samples of each food matrix plus 5 uninoculated samples were processed. CS prepared plates (CS PPM) and laboratory prepared plates from dehydrated culture media (CS DCM) were evaluated with the reference method media. A total of 16 positive cultures were obtained from the raw chicken samples, 17 in the raw ground beef, 18 in the raw fish and lettuce, and 11 in the shell eggs. A Chi-square analysis was performed on each of the food matrixes. BBL CS produced comparable results with the reference methods on all matrixes, resulting in a method agreement of 100 based on the Chi-square results. In testing known isolates the sensitivity and specificity was determined to be 94. Specificity improved to 98 when tetrathionate broth enrichment was used. A negative- and false-positive rate of 6 was found with known isolates. No false negatives were found in testing the food matrixes. The performance of the CS prepared plate and laboratory prepared plate was identical.
Addendum: ISO Culture Methods Comparative Testing of BBL CHROMagar Salmonella Prepared Plated Culture Medium
Authors: Ritter Vicki , Dick Nancy
Published: February 2020

BBL CHROMagar Salmonella (CS) was evaluated for the detection of Salmonella species compared to the International Organization for Standardization (ISO) 6579:2002 reference method media. Raw chicken, raw ground beef, raw fish, lettuce, and shell eggs were evaluated by an independent laboratory. Raw chicken was found to be naturally contaminated with Salmonella; all other matrixes were seeded with Salmonella at a low level. Four Salmonella serovars were used for seeding the food matrixes. A total of 120 food samples were analyzed. The detection and isolation of Salmonella on CS was compared to the ISO culture methods reference media, using the recommended pre-enrichments and selective enrichments. BBL CS produced results comparable to those of the reference methods on all matrixes, resulting in a method agreement of 100 based on the Chi-square results. Known isolates were tested and had a sensitivity of 96.8 and specificity of 94. No false negatives were found in testing the food matrixes. The results of this study demonstrate that BBL CS is an effective medium for the recovery and detection of Salmonella in raw chicken, raw ground beef, raw fish, lettuce, and shell eggs using ISO method 6579.
Simultaneous Determination of Cholecalciferol (Vitamin D3) and Ergocalciferol (Vitamin D2) in Foods by Selected Reaction Monitoring
Authors: Dimartino Gianluca
Published: February 2020

Cholecalciferol (vitamin D3) and ergocalciferol (vitamin D2) were determined simultaneously by selected reaction monitoring (SRM) mass spectrometry for different food matrixes. A small amount of starting sample was saponified and extracted before injection into a linear ion trap mass spectrometer equipped with an atmospheric pressure chemical ionization source. Dihydrotachysterol, which is absent from food and has a structure similar to that of vitamins D3 and D2, was used as an internal standard. Calibration curves for the 2 vitamins showed linearity with R2 values of 0.9999 and 0.9989 for vitamins D3 and D2, respectively. Limits of detection for vitamins D3 and D2 were 0.5 ng/g (1.3 pmol/g) and 1.75 ng/g (4.4 pmol/g) and limits of quantitation were 1.25 ng/g (3.24 pmol/g), and 3.75 ng/g (9.45 pmol/g), respectively. Accuracy and precision of the method were tested with the infant formula reference standard of the National Institute of Standards and Technology, which showed a relative standard deviation of 6. Recoveries ranged from 95 to 105. Several food products were tested with AOAC Method 982.29, which is currently in use for vitamins D3 and D2, and results were comparable within 6.
Determination of Thioglycolic Acid in Hair-Waving Products by Disposable Electrochemical Sensor Coupled with High-Performance Liquid Chromatography
Authors: Zen Jyh-Myng , Yang Hsueh-Hui , Chiu Mei-Hsin , Chen Yu-Ju , Shih Ying
Published: February 2020

A disposable electrochemical sensor coupled with high-performance liquid chromatography (HPLC) was developed for the determination of thioglycolic acid (TGA) in commercial hair-waving products. The quantitative determination of TGA was first investigated by using a preanodized () screen-printed carbon electrode (SPCE). Because of the electrocatalytic effect of the SPCE, the peak potential (Epa) was shifted less positively as the current magnitude increased. HPLC was used in this study to eliminate interference from the matrix of real samples. The effects of various parameters, such as preanodization potential, preanodization time, solution pH, detection potential, and mobile phase, were studied in detail. Under optimized conditions, the linear range for TGA is up to 20 ppm, correlation coefficient (r2) 0.998, with a detection limit of 0.042 ppm (signal-to-noise ratio 3). The practical application of the proposed method was demonstrated by the determination of TGA concentration in commercial hair-waving products.
Infrared Authentication of Ginseng Species: The Use of the 2-6PC Rule
Authors: Yap Kevin Yi-Lwern , Henglai Tommy Kok , Chan Sui Yung , Lim Chu Sing
Published: February 2020

The quality of herbal products is important for ensuring efficacy and consumer safety. Traditional methods of authenticating herbs like ginseng via their morphology are hardly reliable. Different chemical constituents in herbs like ginseng tend to exhibit characteristic IR fingerprints that enable their identification. We previously introduced an IR-based protocol known as the 2-6PC rule to categorize and identify ginseng and its products, as well as distinguishing it from morphological fakes. Here, we describe the use of this rule as a rapid and effective means of analyzing the IR spectral fingerprints of the biologically active components of ginseng, as well as distinguishing among its species. Our results show that Panax ginseng, P. quinquefolius, and P. notoginseng can be differentiated from each other. Our results also indicate the presence of starch, carbohydrates, calcium oxalate, and ginsenosides Re and Rg1 in commercial ginseng roots sold in Singapore. This work effectively demonstrates the usefulness of the 2-6PC rule as a rapid screening tool in the authentication of ginseng species.
Rapid Planar Chromatographic Analysis of 25 Water-Soluble Dyes Used as Food Additives
Authors: Morlock Gertrud E , Oellig Claudia
Published: February 2020

A rapid planar chromatographic method for identification and quantification of 25 water-soluble dyes in food was developed. In a horizontal developing chamber, the chromatographic separation on silica gel 60F254 high-performance thin-layer chromatography plates took 12 min for 40 runs in parallel, using 8 mL ethyl acetatemethanolwateracetic acid (65 + 23 + 11 + 1, v/v/v/v) mobile phase up to a migration distance of 50 mm. However, the total analysis time, inclusive of application and evaluation, took 60 min for 40 runs. Thus, the overall time/run can be calculated as 1.5 min with a solvent consumption of 200 L. A sample throughput of 1000 runs/8 h day can be reached by switching between the working stations (application, development, and evaluation) in a 20 min interval, which triples the analysis throughput. Densitometry was performed by absorption measurement using the multiwavelength scan mode in the UV and visible ranges. Repeatabilities [relative standard deviation (RSD), 4 determinations] at the first or second calibration level showed precisions of mostly 2.7, ranging between 0.2 and 5.2. Correlation coefficient values (R 0.9987) and RSD values (4.2) of the calibration curves were highly satisfactory using classical quantification. However, digital evaluation of the plate image was also used for quantification, which resulted in RSD values of the calibration curves of mostly 3.0, except for two 6.0. The method was applied for the analysis of some energy drinks and bakery ink formulations, directly applied after dilution. By recording of absorbance spectra in the visible range, the identities of the dyes found in the samples were ascertained by comparison with the respective standard bands (correlation coefficients 0.9996). If necessary for confirmation, online mass spectra were recorded within a minute.
Determination of Psoralen and Plumbagin from Its Polyherbal Oil Formulations by an HPTLC Densitometric Method
Authors: Dubey Nidhi , Dubey Nitin , Mehta Rajendra , Saluja Ajay Kumar
Published: February 2020

Many polyherbal oil formulations in Indian and Chinese traditional systems of medicine used for control of skin diseases contain seeds of Psoralea corylifolia and roots of Plumbago zeylanica L. Psoralen and plumbagin are the reliable markers for Ps. corylifolia and Pl. zeylanica, respectively. However, no attempt is made to standardize the polyherbal oil formulations containing Ps. corylifolia and Pl. zeylanica in terms of their active ingredients or marker compounds. In this paper, a simple, rapid, and sensitive HPTLC method is described for the first time to identify and quantify psoralen and plumbagin from such polyherbal oil formulations. The methanolic extract of oil formulations was used for analysis of markers. Psoralen gives a sharp UV absorbance peak at 302 nm and plumbagin at 275 nm. Good resolution of psoralen (Rf = 0.37) and plumbagin (Rf = 0.77) was attained using tolueneethyl acetate (7.5 + 2.5, v/v) mobile phase. The method was validated in terms of calibration curve, limits of detection and quantification, precision, accuracy, and robustness following a standard protocol. Polyherbal oil formulations were analyzed with reasonable accuracy, and no matrix interference was observed. The method developed can be used for marker-based quality assurance of oil formulations containing Ps. corylifolia and Pl. zeylanica as one active ingredient.
Evaluation of a Revised U.S. Food and Drug Administration Method for the Detection and Isolation of Enterobacter sakazakii in Powdered Infant Formula: Precollaborative Study
Authors: Chen Yi , Hammack Thomas S , Song Kwang-Young , Lampel Keith A
Published: February 2020

A revised U.S. Food and Drug Administration (FDA) method for the detection and isolation of Enterobacter sakazakii in powdered infant formula was developed based on real-time PCR technology complemented by culture isolation on chromogenic agars. A validation study was conducted to compare the revised FDAmethod to the reference FDAmethod. Casein and soy powdered infant formula inoculated with morphologically typical and atypical strains of E. sakazakii were analyzed. Valid results were obtained from 360 test portions and controls and showed that the revised FDAmethod is significantly better (P < 0.05) than the reference FDAmethod for the detection of typical E. sakazakii strains and the two methods are equivalent for the detection of atypical E. sakazakii strains.
Genotyping of Strawberry (Fragaria ananassa Duch.) Cultivars by DNA Markers: Interlaboratory Study
Authors: Kunihisa Miyuki , Ueda Hiroshi , Fukino Nobuko , Matsumoto Satoru ,   Collaborators:, Akasaki T , Amagai M , Arakawa K , Asami I , Asao H , Chiba N , Hirano M , Ishikawa M , Kai H , Kitahara K , Koshikawa K , Maeda F , Nishikawa T , Niwa Y , Noda T , Nomura Takahiro , Nomura Tomofumi , Numata S , Osaki M , Saegusa T , Shimizu K , Shimomura K , Takemoto K , Takeuchi Y , Tasaki K , Yamamoto Y , Yasuda M , Yoshimura Y
Published: February 2020

Fourteen Japanese laboratories validated the reproducibility of genotyping by 25 cleavage amplified polymorphic sequence (CAPS) markers for discrimination of strawberry (Fragaria ananassa Duch.) cultivars. Both the sensitivity and specificity rate of 12 markers were 100, those of another 12 were >95, and those of 1 were >90. These results indicate that the method of genotyping by the CAPS markers was highly reproducible and could provide a useful basis for practical identification of strawberry cultivars. This is the first report of the statistical validation of crop genotyping by DNA markers.
Stability-Indicating Reversed-Phase Liquid Chromatographic Methods for the Determination of Aconitine and Piperine in a Polyherbal Formulation
Authors: Rai Pallavi , Pathak Ashutosh , Rajput Sadhana J
Published: February 2020

Simple and rapid stability-indicating HPLC methods were developed for the individual analysis of aconitine (ACN) and piperine (PIN) in Mahamrutynjaya rasa, an herbal dosage form containing Aconitum ferox, Piper nigrum, and Piper longum in combination. Separation of the ACN from its major and minor degradation products was successfully achieved on a reversed-phase C18 column (250 4.6 mm id, 5 m particle size), with isocratic elution using a mixture of acetonitrileKH2PO4 buffer (10 mM, pH 8 0.1; 50 + 50, v/v) at flow rate of 0.7 mL/min with UV detection at 227 nm. PIN separation was performed on a reversed-phase C18 column (250 4.6 mm id, 5 mm particle size), with isocratic elution in acetonitrileKH2PO4 buffer (10 mM, pH 7 0.1; 35 + 65, v/v) at a flow rate of 1 mL/min with UV detection at 343 nm. The methods were validated with respect to linearity, precision, accuracy, specificity, system suitability, and robustness. The responses were linear in the drug concentration range of 10100 g/mL for both ACN and PIN. The percent recoveries of both the markers from a mixture of degradation products were in the range between 98101. The utility of the procedures was verified by their application to marketed formulations that were subjected to accelerated degradation studies. The methods could distinctly separate the drug and degradation products. The products formed in the marketed tablets were similar to those formed in the laboratory during stress studies.
USDA FSIS, FDA BAM, AOAC, and ISO Culture Methods BD BBL CHROMagar Listeria Media
Authors: Ritter Vicki , Kircher Susan , Sturm Krista , Warns Patty , Dick Nancy
Published: February 2020

BBL CHROMagar Listeria Media (CL) was evaluated for detection of Listeria monocytogenes in raw ground beef, smoked salmon, lettuce, and Brie cheese. The recovery of L. monocytogenes on CL was compared to the U.S. Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM), U.S. Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS), AOAC, and International Organization for Standardization (ISO) reference-plated media using the recommended pre-enrichments and selective enrichments. Of the 265 food samples tested, 140 were tested using BAM, USDA, or AOAC methods and 125 were tested using ISO methods. CL produced comparable results with the reference methods on all matrixes with a sensitivity of 99.3 and a specificity of 100. No false negatives were found in testing the food matrixes. There was no statistical difference in recovery based on Chi-square analysis. Known isolates were evaluated, and CL had a sensitivity and specificity of 100. The results of this study demonstrate that CL is an effective medium for the recovery and detection of L. monocytogenes in raw ground beef, smoked salmon, lettuce, and Brie cheese using FDA BAM, USDA FSIS, AOAC, and ISO culture methods.
USDA FSIS, FDA BAM, and ISO Culture Methods BD BBL CHROMagar O157 Media
Authors: Ritter Vicki , Kircher Susan , Dick Nancy
Published: February 2020

BBL CHROMagar O157 media (CO) was evaluated for detection of Escherichia coli O157:H7 in raw ground beef and unpasteurized apple cider. The recovery of E. coli O157:H7 on CO was compared to the U.S. Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM), U.S. Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS), and International Organization for Standardization (ISO) reference-plated media using the recommended enrichment broths. Of the 180 food samples tested, 45 were tested using BAM, 45 using the USDA method, and 90 using the ISO method. CO produced comparable results with the reference methods on all matrixes with a sensitivity of 100 and a specificity of 100. No false negatives were found in testing the food matrixes. There was no statistical difference in recovery based on Chi-square analysis. Method agreement for raw ground beef was 85 for the USDA FSIS method and 95 for the ISO method. Method agreement for unpasteurized apple cider was 100 for the ISO and FDA BAM methods. In all cases where method agreement was <100, CO detected more positives than the reference method media. Evaluation of known isolates on CO in inclusivity and exclusivity testing had a sensitivity and specificity of 100. The results of this study demonstrate that CO is an effective medium for the recovery and detection of E. coli O157:H7 in raw ground beef and unpasteurized apple cider using FDA BAM, USDA FSIS, and ISO methods.
Typing Methods for the Plague Pathogen, Yersinia pestis
Authors: Lindler Luther E
Published: February 2020

Phenotypic and genotypic methodologies have been used to differentiate the etiological agent of plague, Yersinia pestis. Historically, phenotypic methods were used to place isolates into one of three biovars based on nitrate reduction and glycerol fermentation. Classification of Y. pestis into genetic subtypes is problematic due to the relative monomorphic nature of the pathogen. Resolution into groups is dependent on the number and types of loci used in the analysis. The last 510 years of research and analysis in the field of Y. pestis genotyping have resulted in a recognition by Western scientists that two basic types of Y. pestis exist. One type, considered to be classic strains that are able to cause human plague transmitted by the normal flea vector, is termed epidemic strains. The other type does not typically cause human infections by normal routes of infection, but is virulent for rodents and is termed endemic strains. Previous classification schemes used outside the Western hemisphere referred to these latter strains as Pestoides varieties of Y. pestis. Recent molecular analysis has definitely shown that both endemic and epidemic strains arose independently from a common Yersinia pseudotuberculosis ancestor. Currently, 11 major groups of Y. pestis are defined globally.
Use of a Hydrolytic Procedure and Spectrometric Methods in the Structure Elucidation of a Thiocarbonyl Analogue of Sildenafil Detected as an Adulterant in an Over-the-Counter Herbal Aphrodisiac
Authors: Reepmeyer John C , d'Avignon D Andr
Published: February 2020

A sildenafil-related compound was detected in an herbal dietary supplement marketed as an aphrodisiac. The compound was identified as an analogue of sildenafil in which the carbonyl group in the pyrimidine ring of sildenafil was substituted with a thiocarbonyl group, and the methyl group on the piperazine ring was substituted with a hydroxyethyl group. Based on this structure, the compound was named thiohydroxyhomosildenafil. The structure of the compound was established using HPLC/MS, UV spectrometry, electrospray ionization-MS/MS, NMR spectrometry, and a hydrolytic process. One key product of hydrolysis was 1-(2-hydroxyethyl)-piperazine; the identification of this product defined the amine portion of the compound. Another key product of hydrolysis was hydroxyhomosildenafil, generated by hydrolysis of the thiocarbonyl group to a carbonyl group (C S C O). Hydroxyhomosildenafil was detected as a minor component in the dietary supplement.
Comparative Validation Study to Demonstrate the Equivalence of a Minor Modification to AOAC Method 997.03 Visual Immunoprecipitate (VIP®) for Listeria to the Reference Culture Method
Authors: Feldsine Philip T , Kerr David E , Shen George , Lienau Andrew H
Published: February 2020

The Visual Immunoprecipitate (VIP®) for the Detection of Listeria in Foods and Environmental Surfaces, AOAC Official Method 997.03, has been modified to change the color of the test and control lines of the device. A methods comparison study was conducted to demonstrate the equivalence of this modification to the reference culture method. Two food matrixes and one environmental surface were analyzed. In total, there were valid results from 100 samples and controls. Results showed that the modified VIP Gold® for Listeria spp. is equivalent to the reference culture methods for the detection of Listeria.
Comparative Validation Study to Demonstrate the Equivalence of a Minor Modification to AOAC Method 999.09 Visual Immunoprecipitate (VIP®) for Salmonella Method to the Reference Culture Method
Authors: Feldsine Philip T , Kerr David E , Shen George , Lienau Andrew H
Published: February 2020

The Visual Immunoprecipitate (VIP®) for the Detection of Salmonella in Foods, AOAC Official Method 999.09, has been modified to change the color of the test and control lines of the device. A methods comparison study was conducted to demonstrate the equivalence of this modification to the reference culture method. Three foods were analyzed. In total, there were valid results from 155 samples and controls. Results showed that the modified VIP Gold® for Salmonella is equivalent to the reference culture methods for the detection of Salmonella.
Improving the AOAC Use-Dilution Method by Establishing a Minimum Log Density Value for Test Microbes on Inoculated Carriers
Authors: Tomasino Stephen F , Pines Rebecca M , Hamilton Martin A
Published: February 2020

The AOAC Use-Dilution methods, 955.14 (Salmonella enterica), 955.15 (Staphylococcus aureus), and 964.02 (Pseudomonas aeruginosa), are used to measure the efficacy of disinfectants on hard inanimate surfaces. The methods do not provide procedures to assess log density of the test microbe on inoculated penicylinders (carrier counts). Without a method to measure and monitor carrier counts, the associated efficacy data may not be reliable and repeatable. This report provides a standardized procedure to address this method deficiency. Based on carrier count data collected by four laboratories over an 8 year period, a minimum log density value is proposed to qualify the test results. Carrier count data were collected concurrently with 242 Use-Dilution tests. The tests were conducted on products bearing claims against P. aeruginosa and S. aureus with and without an organic soil load (OSL) added to the inoculum (as specified on the product label claim). Six carriers were assayed per test for a total of 1452 carriers. All 242 mean log densities were at least 6.0 (geometric mean of 1.0 106 CFU/carrier). The mean log densities did not exceed 7.5 (geometric mean of 3.2 107 CFU/carrier). For all microbes and OSL treatments, the mean log density (SEM) was 6.7 (0.07) per carrier (a geometric mean of 5.39 106 CFU/carrier). The mean log density for six carriers per test showed good repeatability (0.29) and reproducibility (0.32). A minimum mean log density of 6.0 is proposed as a validity requirement for S. aureus and P. aeruginosa. The minimum level provides for the potential inherent variability that may be experienced by a wide range of laboratories and the slight effect due to the addition of an OSL. A follow-up report is planned to present data to support the carrier count procedure and carrier counts for S. enterica.
Determination of Trace Amounts of Lead and Manganese in Water Samples After Simultaneous Preconcentration onto Modified Amberlite XAD-4 Resin
Authors: Mobarakeh Sayed Zia Mohammadi , Afzali Darush , Taher Mohammad Ali , Dargahi Roza
Published: February 2020

A procedure for simultaneous separation and preconcentration of trace amounts of manganese and lead has been proposed. It is based on the adsorption of manganese and lead ions onto a column of Amberlite XAD-4 resin loaded with pyrocatechol reagent. Manganese and lead were quantitatively retained on the column in the pH range 4.06.5 at a flow rate of 2 mL/min. The manganese and lead ions were eluted with 5.0 mL of 4 M HNO3 solutions. Manganese and lead were measured by flame atomic absorption spectrometry. In this case, 100.0 ng manganese and 1000.0 ng lead were concentrated in the column from 800 mL of aqueous sample, where their concentrations were as low as 0.125 and 1.25 ng/mL, respectively. Seven replicate determinations of mixtures of 1.0 g/mL manganese and 2.0 g/mL lead in the final solution gave a mean absorbance of 0.1926 and 0.0832 with RSD values of 1.1 and 1.2, respectively. The LODs were 1.76 ng/mL for Mn(II) and 37.28 ng/mL for Pb(II) (3bl/m) in the final solution, with a preconcentration factor of 160. Sensitivities for 1 absorbance for Mn(II) and Pb(II) were 7.0 and 74.7 ng/mL, respectively. The interference of a large number of anions and cations has been studied and the optimized conditions were used for determination of trace amounts of manganese and lead in various environmental and standard samples.
Determination of Atropine Enantiomers in Ophthalmic Solutions by Liquid Chromatography Using a Chiral AGP Column
Authors: Soares Renata , Singh Anil Kumar , Kedor-Hackmann Erika Rosa Maria , Santoro Maria Inês Rocha Miritello
Published: February 2020

Many therapeutic agents are commercialized under their racemic form. The enantiomers can show differences in the pharmacokinetic and pharmacodynamic profile. The use of a pure enantiomer in pharmaceutical formulations may result in a better therapeutic index and fewer adverse effects. Atropine, an alkaloid of Atropa belladonna, is a racemic mixture of l-hyoscyamine and d-hyoscyamine. It is widely used to dilate the pupil. To quantify these enantiomers in ophthalmic solutions, an HPLC method was developed and validated using a Chiral AGP column at 20C. The mobile phase consisted of a buffered phosphate solution (containing 10 mM 1-octanesulfonic acid sodium salt and 7.5 mM triethylamine, adjusted to pH 7.0 with orthophosphoric acid) and acetonitrile (99 + 1, v/v). The flow rate was 0.6 mL/min, with UV detection at 205 nm. In the concentration range of 14.026.0 g/mL, the method was found to be linear (r > 0.9999), accurate (with recovery of 100.1100.5), and precise (RSD system 0.6; RSD intraday 1.1; RSD interday 0.9). The method was specific, and the standard and sample solutions were stable for up to 72 h. The factorial design assures robustness with a variation of 10 in the mobile phase components and 2C of column temperature. The complete validation, including stress testing and factorial design, was studied and is presented in this research.
Analysis of Photochemically Induced Cotton Bound Residues of Deltamethrin by an Immunoassay Technique
Authors: Soltan Hamdy R , Abd El-Megeed Fawkia A , Mustafa Fathia I , Ismail Hanafy M
Published: February 2020

A sensitive and selective indirect competitive ELISA was developed for the detection of deltamethrin bound residues on cotton texture. Cross-reactivity studies with the main deltamethrin photodegradation products showed high specificity of deltamethrin polyclonal antibody to the parent compound. No cross-reactivity was measured with deltamethrin photodegradtion products derived from the alcohol moiety (3-phenoxybenzaldhyde, phenoxybenzyl alcohol, cyanohydrin, and 3-phenoxybenzoic acid), and lesser amounts were observed with the acid moiety (deltamethric acid). The dot-blot immunoassay was performed on cotton fabric discs spiked with deltamethrin and irradiated to assess the suitability of this system to detect bound residue. The dot-blot immunoassay results revealed that the bound form of deltamethrin has binding affinity with deltamethrin antibody similar to the parent compound. In addition, the test system was used to detect bound and free residues of deltamethrin on cotton samples exposed to three cycles of simulated sunlight and water wash. The results obtained suggest that the competitive ELISA format can be used as a tool for monitoring free and bound residues of deltamethrin impregnated on cotton targets.
Singlepath Salmonella
Authors: Lindhardt Charlotte , Schönenbrücher Holger , Slaghuis Jörg , Bubert Andreas , Ossmer Rolf , Hammack Thomas
Published: February 2020

Singlepath Salmonella is an immunochromatographic (lateral flow) assay for the presumptive qualitative detection of Salmonella spp. in food. A previous AOAC Performance Tested MethodSM study evaluated Singlepath Salmonella as an effective method for the detection of Salmonella spp. in the following selected foods: dried skimmed milk, black pepper, dried pet food, desiccated coconut, cooked peeled frozen prawns, raw ground beef, and raw ground turkey. In this Emergency Response Validation extension, creamy peanut butter was inoculated with S. enterica. ser. Typhimurium. For low contamination level (1.08 CFU/25 g), a Chi-square value of 0.5 indicated that there was no significant difference between Singlepath Salmonella and the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) reference method. For high-level and uninoculated control there was 100 agreement between the methods.
CHROMagar Salmonella Detection Test Kit
Authors: Webb Katana , Ritter Vicki , Hammack Thomas
Published: February 2020

BBL CHROMagar Salmonella was evaluated by an external food testing laboratory for the recovery of Salmonella in peanut butter using the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) procedure. The peanut butter was found to be negative for the presence of Salmonella and, therefore, was seeded with heat-stressed Salmonella at target concentrations of 0.2 and 2 CFU/25 g. The Salmonella-seeded samples remained at room temperature for 14 days before analysis to stabilize the Salmonella in the food environment. Twenty 25 g test portions from each seeded level and five 25 g samples of uninoculated control samples were processed using enrichment broths as outlined in the FDA-BAM procedure. BBL CHROMagar Salmonella-prepared plates were evaluated with the FDA reference method media (bismuth sulfite, xylose lysine desoxycholate, and Hektoen enteric agars). Fractionally positive results were obtained from the lower inoculum level of peanut butter samples. Five positive cultures were recovered from both the BBL CHROMagar Salmonella and reference methods. The two methods gave identical results for all cultures resulting in a method agreement of 100%. McNemar's 2 test, which assesses the evidence for difference in marginal proportions between two methods, could not be evaluated because it requires one or more discrepant cultures. However, because there were no discrepant cultures, the marginal proportions for the two methods were identical; therefore, there is no evidence of a difference between the methods. This study demonstrates that the results from BBL CHROMagar Salmonella are comparable to the three reference method media for the detection of Salmonella in peanut butter using the FDA-BAM procedures.
A Novel Real-Time Polymerase Chain Reaction Method for the Detection of Brazil Nuts in Food
Authors: Brežná Barbara , Dudášová Hana , Kuchta Tomáš
Published: February 2020

A qualitative real-time PCR-based method for the detection of the Brazil nut (Bertholletia excelsa) component in food is described. The method consists of DNA isolation by chaotropic SPE and the subsequent PCR with Brazil nut-specific primers and a TaqMan fluorescent probe. The primers and the probe are targeted to the gene encoding for the 11s globulin of the Brazil nut. The method was positive for eight Brazil nut samples from the market and negative for all other tested plant and meat materials used in the food industry (36 samples). The intrinsic LOD of the method was 10 pg Brazil nut DNA. Using a series of model nut paste mixtures with defined Brazil nut contents, a practical detection limit of 0.1 (w/w) Brazil nut was estimated. Practical applicability of the entire method was tested by qualitative analysis of nine food samples; no discrepancies between the declared and detected Brazil nut contents were found. The presented PCR-based method is useful for sensitive and selective detection of Brazil nut in food samples.
Evaluation of the MIT RMID 1000 System for the Identification of Listeria Species
Authors: Ricardi John , Haavig David , Cruz Lasaunta , Paoli George , Gehring Andrew
Published: February 2020

The Micro Imaging Technology (MIT) 1000 Rapid Microbial Identification (RMID) System is a device that uses the principles of light scattering coupled with proprietary algorithms to identify bacteria after being cultured and placed in a vial of filtered water. This specific method is for pure culture identification of Listeria spp. A total of 81 microorganisms (55 isolates) were tested by the MIT 1000 System, of which 25 were Listeria spp. and 30 a variety of other bacterial species. In addition, a total of 406 tests over seven different ruggedness parameters were tested by the MIT 1000 System to determine its flexibility to the specifications stated in the MIT 1000 System User Guide in areas where they might be deviated by a user to shorten the test cycle. Overall, MIT concluded that the MIT 1000 System had an accuracy performance that should certify this Performance Test Method for the identification of Listeria spp. This report discusses the tests performed, results achieved, and conclusions, along with several reference documents to enable a higher understanding of the technology used by the MIT 1000 System.
Electrospray Ionization Matrix Effect as an Uncertainty Source in HPLC/ESI-MS Pesticide Residue Analysis
Authors: Kruve Anneli , Herodes Koit , Leito Ivo
Published: February 2020

The matrix effects in HPLC/electrospray ionization (ESI)-MS analysis are difficult to compensate for because of their large variability. It is, therefore, often more practical to include uncertainty due to the matrix effect into the uncertainty budget rather than try to compensate. This work presents an empirical approachthe matrix effect graph approachfor estimating the uncertainty due to the matrix effect in HPLC/ESI-MS analysis of pesticide residues in fruits and vegetables. At certain time intervals (1 month), a calibration graph using extracts of different fruits/vegetables as calibration solutions is prepared, and a regression line is fitted through these data. These fruits/vegetables may be either from the commodity group of the samples or from different commodity groups. The relative residuals of the calibration point peak areas are calculated and plotted against the measurement time. We term the resulting graph the matrix effect graph. The root mean square of the relative residuals is calculated and used as the estimate of relative uncertainty of the sample peak areas caused by the matrix effect. The matrix effect graph obtained over fruits/vegetables from different commodity groups can also be used to identify fruits/vegetables with extreme matrix effects. The matrix effect graph approach was used for determination of thiabendazole, aldicarb, imazalil, and methiocarb and was validated with tomato, cucumber, and sweet corn matrixes at the 0.5 mg/kg concentration level. When different commodity groups were used to compile the matrix effect graph, results of analysis of all samples agreed with the spiked concentrations within the expanded uncertainties (at k = 2 level). When the matrix effect graph was compiled using fruits from the same commodity group as the analyzed samples (fruiting vegetables in this case), agreement was found in 98 of the cases.
Development of a Gas Chromatographic/Mass Spectrometric Method for Determination of Phthalates in Oily Foods
Authors: Sannino Anna
Published: February 2020

A GC/MS method was developed for simultaneous determination of 12 phthalates and four other plasticizersacetyl tributyl citrate, di(2-ethylhexyl) adipate, dibutyl sebacate, di-isononyl cyclohexane 1,2-dicarboxylate (DINCH)in vegetable oil, pesto, and tomato sauce. Samples were extracted with acetonitrile and cleaned on a Florisil column. The final extract was analyzed by GC in combination with ion trap MS. The phthalates and di-isononyl cyclohexane 1,2-dicarboxylate were detected by MS/MS, while the other three plasticizers were monitored in the same GC run using full scan mode. The analytical process was validated in each matrix by the analysis of blank samples. Performance characteristics, such as linearity, LOQ, precision, and recoveries were studied. Studies at fortification levels of 0.25200 mg/kg gave mean recoveries ranging from 71 to 106 and RSD values between 7 and 12 for all compounds. LOQs were 0.0500.10 mg/kg for all the target compounds except di-isononyl phthalate, di-isodecyl phthalate, and DINCH (2.0 mg/kg).
Determination of Lycopene in Dietary Supplements and Raw Materials by High-Performance Liquid Chromatography: Collaborative Study
Authors: Waysek Edward H , Schierle Joseph , Duesterloh Andre , Deshpande Jayant , Austad John ,   Collaborators:, Austad J , Blatt Y , Chan Y F , Deshpande J , Duesterloh A , Kumar T K S , LaLuzerne P , Nemzer B , Ortiz J F L , Peadon P , Reif K , Schierle J , Stanley S , Tang C Y
Published: February 2020

A collaborative study was conducted to evaluate the interlaboratory performance of an LC method for lycopene in dietary supplements and the raw materials commonly used in their manufacture. Twelve laboratories from six countries agreed to participate in the study. Results from 10 laboratories were received and are reported. Five dietary supplements, including both tablets and a softgel capsule with a lycopene content ranging from 25 g to 25 mg per unit, and three raw materials, including gelatin-based beadlets, vegetarian beadlets, and a suspension in oil ranging from 5 to 20 lycopene, were analyzed as blind duplicates. In addition to the commercial products, two positive controls and a negative control were included in the study. For the raw materials studied, the repeatability relative standard deviations (RSDr) ranged from 1.49 to 5.13 for total lycopene, and the reproducibility relative standard deviations (RSDR) ranged from 3.84 to 9.21 with HorRat values from 1.23 to 3.24. For finished products, the RSDr ranged from 1.31 to 4.62, RSDR from 4.28 to 10.5, and HorRat values from 0.79 to 2.07. Corresponding values for all-trans-lycopene were significantly higher. It is recommended that the method be considered for Official First Action for all-trans- and total lycopene in finished products and raw materials.
Detection of Staphylococcal Enterotoxin B in Milk and Milk Products Using Immunodiagnostic Lateral Flow Devices
Authors: Boyle Thomas , Njoroge Joyce M , Jones Robert L , Principato Maryann
Published: February 2020

Staphylococcal enterotoxin B (SEB) is an extracellular pyrotoxin produced by Staphylococcus aureus, a known etiologic agent of food poisoning in humans. Lateral flow immunochromatographic devices (LFDs) designed for the environmental detection of SEB were adapted for use in this study to detect SEB in milk containing 2 fat, chocolate-flavored milk, and milk-derived products such as yogurt, infant formula, and ice cream. The advantage of using LFDs in these particular food products was its ease and speed of use with no additional extraction methods needed. No false positives were observed with any of the products used in this study. Dilution of the samples overcame the Hook effect and permitted capillary flow into the membrane. Thus, semisolid products such as ice cream and some yogurts, and products containing thickeners needed to be diluted using a phosphate-buffered saline-based buffer, pH 7.2. SEB was easily detected at concentrations of 5 g/mL and 500 ng/mL when the LFDs were used. SEB was also reliably detected at concentrations below 5 and 0.25 ng/mL, which may induce serious disease.
Establishment and In-House Validation of Simplex and Duplex PCR Methods for Event-Specific Detection of Maize SYN-E3272-5 Using a New Reference Molecule
Authors: Shen Kailin , Li Xiang , Wang Shu , Pan Yingjie , Shi Zhiyi , Sun Yongning , Yang Litao
Published: February 2020

Despite rapid developments in the detection techniques for genetically modified organisms (GMOs), the event-specific PCR method with high specificity is still the most used technique. In this study, event-specific simplex and duplex qualitative and quantitative detection systems were developed targeting the 3 insertion site of GM maize SYN-E3272-5 (3272) construct. A reference molecule p3272 was constructed to act as positive control and as calibrator for quantitative analysis. The LOD for simplex and duplex qualitative PCR assays was 10 copies of p3272 control DNA. LOD and the LOQ for simplex and duplex quantitative PCR assays were 10 and 25 copies of p3272 DNA, respectively. Furthermore, four practical GM maize samples were quantified using the established simplex and duplex quantitative PCR systems by in-house validation. Results from five operators showed that the bias ranged from 3.44 to 17.24 in the simplex system and from 0.42 to 16.06 in the duplex system, respectively. These results demonstrated that the established event-specific simplex and duplex qualitative and quantitative PCR systems combined with the reference molecule p3272 are suitable for the detection of GM maize 3272 and its derived products.
Effect of Radiation Sterilization on Alprenolol in the Solid State Studied by High-Performance Thin-Layer Chromatography
Authors: Marciniec Barbara , Ogrodowczyk Magdalena , Kwiecien′ Anna
Published: February 2020

The possibility of radiation sterilization of alprenolol (AL) has been studied. Irradiation of AL in solid form with a 25 kGy beam of electrons caused only an insignificant change in color that became more intense with increasing irradiation dose. Moreover, with increasing dose a decrease in pH, the content of water, and the degree of crystallinity were observed. AL in solid form was radiated with a high-energy electron beam (9.96 MeV) at doses from 25400 kGy and analyzed by HPTLC using the mobile phase methanolammonia 25 (99 + 1, v/v). Densitometric analysis was carried out directly from chromatograms at 270 nm. The applied method was validated and characterized by good precision (RSD = 3.95); good accuracy (80 level 100.15, 100 level 99.99, and 120 level 104.44); and low LOD (LOD = 0.52 g/zone and LOQ = 1.55 g/zone). Chromatograms recorded for samples irradiated at the doses of 25 kGy were unchanged, but at higher doses (100400 kGy) additional peaks corresponding to the radiodegradation products appeared (Rf = 0.24 and Rf = 0.40). The decrease in the concentration of AL was proportional to the applied radiation dose, and for 400 kGy the concentration of AL was 90.23. The calculated radiolytic yield of the radiodegradation process was G(AL) = 7.12 107 mol/J.
Development and Validation of Spectrophotometric and High-Performance Column Liquid Chromatographic Methods for the Simultaneous Determination of Dienogest and Estradiol Valerate in Pharmaceutical Preparations
Authors: Çağlayan Mehmet Gökhan , Palabiyik Ismail Murat , Onur Feyyaz
Published: February 2020

Simultaneous determination of dienogest (DIE) and estradiol valerate (EST) in sugar-coated tablets was performed by using HPLC and spectrophotometry. In HPLC, the separation was achieved on an ACE C8 column using the mobile phase acetonitrileNH4NO3 (0.03 M, pH 5.4; 70 + 30, v/v) at a flow rate of 2 mL/min. The detection wavelength was 280 nm, and cyproterone acetate was selected as an internal standard. The linearity range was 3.045.0 g/mL for DIE and 18.0100.0 g/mL for EST. As spectrophotometric methods, two chemometric methods, principal component regression and partial least-squares, were developed. In the chemometric techniques, the concentration data matrix was prepared by using mixtures containing these drugs in methanolwater (3 + 1, v/v). The absorbance data matrix corresponding to the concentration data matrix in these methods was obtained by the measurement of absorbances in their zero-order spectra; then, the calibration was obtained by using the data matrix for the prediction of unknown concentrations of DIE and EST in their binary mixture. Working ranges were found as 2.024.0 g/mL for DIE and 20.0270.0 g/mL EST in the methods. These three developed methods were validated and successfully applied to a pharmaceutical preparation, a sugar-coated tablet, and the results were compared with each other.
Rapid HPLC Determination of Pioglitazone in Human Plasma by Protein Precipitation and Its Application to Pharmacokinetic Studies
Authors: Islambulchilar Ziba , Valizadeh Hadi , Zakeri-Milani Parvin
Published: February 2020

A simple and rapid HPLC method with UV detection was developed for the determination of pioglitazone in human plasma. The method was based on protein precipitation using perchloric acid on an ODS column. The mobile phase consisted of a mixture of phosphate buffer, methanol, acetonitrile, and 12 M perchloric acid (54 + 33 + 12 + 1, v/v/v/v). The UV detector was set at 269 nm. Under these conditions, the retention time of pioglitazone was 5.2 min. The standard curve was linear over the range of 502000 ng/mL pioglitazone in human plasma. The within-day and between-day precision studies showed high reproducibility, with CV less than 5. The LOQ was 44.2 ng/mL. The method has been applied to a bioequivalence study after administration of pioglitazone as 30 mg tablets to 12 healthy volunteers.
Development of a Size-Exclusion HPLC Method with Evaporative Light-Scattering Detection for the Quantitation of Polysorbate 80 in Houttuynia cordata Injection
Authors: Wu Yi , Li Xiao D , Lin Rui C , Jin Shao H
Published: February 2020

A rapid and accurate size-exclusion HPLC method for the quantitation of polysorbate 80 (PS80) in Houttuynia cordata injection, a Chinese traditional medicine, was developed and validated. The assay was conducted on an Agilent 1100 HPLC system with a TosoHaas TSKgel G2000 SWXL column (30 cm 7.8 mm, 5 m particle size) and an Alltech evaporative light-scattering detector (ELSD) 2000. The mobile phase was 20 mmoL/L ammonium acetateacetonitrile (90 + 10, v/v) delivered at a flow rate of 0.6 mL/min under isocratic conditions. The ELSD was operated in the impactor off mode, the drift tube temperature was set at 110C, and nitrogen flow was maintained at 2.3 L/min. The LOD was 0.25 mg/mL. Linearity was obtained between the log of concentration (C) and the log of peak area (Y) of PS80 in the range of 0.520 mg/mL according to the equation: Log Y = 1.4529 Log C 0.8232 (r2 = 0.9976). An RSD of 1.6 (n = 6) for the determination demonstrated the good precision of the optimized method. PS80 content in several commercial H. cordata injection products from different manufacturers was determined. The data for PS80 content is useful in evaluation of the safety of the products from different manufacturers.
Evaluation of DuPont Qualicon BAX System PCR Assay for Yeast and Mold
Authors: Wallace F Morgan , Burns Frank , Fleck Lois , Andaloro Bridget , Farnum Andrew , Tice George , Ruebl Joanne
Published: February 2020

Evaluations were conducted to test the performance of the BAX System PCR assay which was certified as Performance Tested MethodSM 010902 for screening yeast and mold in yogurt, corn starch, and milk-based powdered infant formula. Method comparison studies performed on samples with low-level inoculates showed that the BAX System demonstrates a sensitivity equivalent to the U.S. Food and Drug Administration's Bacteriological Analytical Manual culture method, but with a significantly shorter time to obtain results. Tests to evaluate inclusivity and exclusivity returned no false-negative and no false-positive results on a diverse panel of isolates, and tests for lot-to-lot variability and tablet stability demonstrated consistent performance. Ruggedness studies determined that none of the factors examined affected the performance of the assay.