bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative Determination of Flavonoids by Column High-Performance Liquid Chromatography with Mass Spectrometry and Ultraviolet Absorption Detection in Artemisia afra and Comparative Studies with Various Species of Artemisia Plants
Authors: Avula Bharathi , Wang Yan-Hong , Smillie Troy J , Mabusela Wilfred , Vincent Leszek , Weitz Frans , Khan Ikhlas A
Published: February 2020

A simple and specific analytical method for the quantitative determination of flavonoids from the aerial parts of the Artemisia afra plant samples was developed. By column high-performance liquid chromatography (HPLC) with UV absorption and mass spectrometry (MS) detection, separation was achieved on a reversed-phase octadecylsilyl (C18) column with water, methanol, and acetonitrile, all containing 0.1 acetic acid, as the mobile phase. These methods were used to analyze various species of Artemisia plant samples. The wavelength used for quantification of flavonoids with the diode array detector was 335 nm. The limits of detection (LOD) by HPLC/MS were found to be 7.5, 7.5, 10, 2.0, and 2.0 ng/mL; and by LC-UV the LODs were 500, 500, 500, 300, and 300 ng/mL for apigenin, chrysoeriol, tamarixetin, acacetin, and genkwanin, respectively. The HPLC/MS method was found to be 50150 times more sensitive than the HPLC-UV method. HPLC/MS coupled with an electrospray ionization interface is described for the identification and quantification of flavonoids in various plant samples. This method involved the use of the MH ions of the compounds at mass-to-charge ratio of 1.0606, 301.0712, 317.0661, 285.0763, and 285.0763 (calculated mass), respectively, in the positive ion mode with extractive ion monitoring.
Rapid and Cost-Effective Determination of Acrylamide in Coffee by Planar Chromatography and Fluorescence Detection After Derivatization with Dansulfinic Acid
Authors: Alpmann Alexander , Morlock Gertrud
Published: February 2020

A new method has been developed for the determination of acrylamide in ground coffee by planar chromatography using prechromatographic in situ derivatization with dansulfinic acid. After pressurized fluid extraction of acrylamide from the coffee samples, the extracts were passed through activated carbon and concentrated. These extracts were applied onto a silica gel 60 HPTLC plate and oversprayed with dansulfinic acid. By heating the plate, acrylamide was derivatized into the fluorescent product dansylpropanamide. The chromatographic separation with ethyl acetatetert.-butyl methyl ether (8 + 2, v/v) mobile phase was followed by densitometric quantification at 254/>400 nm using a 4 point calibration via the standard addition method over the whole system for which acrylamide was added at different concentrations at the beginning of the extraction process. The method was validated for commercial coffee. The linearity over the whole procedure showed determination coefficients between 0.9995 and 0.9825 (n = 6). Limit of quantitation at a signal-to-noise ratio of 10 was determined to be 48 g/kg. The within-run precision (relative standard deviation, n = 6) of the chromatographic method was 3. Commercial coffee samples analyzed showed acrylamide contents between 52 and 191 g/kg, which was in correlation with amounts reported in previous publications.
Multiplex Polymerase Chain Reaction-Capillary Gel Electrophoresis: A Promising Tool for GMO ScreeningAssay for Simultaneous Detection of Five Genetically Modified Cotton Events and Species
Authors: Nadal Anna , Esteve Teresa , Pla Maria
Published: February 2020

A multiplex polymerase chain reaction assay coupled to capillary gel electrophoresis for amplicon identification by size and color (multiplex PCR-CGE-SC) was developed for simultaneous detection of cotton species and 5 events of genetically modified (GM) cotton. Validated real-time-PCR reactions targeting Bollgard, Bollgard II, Roundup Ready, 3006-210-23, and 281-24-236 junction sequences, and the cotton reference gene acp1 were adapted to detect more than half of the European Union-approved individual or stacked GM cotton events in one reaction. The assay was fully specific (<1.7 of false classification rate), with limit of detection values of 0.1 for each event, which were also achieved with simulated mixtures at different relative percentages of targets. The assay was further combined with a second multiplex PCR-CGE-SC assay to allow simultaneous detection of 6 cotton and 5 maize targets (two endogenous genes and 9 GM events) in two multiplex PCRs and a single CGE, making the approach more economic. Besides allowing simultaneous detection of many targets with adequate specificity and sensitivity, the multiplex PCR-CGE-SC approach has high throughput and automation capabilities, while keeping a very simple protocol, e.g., amplification and labeling in one step. Thus, it is an easy and inexpensive tool for initial screening, to be complemented with quantitative assays if necessary.
Liquid Chromatographic Determination of Narirutin and Hesperidin in Zhi Ke (Citrus aurantium L.) in the Form of the Raw Herb and of the Dried Aqueous Extract
Authors: Lee Samiuela , Khoo Cheang S , Pearson Jarryd L , Hennell James R , Bensoussan Alan
Published: February 2020

A validated analytical method is reported for the analysis of narirutin and hesperidin in Zhi Ke (Citrus aurantium L.) in the form of the dried raw herb and of the commercially prepared dried aqueous extract. The samples were extracted by sonication in methanol and the extract was analyzed by liquid chromatography-photodiode array (PDA) detection with identity confirmation by negative electrospray ionization-tandem mass spectrometry (MS). A C18 column was used with a methanolwater gradient mobile phase. Narirutin and hesperidin were quantified at 284 nm using the PDA detector. Using the MS detector, the narirutin precursor ion with m/z 579 produced daughter ions with m/z 271 and 151. For hesperidin, the precursor ion with m/z 609 produced the m/z 301, 285, and 164 ions. The amounts of narirutin and hesperidin found in the certified raw herb were 14.2 and 147.9 mg/g, respectively, and in the dried aqueous extract the amounts were 9.2 and 8.6 mg/g, respectively. For the raw herb, the average recovery across the three spike levels (50, 100, and 150) for narirutin and hesperidin were 110.7 and 94.5, respectively. For the dried aqueous extract, the average recovery across the three spike levels for narirutin and hesperidin were 85.8 and 98.9, respectively.
Separation and Determination of Clenbuterol by HPLC Using a Vancomycin Chiral Stationary Phase
Authors: Mostafa Gamal A E , Hefnawy Mohammed M , El-Majed Abdulrahman
Published: February 2020

Enantiomers of clenbuterol were separated by a new HPLC method on a chiral column. Enantiomeric resolution was achieved on a vancomycyin macrocyclic antibiotic chiral stationary phase known as chirobiotic V with UV detection at 247 nm. The polar ionic mobile phase consisting of methanoltriethylamineglacial acetic acid (100 + 0.05 + 0.025, v/v/v), was used at a flow rate of 1.0 mL/min. The method was validated for linearity, accuracy, precision, and robustness. Standard linear calibration curves were established for the R-() and S-(+) enantiomers over the range of 0.220 g/mL, and an average recovery of 98.0 and a mean relative standard deviation of 1.5 were obtained at 5.0 g/mL. The lower limit of detection was 0.05 g/mL for each enantiomer. The mean recovery for R-() and S-(+)-clenbuterol enantiomers from plasma was 91.097.0 at 0.2020 g/mL. The method was successfully used to identify and quantify the clenbuterol enantiomers in human plasma.
The Glycemic Index: Methodological Aspects Related to the Interpretation of Health Effects and to Regulatory Labeling
Authors: Aziz Alfred
Published: February 2020

The glycemic index (GI) is an experimental system that classifies carbohydrates (CHO) and CHO-containing foods according to their blood glucose-raising potential. It is based on the glycemic response following the ingestion of a test food containing a defined amount of available CHO relative to that of an equi-carbohydrate portion of either white bread or glucose. The concept has been extended to mixed meals and whole diets where the GI of the meal/diet is expressed as the weighted average of the GI of each food, based on the percentage of the total meal/diet CHO provided by each food. Over the last few decades, a substantial number of epidemiological and interventional studies have reported beneficial associations/effects of lower GI diets across a wide spectrum of pathophysiological conditions, including diabetes, cardiovascular disease, obesity, and certain forms of cancer. This has prompted proponents of the GI to recommend its use for dietary planning and labeling purposes. However, the currently recommended GI methodology is not well standardized and has several flaws, which brings into question the strength of evidence attributed to the health effects of low-GI diets. This review focuses exclusively on the methodological aspects of the GI, how they might impact the interpretation of data related to the purported health benefits of low GI diets, and the considerations for the use of the GI in food labeling. In addition, alternative systems for classifying the glycemic effects of CHO-containing foods are briefly discussed.
GC/MS Screening Method for Phthalate Esters in Children's Toys
Authors: Ting Keh-Chuh , Gill Modan , Garbin Orlando
Published: February 2020

Phthalate esters are commonly added into polyvinyl chloride (PVC) as softeners to make the plastic material flexible. Phthalates are suspected cancer-causing agents and possible teratogens; they have been linked to liver and kidney damage, as well as the underdevelopment of reproductive organs in humans and animals. Public safety concerns about human exposure to phthalates are on the rise because they do not chemically bond to PVC and leach from the material over time. Following the lead of the European Union and Japan in restricting the use of certain phthalates, a legal limit of 0.1 in children's toys was established by the California State Legislature (AB-1108). In addition to its mission to protect public health and the environment from toxic harm, the California Department of Toxic Substances Control (DTSC) has been delegated the role of lead agency for consumer product safety. To support DTSC's Green Chemistry activities, the Environmental Chemistry Laboratory Mobile Laboratory Team has developed an on-site screening method to monitor phthalates in children's toys. This method is simple, fast, and effective, with ample sensitivity to quantify the 6 restricted phthalates in children's toys at 100 ppm (limit of quantitation = 100 g/g) which is 10 times lower than the legal allowable level of 0.1. Additionally, the method has a high throughput capability and enables testing of approximately 610 samples per day, depending on the complexity of the sample matrix and concentration. This method is designed to survey the 6 phthalates in children's toys and other consumer products for compliance with the threshold of 0.1 (1000 ppm).
Simultaneous Determination of Florfenicol and Its Metabolite Florfenicol Amine in Swine Muscle Tissue by a Heterologous Enzyme-Linked Immunosorbent Assay
Authors: Luo Pengjie , Jiang Haiyang , Wang Zhanhui , Feng Caimao , He Fangyang , Shen Jianzhong
Published: February 2020

A sensitive and heterologous enzyme-linked immunosorbent assay (ELISA) for the simultaneous detection of florfenicol (FF) and its metabolite florfenicol amine (FFA) in swine muscle tissue was developed. FFA was conjugated to bovine serum albumin by a formaldehyde coupling method as an immunogen to immunize rabbits. FFA, thiamphenicol glycinate, and modified FF were conjugated to ovalbumin as coating antigens. The effect of different types of hapten heterology on the sensitivity and specificity of the ELISA was evaluated. Using FF glutaric anhydride ester as a coating hapten and antibody raised against modified FFA, an ELISA was developed that showed an IC50 value of 0.48 ng/mL. The antibody showed a cross-reactivity of 100 with FFA, 97 with FF, 6 with thiamphenicol, and a negligible value with chloramphenicol. From fortified swine muscle samples at levels of 4320 ng/g, the average recoveries of FF and FFA ranged from 58.2 to 96.8, with coefficients of variation less than 14. Analysis of incurred samples by the ELISA gave similar results to those by a previously developed liquid chromatographic method. The ELISA could be used as a rapid method for the simultaneous determination of FF and FFA in swine muscle tissue.
Validated High-Throughput HPLC Method for the Analysis of Flavonol Aglycones Myricetin, Quercetin, and Kaempferol in Rhus coriaria L. Using a Monolithic Column
Authors: Mehrdad Morteza , Zebardast Mahnoosh , Abedi Ghazaleh , Koupaei Mitra Nouri , Rasouli Hoda , Talebi Mohammad
Published: February 2020

A rapid and simple reversed-phase high-performance liquid chromatographic method using a monolithic column was developed and validated for the separation and quantification of myricetin, quercetin, and kaempferol in Rhus coriaria L. The method employed the isocratic mobile phase acetonitrile10 mM potassium dihydrogen orthophosphate buffer adjusted to pH 3.0 using orthophosphoric acid (38 + 62, v/v) at a flow rate of 4.0 mL/min; a Chromolith Performance RP-18e (100 4.6 mm) monolithic column kept at 40C; and UV detection at 370 nm. Although the elution order was identical and the selectivity was equivalent, the comparison between monolithic and particulate columns showed that the monolithic column could reduce the separation time to <1 min without sacrificing column efficiency and selectivity. The method was validated according to International Conference on Harmonization guidelines. The validation characteristics included accuracy, precision, linearity, range, specificity, LOQ, and robustness. The calibration curves were linear (r >0.999) over the concentration range of 0.8888.3 g/mL for myricetin, 0.9595 g/mL for quercetin, and 1.43143.3 g/mL for kaempferol. The recoveries for all three compounds were above 89. Myricetin was found to be the major flavonol in the examined plant extracts, followed by minor quantities of quercetin and kaempferol.
Reversed-Phase Liquid Chromatographic Profile of Free Amino Acids in Strawberry-tree (Arbutus unedo L.) Honey
Authors: Spano Nadia , Piras Irene , Ciulu Marco , Floris Ignazio , Panzanelli Angelo , Pilo Maria I , Piu Paola C , Sanna Gavino
Published: February 2020

The typical profile of the free amino acids contained in strawberry-tree (Arbutus unedo L.) honey is reported for the first time. An optimized reversed-phase liquid chromatographic (RP-LC) method with phenyl isothiocyanate precolumn derivatization was used. Fourteen free amino acids were identified and quantified in 16 analytical samples. Proline (65.63) was found to be the most abundant free amino acid, followed by glutamic acid (6.49), arginine (5.21), alanine (5.17), and phenylalanine (4.97). The total free amino acid content of strawberry-tree honey (average value, 436 mg/kg) was found to be low in comparison to amounts cited in the literature concerning unifloral honeys. The analytical method was optimized and fully validated in terms of detection and quantitation limits, precision (by testing repeatability and reproducibility), linearity, and bias (by means of recovery tests). The acceptability of the validation protocol results was verified using Horwitz's mathematical model and AOAC guidelines.
Trans Fatty Acids: Current Contents in Canadian Foods and Estimated Intake Levels for the Canadian Population
Authors: Ratnayake W M Nimal , L'Abbe Mary R , Farnworth Sara , Dumais Lydia , Gagnon Claude , Lampi Brian , Casey Valerie , Mohottalage Dayani , Rondeau Isabelle , Underhill Lynne , Vigneault Michele , Lillycrop William , Meleta Mary , Wong Lynn Y , Ng Tran , Gao Yu , Kwong Keri , Chalouh Shirley , Pantazopoulos Peter , Gunaratna Hasantha , Rahardja Adeline , Blagden Richard , Roscoe Veronica , Krakalovich Thomas , Neumann Gary , Lombaert Gary A
Published: February 2020

Research conducted in the mid-1990s indicated that the levels of Trans fats in Canadian diets were among the highest in the world. The consumption of Trans fats raises blood levels of low-density lipoprotein (LDL)-cholesterol, while reducing levels of high-density lipoprotein (HDL)-cholesterol. In June 2007, Health Canada called on the food industry to voluntarily reduce levels of Trans fats in vegetable oils and soft (tub)-margarines to <2 of total fat, and in all other foods, to <5. Industry must show satisfactory progress by June 2009, or Health Canada might have to introduce legislation to ensure that recommended limits are achieved. Since 2005, Health Canada has been performing a national assessment of prepackaged and restaurant foods that likely contain Trans fats. From 2005 to 2009, 1120 samples were analyzed, of which 852 or approximately 76 met the recommended Trans fat limits. As a result of reformulation, most of the products had decreased Trans + saturated fat content. The estimated average intake of Trans fatty acids (TFA) in Canada significantly dropped from the high value of 8.4 g/day in the mid-1990s to 3.4 g/day (or 1.4 food energy) in 2008. However, this TFA intake of 1.4 of energy is still above the World Health Organization recommended limit of TFA intake of <1 of energy, which suggests that the Canadian food industry needs to put more effort into reducing the TFA content in its products, especially in tub-margarines, donuts, and bakery products.
Validation of a Liquid Chromatographic/Tandem Mass Spectrometric Method for the Determination of Scopolamine Butylbromide in Human Plasma: Application of the Method to a Bioequivalence Study
Authors: Manfio Josélia Larger , dos Santos Mauricio Bedim , Favreto Wagner Alex Jann , Hoffmann Fabiane Ines , Mertin Adriana Cristina
Published: February 2020

A sensitive and specific LC/MS/MS method was developed and validated for the determination of scopolamine butylbromide in human plasma. Scopolamine butylbromide and propanolol (internal standard) were extracted from the plasma by liquidliquid extraction with dichloromethane as the extraction solvent and separated on a C18 analytical column (50 4.6 mm id) maintained at 40C. The analytes were eluted at a constant flow rate of 0.45 mL/min; the mobile phase consisted of acetonitrile and a buffer of 5 mM ammonium acetate and 0.1 formic acid (60 + 40, v/v). The mass spectrometer, equipped with an electrospray source in the positive ionization mode, was set up in the multiple-reaction monitoring mode to monitor the transitions m/z 360.6 > 102.5 (scopolamine butylbromide) and m/z 259.7 > 115.6 (propanolol). The chromatographic separation was obtained within 2.0 min, and the responses were linear over the concentration range of 0.1040.00 ng/mL. The mean extraction recoveries of scopolamine butylbromide and propanolol from plasma were 69.00 and 80.76, respectively. Method validation parameters, such as specificity, linearity, precision, accuracy, and stability, were within the acceptable range. Moreover, when the proposed method was successfully applied to a pharmacokinetic study of healthy human volunteers, the results showed that the two scopolamine butylbromide formulations tested are not bioequivalent in rate and extent of absorption.
Determination of Carmine Food Dye (E120) in Foodstuffs by Stripping Voltammetry
Authors: Alghamdi Ahmad H , Alshammery Hamed M , Abdalla Mohamed A , Alghamdi Ali F
Published: February 2020

The behavior of the food colorant agent carmine (E120) was studied by square-wave adsorptive stripping voltammetry (SW-AdSV) at the hanging mercury drop electrode. It was observed that carmine gave a sensitive stripping voltammetric peak at 350 mV in pH 3 acetate buffer. The cyclic voltammetric technique was also used to characterize the electrochemical reduction process of carmine. The adsorptive voltammetric signal was evaluated with respect to various experimental conditions, and the optimized values were supporting electrolyte, acetate buffer; buffer acidity, pH 3; dye concentration, 3 107 M; accumulation time, 150 s; accumulation potential, 0.2 V; scan rate, 300 mV/s; pulse amplitude, 185 mV; SW frequency, 20 Hz; working electrode area, 0.6 mm2; and convection rate, 2600 rpm. The SW-AdSV peak currents depended linearly on the concentration of carmine from 5 108 to 1.25 107 mol/L (r 0.99). A detection limit of 1.43 109 mol/L with an RSD of 2.2 and a mean recovery of 97.9 were obtained. Possible interferences by several substances usually present in food products such as food additive dyes (E102, E100, E123, E127, and E129), artificial sweeteners, preservatives, and antioxidants were also evaluated. The proposed electrochemical procedure was successfully applied to the determination of carmine food dye in spiked commercially available ice cream and soft drinks.
Improvement of AOAC Official Method 984.27 for the Determination of Nine Nutritional Elements in Food Products by Inductively Coupled Plasma-Atomic Emission Spectroscopy After Microwave Digestion: Single-Laboratory Validation and Ring Trial
Authors: Poitevin Eric , Nicolas Marine , Graveleau Laetitia , Richoz Janique , Andrey Daniel , Monard Florence ,   Collaborators:, Abrahamson A , Baillon A , Barrios J , Berger S , Berrocal R , Bos R , Brullebaut L , Caseiro C , Choo L F , Cole G , Daix G , Dekussche C , Dhillon G-S , Fortineau A , Gaudin C , Gonzales M J , Leal R , Mabiog R O , Noorlos T , Reba R , Senechal C
Published: February 2020

A single-laboratory validation (SLV) and a ring trial (RT) were undertaken to determine nine nutritional elements in food products by inductively coupled plasma-atomic emission spectroscopy in order to improve and update AOAC Official Method 984.27. The improvements involved optimized microwave digestion, selected analytical lines, internal standardization, and ion buffering. Simultaneous determination of nine elements (calcium, copper, iron, potassium, magnesium, manganese, sodium, phosphorus, and zinc) was made in food products. Sample digestion was performed through wet digestion of food samples by microwave technology with either closed or open vessel systems. Validation was performed to characterize the method for selectivity, sensitivity, linearity, accuracy, precision, recovery, ruggedness, and uncertainty. The robustness and efficiency of this method was proved through a successful internal RT using experienced food industry laboratories. Performance characteristics are reported for 13 certified and in-house reference materials, populating the AOAC triangle food sectors, which fulfilled AOAC criteria and recommendations for accuracy (trueness, recovery, and z-scores) and precision (repeatability and reproducibility RSD and HorRat values) regarding SLV and RT. This multielemental method is cost-efficient, time-saving, accurate, and fit-for-purpose according to ISO 17025 Norm and AOAC acceptability criteria, and is proposed as an improved version of AOAC Official Method 984.27 for fortified food products, including infant formula.
Multiresidue Analysis of Pesticides in Soil by High-Performance Liquid Chromatography with Tandem Mass Spectrometry
Authors: Fenoll José , Hellín Pilar , Martnez Carmen M , Flores Pilar
Published: February 2020

An analytical multiresidue method using HPLC/MS/MS with a triple-quadrupole mass spectrometer in the multiple reaction monitoring mode for the simultaneous determination of 54 pesticides in soil has been developed. The procedure involved initial single-phase extraction of soil sample with acetonitrile by sonication, followed by liquidliquid partitioning after addition of NaCl. The average recovery by the HPLC/MS/MS method obtained for these compounds varied from 63.2 to 113.8, with an RSD between 1.9 and 7.1. The method gave good linearity over the assay range of 10500 g/L (except famoxadone, 501000 g/L); the LOD and LOQ for the pesticides varied from 0.02 to 13.2 and from 0.1 to 43.9 g/kg, respectively. The proposed method was used to determine pesticide levels in soil samples from two experimental vineyards and two tomato greenhouses.
Measurement of Water-Soluble B Vitamins in Infant Formula by Liquid Chromatography/Tandem Mass Spectrometry
Authors: Huang Min , Winters Doug , Crowley Richard , Sullivan Darryl
Published: February 2020

A method has been developed for the simultaneous measurement of multiple B vitamins (i.e., B1, B2, B3, B5, and B6) in infant formulas by LC-MS/MS. The vitamins were extracted with acidic solvent, followed by protein precipitation at a pH range of 4.5 to 5.5, and filtered. This simplified procedure eliminates many of the potential sources of laboratory error and facilitates rapid and efficient analysis. As is common in most cases, isotope internal standards were added to account for variations in sample preparation, as well as changes in MS measurement. In this method, isotope-labeled internal standards of B1, B3, B5, and B6 were used. The factors affecting analytical performance were investigated and optimized. In addition, the stability of these vitamins in the extraction solution was investigated. An acidic condition (5 mM HCl) was applied to successfully stabilize B1, which had shown a decrease in signal when other solvents were used. The quantitative extraction and good stability allowed isotope standards to be added to the filtered sample solution, instead of to the extraction solvent. The addition of the isotope to the small portion of the filtered sample solution significantly reduces cost. A comprehensive evaluation of the analysis of the standard reference material and good spike recovery of the vitamins (100 6) demonstrates the accuracy of the method. The results for commercially available infant formula samples were also compared with those obtained using the current microbiological method.
GMOtrack: Generator of Cost-Effective GMO Testing Strategies
Authors: Novak Petra Kralj , Gruden Kristina , Morisset Dany , Lavrač Nada , Štebih Dejan , Rotter Ana , Žel Jana
Published: February 2020

Commercialization of numerous genetically modified organisms (GMOs) has already been approved worldwide, and several additional GMOs are in the approval process. Many countries have adopted legislation to deal with GMO-related issues such as food safety, environmental concerns, and consumers' right of choice, making GMO traceability a necessity. The growing extent of GMO testing makes it important to study optimal GMO detection and identification strategies. This paper formally defines the problem of routine laboratory-level GMO tracking as a cost optimization problem, thus proposing a shift from the same strategy for all samples to sample-centered GMO testing strategies. An algorithm (GMOtrack) for finding optimal two-phase (screeningidentification) testing strategies is proposed. The advantages of cost optimization with increasing GMO presence on the market are demonstrated, showing that optimization approaches to analytic GMO traceability can result in major cost reductions. The optimal testing strategies are laboratory-dependent, as the costs depend on prior probabilities of local GMO presence, which are exemplified on food and feed samples. The proposed GMOtrack approach, publicly available under the terms of the General Public License, can be extended to other domains where complex testing is involved, such as safety and quality assurance in the food supply chain.
Assurance GDS for Salmonella
Authors: Feldsine Phil , Hammack Thomas
Published: February 2020

A study was conducted to determine the efficacy of detecting low contamination levels of Salmonella in peanut butter using Assurance GDS for Salmonella (GDS). This study was conducted under the AOAC Research Institute Emergency Response Validation program. A set of samples was each analyzed by the GDS and the U.S. Food and Drug Administration's Bacteriological Analytical Manual reference method. Among the 45 total samples and controls, 26 samples were positive by the GDS and 24 were positive by the reference method. Statistical analyses of these unpaired samples indicated that, for all levels analyzed, the differences between the GDS and reference method results were not statistically different at the 5 level.
RapidChek SELECT Salmonella
Authors: Muldoon Mark T , Li Jingkun , Sutzko Meredith , Olsson-Allen Ann Christine , Teaney George , Gonzalez Verapaz , Hammack Thomas
Published: February 2020

RapidChek SELECT Salmonella was previously validated in the Performance Tested MethodsSM program for the detection of Salmonella spp. in raw ground chicken, chicken carcass rinse, sliced cooked turkey, and liquid eggs. The present matrix extension study conducted under the AOAC Research Institute Emergency Response Validation program compared the RapidChek SELECT Salmonella method to the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) method for the detection of Salmonella Typhimurium in peanut butter. Overall, 27 samples were found positive by the RapidChek SELECT Salmonella method and 27 were found to be positive by the reference method. All RapidChek SELECT Salmonella presumptive positives were confirmed positive by the cultural reference method; additionally, all presumptive negative results were confirmed negative by the cultural reference method. Accordingly 0 false-negative rate and 0 false-positive rate were found. No significant difference between the RapidCheck SELECT Salmonella and FDA-BAM reference method was found; calculated Chi-square was 0. Results indicate that a low level of Salmonella in peanut butter can be successfully recovered and detected in the minimum 24 h enrichment protocol.
Simultaneous Determination of Eight Sympathomimetic Amines in Urine by Gas Chromatography/Mass Spectrometry
Authors: Moawad Michael , Khoo Cheang S , Lee Samiuela , Hennell James R
Published: February 2020

A GC method was developed for the identification and quantitation of eight sympathomimetic amines in urine, i.e., amphetamine, methamphetamine, mephentermine, ephedrine, pseudoephedrine, methylenedioxyamphetamine, methylenedioxymethamphetamine, and methylenedioxyethylamphetamine. Methoxyphenamine was used as the internal standard (IS). The assay is rapid, sensitive, and simple to perform. It involves a liquidliquid extraction procedure with simultaneous in-solution derivatization of the organic layer with pentafluorobenzoyl chloride (PFB-Cl), followed by GC/MS analysis. These derivatives and the IS were extracted from 1 mL alkaline urine into hexane before derivatization with PFB-Cl. The organic layer was then removed and evaporated to dryness before dissolution with hexane for GC/MS analysis. Calibration curves for each analyte showed linearity in the range of 255000 ng/mL (r2 ≥ 0.997). Recoveries ranged from 88 to 99, with the precision of recoveries typically ≤5%. The LOD values ranged from 7 to 28 ng/mL, and the LOQ values ranged from 23 to 94 ng/mL. At least four ions were available for each analyte for confirmation of identity by MS.
Determination of Metformin Hydrochloride and Glyburide in an Antihyperglycemic Binary Mixture Using High-Performance Liquid Chromatographic-UV and Spectrometric Methods
Authors: Salem Hesham
Published: February 2020

Three methods were developed for simultaneous determination of metformin hydrochloride and glyburide in an antihyperglycemic binary mixture without previous separation. In the first method, a reversed-phase HPLC column with acetonitrilewater (60 + 40, v/v) mobile phase at 0.9 mL/min flow rate was used to separate both compounds, with UV detection at 254 nm. Linearity was obtained in the concentration range of 0.060.24 µg/mL for glyburide and 1.56.0 µg/mL for metformin hydrochloride. The second method depended on first- and second-derivative UV spectrometry with zero-crossing measurements. The first-derivative amplitude at 261 nm was selected for the assay of glyburide, and the second-derivative amplitude at 235 nm was selected for the assay of metformin hydrochloride. The third method depended on measuring the first derivative of the ratio-spectra at 241 nm for glyburide and 227 nm for metformin hydrochloride. For the second and third methods, Beer's law was obeyed in the range of 1055 µg/mL for glyburide and 20200 µg/mL for metformin. The proposed methods were extensively validated and applied for the analysis of some pharmaceutical formulations containing binary mixtures of the mentioned drugs.
Determination of Polycyclic Aromatic Hydrocarbons in Airborne Particulate Matter by Gas ChromatographyTriple Quadrupole Tandem Mass Spectrometry
Authors: Frenich Antonia Garrido , Ocaña Rosa Martínez , Vidal José L Martínez
Published: February 2020

An accurate and sensitive method for the identification and the quantification of 24 polycyclic aromatic hydrocarbons (PAHs) in airborne particulate matter has been developed and validated using GC/MS/MS with a triple quadrupole analyzer. Ultrasonic extraction (USE) and pressurized liquid extraction (PLE) were evaluated. PLE was selected because it provided better recoveries and reduced treatment time and use of solvents compared to USE. Cleanup of PLE extracts was not necessary. The accuracy of the optimized method was tested using a standard reference material of urban dust (SRM 1649a). PAH recoveries were between 70 and 99 (except for naphthalene, which was lower than 20) with RSDs ranging from 2.6 to 15.3. Linearity in the range 5500 ng/mL provided R2 values higher than 0.99 for all compounds. LODs for PAHs ranged from 0.001 to 0.435 ng/mL and LOQs ranged from 0.003 to 0.757 ng/mL. The proposed method was applied to the analysis of real samples collected in the city of Almera, Spain, where some PAHs were found at levels lower than the legislated limit.
Immunochromatographic Assay with Photometric Detection for Rapid Determination of the Herbicide Atrazine and Other Triazines in Foodstuffs
Authors: Byzova Nadezhda A , Zherdev Anatoly V , Zvereva Elena A , Dzantiev Boris B
Published: February 2020

An immunochromatographic system for detection of the herbicide atrazine and its structural analogues has been developed. The assay is based on the competition of atrazine and immobilized atrazine-protein conjugate for binding with anti-atrazine monoclonal antibodies. The antibodies are immobilized on colloidal gold particles with an average diameter of 30 nm under conditions providing stability of these complexes. Concentrations of reagents and regimens of their immobilization have been optimized in order to reach the minimal limit of atrazine detection. The assay is initiated by contact of the test strip with a liquid sample and does not need any additional reactants or treatment. Duration of the assay was 10 min. The colored line formed on the test strip was assessed quantitatively with a portable photometric device; the RSD in a series was 4.8-13.0%. The range of photometrically determined concentrations of atrazine was 130 ng/mL. Visual qualitative assay permitted detection of the disappearance of the colored line for atrazine concentrations starting at 100 ng/mL. Cross-reactivities of structurally similar herbicides correlated well for the proposed assay and traditional microplate ELISA. The applicability of the developed system for atrazine detection in milk and juices was confirmed.
Analysis of DDT Isomers with Enzyme-Linked Immunosorbent Assay and Optical Immunosensor Based on Rat Monoclonal Antibodies as Biological Recognition Elements
Authors: Krämer Petra M , Weber Cristina M , Forster Stephan , Rauch Peter , Kremmer Elisabeth
Published: February 2020

New rat monoclonal antibodies (mAbs) for DDT [1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane], namely DDT 7C12, DDT 1C1, and DDT 1B2, were developed, characterized, and applied in ELISA both in coating antigen and in enzyme-tracer format. The latter used horseradish peroxidase (HRP) or glucose oxidase as enzymes. The lowest concentration of p,p-DDT was determined with mAb DDT 7C12 and DDT-hapten HRP, with a test midpoint (IC50) of 0.5 ± 0.2 µg/L (n = 10) in 40 mM PBS (phosphate-buffered saline). The mouse anti-rat immunoglobulin lambda-light chain mAb LA1B12 was used as capture mAb. The best IC50 for o,p´-DDT in 40 mM PBS was 1.0 ± 0.3 µg/L (n = 12) and was obtained with mAb DDT 1C1 and DDT-hapten HRP, whereas mAb DDT 1B2 was very selective for p,p-DDT with an IC50 of 4.2 ± 1.6 µg/L (in 40 mM PBS, n = 9). An optical immunosensor was optimized and applied for the analysis of DDT (or DDT equivalents). This immunosensor consists of a bench-top optical readout device and disposable sensor chips, which include the fluidic system. Evanescent field excitation and emission of the fluorophore Oyster-645 was used. An IC50 for p,p´-DDT [in 5 (v/v) isopropanol in 40 mM PBS] of 4 µg/L was obtained using DDT 7C12-Oyster-645. ELISA and immunosensor were used for the analysis of p,p-DDT in unspiked and spiked surface water samples. Within the working ranges of these immunotechniques, recoveries ranged from 80 to 120.
Validation and Uncertainty Analysis of a Multiresidue Method for 67 Pesticides in Made Tea, Tea Infusion, and Spent Leaves Using Ethyl Acetate Extraction and Gas Chromatography/Mass Spectrometry
Authors: Kanrar Bappaditya , Mandal Sudeb , Bhattacharyya Anjan
Published: February 2020

A rapid, specific, and sensitive multiresidue method to determine 67 pesticides in made tea, tea infusion, and spent leaves was developed and validated for routine analysis by GC/MS with an approximately 29 min GC run time. The method was reproducible (HorRat <0.5 at 50 ng/g) when validated at 50 and 100 ng/g. The samples were extracted with ethyl acetatecyclohexane (9 + 1, v/v), and the extracts were cleaned up by dispersive SPE with primary-secondary amine sorbent + graphitized carbon black + Florisil. The recoveries of all the pesticides were within 70120 with an RSD of <20 at 50 ng/g and R2 > 0.99. The matrix effect on the signals of the compounds was corrected by using matrix-matched calibration standards. The LOQ met the requirements of the maximum residue limits for pesticides in tea as recommended by the European Union.
Differentiating Cross-Reacting Allergens in the Immunological Analysis of Celery (Apium graveolens) by Mass Spectrometry
Authors: Fæste Christiane K , Jonscher Karen R , Sit Louis , Klawitter Jelena , Løvberg Kjersti E , Moen Lena H
Published: February 2020

Celery is acknowledged as a major food allergen in Europe, and mandatory labeling for preprocessed foods has been implemented. However, no methods for the specific detection of celery protein in foods have been published. In the present study, a sandwich celery ELISA using polyclonal anticelery antibodies for capture and detection was developed and validated. The method has an LOD of 0.5 mg/kg in buffer; however, it is applicable only for the screening of food products because of extensive cross-reactivity with potato and carrot proteins. Using nanoLCion-trap MS/MS, a number of proteins in the three vegetable species were identified as candidates for causing cross-reactions due to amino acid sequence homologies. Among others, a novel patatin (Sola t 1)-like protein was detected in celery and a flavin adenine dinucleotide binding domain-containing protein (Api g 5)-like protein was identified in carrot. The utility of triple-quadrupole MS/MS for specific and quantitative analysis of celery, potato, and carrot allergens was evaluated using whole protein extracts. Several unique precursor ion-to-product ion transitions were determined for each species, suggesting the feasibility of developing an MS-based screening method to specifically detect celery allergens in foods.
Determination of Indoxacarb Enantiomer Residues in Vegetables, Fruits, and Soil by High-Performance Liquid Chromatography
Authors: Cheng Li , Dong Feng-Shou , Liu Xingang , Chen Wuying , Li Yuanbo , Zheng Yongquan , Qin Dongmei , Gong Yong
Published: February 2020

An effective chiral analytical method was developed for the resolution and determination of indoxacarb enantiomers in cucumber, tomato, apple, pear, and soil samples. Indoxacarb enantiomers were separated on a Chiralpak AS-H column with n-hexaneethanol (95 + 5, v/v) as the mobile phase. Validation involved complete resolution of each enantiomer, plus determination of linearity, precision, LOD, and LOQ. The estimated LOD was 0.0250.035 mg/kg, and the LOQ was 0.05 mg/kg for each indoxacarb enantiomer in different matrixes. The average recoveries of the pesticide from all matrixes ranged from 87.0 to 116.9 for fortification levels of 0.05, 0.1, and 5 mg/kg. The precision values associated with the analytical method, expressed as RSDr values, were <10.1 for the pesticide in all matrixes. This method can be used to evaluate environmental residues and the safety of agricultural products.
Review of HPTLC in Drug Analysis: 1996-2009
Authors: Sherma Joseph
Published: February 2020

Analytical methods for drug substances, formulations, and clinical samples developed and validated on HPTLC plates during the period 19962009 are reviewed. Procedures, materials, and instrumentation for the different steps in the HPTLC procedure and validation of results; applications to bulk drugs, formulations, stability studies, biological samples (e.g., urine and plasma), and hydrophobicity studies; and prospects for the use of HPTLC for drug analysis in the future are described.
Development and Validation of a Novel Stability-Indicating Reversed-Phase High-Performance Liquid Chromatography Method for Assay of Loratadine and Determination of Its Related Compounds
Authors: Lu Jun , Wei Yu-Chien , Markovich Robert J , Rustum Abu M
Published: February 2020

Loratadine is an important active pharmaceutical ingredient used in a wide variety of prescription and over-the-counter products for the treatment and relief of allergy symptoms. A novel stability-indicating gradient ion-pair RP-HPLC method for assay of loratadine and determination of both of its degradation compounds and process impurities has been developed. This method can separate loratadine from its eight structurally related compounds; it can also separate all of the related compounds from each other in less than 20 min. The stability-indicating capability of this method has been demonstrated by analyzing aged stability samples of loratadine. A 15 cm 4.6 mm id YMC-Pack Pro C18 HPLC column was the primary column and a 15 cm 4.6 mm id SunFire C18 column has been identified as an alternate (truly equivalent) column for this method. This gradient method uses mobile phases consisting of acetonitrile and an aqueous solution of 10 mM sodium acetate and 5 mM sodium dodecyl sulfate at pH 5.5. The new HPLC method was validated according to International Conference on Harmonization guidelines and proved to be suitable for routine QC use.
Comparison of FoodChek E. coli Test and AOAC Research Institute Performance Tested Method 010603 for Detection of E. coli O157 in Raw Ground Beef
Authors: Flanagan Richard J , Martinez Gabriela
Published: February 2020

The FoodChek E. coli O157 assay [AOAC Research Institute (RI) Performance Tested Method (PTM) 060902] is a rapid detection system that incorporates the use of antibody-coated superparamagnetic nanoparticles in a lateral flow immunoassay format. The system comprises a commercially available enrichment medium, a magnetic nanoparticle immunoassay, and an automated reader for detection. Assay detection threshold is improved relative to traditional immunoassays through use of a magnetic nanoparticle label and a highly sensitive magnetic particle detector. FoodChek E. coli O157 is a reintroduction of the previously certified AOAC PTM 010603. The original assay was evaluated and approved in internal and independent laboratory studies. Vacci-Test Corp. has contracted with the original supplier of the PTM to remanufacture the test under identical conditions and with identical raw materials. This report is intended to show that FoodChek E. coli is identical in performance to the previously approved PTM. The results showed no difference for the parameters evaluated. Three kit lots along with three lots of media and media supplement were compared in lot-to-lot and stability testing. The results indicated no difference in performance across the three lots. The results showed sensitivity of >99 and a specificity rate of >98 for the FoodChek method and a significantly higher sensitivity than the reference method.
Correlation Between Aflatoxin Contamination and Various USDA Grade Categories of Shelled Almonds
Authors: Whitaker Thomas B , Slate Andy , Birmingham Tim , Adams Julie , Jacobs Merle , Gray Gary
Published: February 2020

The California almond industry is interested in determining if there is a correlation between aflatoxin contamination and almonds classified into various U.S. Department of Agriculture (USDA) grades. A 12 000 g sample was taken from each of 50 lots of shelled almonds. The almonds in each sample were then partitioned into five USDA grades: high quality (HQ), insect damage (ID), mold damage (MOD), mechanical damage (MED), and other defects (OD). Across all 50 samples, kernels in the HQ grade accounted for 83.7 of the kernel mass and 3.2 of the aflatoxin mass. Conversely, kernels in the remaining four damage grades (ID, MOD, MED, and OD) accounted for 16.3 of the kernel mass and 96.8 of the aflatoxin mass. ID kernels had the highest risk for aflatoxin contamination. Almonds in the ID grade accounted for 76.3 of the total aflatoxin mass and 7.2 of the kernel mass. Regression equations were developed to predict the aflatoxin concentration in each 12 000 g sample by measuring the aflatoxin mass in one or more of the four damage grades. Regression equations demonstrated that aflatoxin mass only in the insect damaged kernels was also an effective way to predict the aflatoxin concentration in each 12 000 g sample.
Validation of a Column Liquid Chromatographic Method for the Analysis of Pramipexole and Its Five Impurities
Authors: Malenović Andjelija , Jančić-Stojanović Biljana , Vemić Ana , Ivanović Darko , Medenica Mirjana
Published: February 2020

In this paper, a previously optimized method for HPLC analysis of pramipexole and its impurities was subjected to method validation in accordance with official regulations. The optimized chromatographic conditions were as follows: mobile phase acetonitrilewater phase [15 + 85, v/v, water phase contained 1 triethylamine (TEA), pH adjusted to 7.0 with orthophosphoric acid]; detection at 262 nm for pramipexole, BI-II 751 xx, BI-II 786 BS, BI-II 820 BS, and 2-aminobenzothiazole and at 326 nm for BI-II 546 CL; column temperature, 25C; and flow rate, 1 mL/min. Acetonitrile and TEA content, pH of the water phase, flow rate, column temperature, and column type were factors studied in robustness testing. According to the experimental plan defined by a Plackett-Burman design, five dummy variables were added in order to have 12 factors. As output, resolution factor was chosen. Robustness was assessed by graphical (half-normal probability plots and Pareto charts) and statistical (t-test) methods. Also, nonsignificance intervals for significant factors were estimated, and limits for the system suitability test were determined. Finally, linearity, accuracy, and precision of the proposed HPLC method were defined. LOD and LOQ values for analyzed impurities were determined. The method was completely defined by these experiments.
High-Performance Liquid Chromatographic Determination of Pantoprazole and Its Main Impurities in Pharmaceuticals
Authors: Letica Jelena , Marković Slavko , Zirojević Jelena , Nikolić Katarina , Agbaba Danica
Published: February 2020

An RP-HPLC method for simultaneous separation and quantification of pantoprazole and its five main impurities in pharmaceutical formulations was developed and validated. The separation was accomplished on a Zorbax Eclipse XDB C18 column (5 m particle size, 150 4.6 mm id) using a gradient with mobile phase A [bufferacetonitrile (70 + 30, v/v)], and mobile phase B [bufferacetonitrile (30 + 70, v/v)]. The buffer was 0.01 M ammonium acetate solution with addition of 1 mL triethylamine/L of the solution, adjusted to pH 4.5 with orthophosphoric acid. The eluent flow rate was 1 mL/min, the temperature of the column was 30C, and the eluate was monitored at 290 nm. Linearity (r = 0.999), recovery (97.6105.8), RSD (0.551.90), and LOQ (0.0991.48 g/mL) were evaluated and found to be satisfactory. The proposed method can be used for simultaneous identification and quantification of the analyzed compounds in pharmaceutical formulations.