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Journal of AOAC International

Tamer M A M Thabit, Dalia I H Elgeddawy
Phosphine is considered the main fumigant material used for long time for controlling insect pests in stored grains. This research was focused on the determination of phosphine residues in cereal matrices (mainly wheat and corn) after the fumigation process, using a new procedure developed to reduce the number of analytical steps and improve the chromatographic separation, identification, and quantitation of analyte, thus leading to enhanced total efficiency and sensitivity. This method, using gastight vials for extraction with 5% sulfuric acid, a heating extraction sequence, and injection with headspace and GC-MS in selected-ion monitoring mode, gave clean separation and accurate results...
September 22, 2017: Journal of AOAC International
Abdul Haleem Panhwar, Mustafa Tuzen, Tasneem Gul Kazi
An innovative and effective digestion method based on choline chloride (ChCl)–oxalic acid (Ox) deepeutectic solvent (DES) was proposed for the determination of Se and As in fish samples via electrothermal atomic absorption spectrometry (ETAAS). The impacts of different variables, including the composition and volume of ChCl–Ox, temperature, and acid addition, on analyte recovery were studied for optimization. In this procedure, an 80 mg sample was dissolved in a 1:2 molar ratio of ChCl–Ox at 105°C for 40 min, with the subsequent addition of 4...
September 21, 2017: Journal of AOAC International
Sooraj Nizamani, Tasneem G Kazi, Hassan I Afridi, Sehrish Talpur, Ayaz Lashari, Anjum Lashari, Jamshed Ali
A simple vortex-assisted modified dispersive liquid–liquid microextraction procedure is proposed forthe enrichment of cadmium (Cd(+2)) in surface (stored rainwater) and groundwater of the Tharparkar district in Pakistan, before analysis by flame atomic absorption spectrometry. Ammonium pyrrolidinedithiocarbamate was used as a ligand to make a hydrophobic complex of Cd(+2), which was extracted in an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate), and the nonionic surfactant Triton X-114 was applied as a dispersing medium...
September 21, 2017: Journal of AOAC International
Cortlandt P Thienes, Jongkit Masiri, Lora A Benoit, Brianda Barrios-Lopez, Santosh A Samuel, David P Cox, Anatoly P Dobritsa, Cesar Nadala, Mansour Samadpour
Recent news of many cases of adulteration of meats with pork has bolstered the need for a way to detect and quantify the unwanted contamination of pork in other meats. To address this need, Microbiologique, Inc. has produced a sandwich ELISA assay that can rapidly quantify the presence of pork in cooked horse, beef, chicken, goat, and lamb meats. We carried out a validation study and showed that this assay has an analytical sensitivity of 0.00014 and 0.00040% (w/v) for cooked and autoclaved pork, respectively, and an analytical range of quantitation of 0...
September 19, 2017: Journal of AOAC International
Yan Jin, Kyung Min Jeong, Jeongmi Lee, Jing Zhao, Su-Young Choi, Kwang-Soo Baek
The dried inner bark of Tabebuia impetiginosa, known as taheebo or red lapacho, has numerous beneficial effects on human health. This study presents the first simple and reliable quantitative method that could serve for the QC of taheebo. The method uses LC–UV spectroscopy to determine the veratric acid (VA; 3,4-dimethoxybenzoic acid) content of taheebo extracts (TEs). Sample preparation entailed the dissolution of TE in methanol (MeOH), facilitated by ultrasonic radiation for 10 min. The optimized conditions included chromatographic separation on an Agilent Eclipse Plus C18 column (4...
September 19, 2017: Journal of AOAC International
Bei Yan, Yao Liu, Aixin Shi, Zhihong Wang, Jiye Aa, Xiaoping Huang, Yi Liu
Ginseng is usually used for alleviating fatigue. The purpose of this paper was to evaluate the regulatory effect of Korean ginseng on the metabolic pattern in professional athletes, and, further, to explore the underlying mechanism of the antifatigue effect of Korean ginseng. GC-time-of-flight-MS was used to profile serum samples from professional athletes before training and after 15 and 30 day training, and professional athletes administered with Korean ginseng in the meanwhile. Biochemical parameters of all athletes were also analyzed...
September 19, 2017: Journal of AOAC International
Sehrish Talpur, Tasneem Gul Kazi, Hassan Imran Afridi, Farah Naz Talpur, Sooraj Nizamani, Anjum Lashari, Asma Akhtar, Mustafa Khan
In the present study, a simple ultrasonically dispersed modified liquid-phase microextraction method was developed for the extraction of lead (Pb) from blood and scalp hair samples of malnourished children (MNC). The complexation of Pb was executed by means of the complexing agent, ammonium pyrrolidinedithiocarbamate (APDC), whereas extraction was carried out through the ionic liquid (IL), 1-butyl-3-methylimidazolium hexafluorophosphate. Ultrasound energy was used for the dispersion and extraction of the metal complex into an IL because it enhances the extraction of the metal complex into infinite IL drops at a temperature range of 40–80°C for 1–5 min...
September 19, 2017: Journal of AOAC International
Jonathan Draher, Norman White
A method for tryptophan (Trp) analysis designed to comply with AOAC Standard Method Performance Requirement 2014.013 is described. Unlike AOAC 988.15, which uses alkaline hydrolysis, this method uses enzymatic hydrolysis to release the Trp from the intact protein. The method achieves an LOQ of 0.18 mg/100 g Trp on a ready-to-feed basis with mean recoveries ranging from 93.8 to 104.9%. Repeatability ranged from 0.2 to 5.0%. Intermediate precision ranged from 1.0 to 6.9%. The analytical range was determined to be 0...
September 19, 2017: Journal of AOAC International
Christine K Nessim, Adel M Michael, Yasmin M Fayez, Hayam M Lotfy
Two simple and accurate chemometric-assisted spectrophotometric models were developed and validated for the simultaneous determination of chlordiazepoxide (CDZ) and clidinium bromide (CDB) in the presence of an alkali-induced degradation product of CDB in their pure and pharmaceutical formulation. Resolution was accomplished by using two multivariate calibration models, including principal component regression (PCR) and partial least-squares (PLS), applied to the UV spectra of the mixtures. Great improvement in the predictive abilities of these multivariate calibrations was observed...
September 19, 2017: Journal of AOAC International
Sarah Adriana R Soares, Silvânio Silvério L Costa, Rennan Geovanny O Araujo, Leonardo Sena Gomes Teixeira, Alailson Falcão Dantas
Three spectrophotometric methods were developed for the determination of copper (Cu) in sugar cane spirit using the chromogenic reagents neocuproine, cuprizone, and bathocuproine. Experimental conditions, such as reagent concentration, reducer concentration, pH, buffer concentration, the order of addition of reagents, and the stability of the complexes, were optimized. The work range was established from 1.0 to 10.0 µg/mL, with correlation coefficients of >0.999 for all three optimized methods. The methods were evaluated regarding accuracy by addition and recovery tests at five concentration levels, and the obtained recoveries ranged from 91 to 105% (n = 3)...
September 15, 2017: Journal of AOAC International
Swapna Gone, Nicolas Kosa, Joseph Krebs
Bioo Scientific Corp. has developed a rapid enzymatic quantitative assay for the determination of histamine inseafood. Fresh/frozen tuna, canned tuna, pouched tuna, and frozen mahi mahi samples were used for the validation study under the specific guidelines of the AOAC Research Institute Performance Tested Methods(SM) program. Recoveries ranged from 82 to 107% at concentrations ranging from 6 to 72 ppm, with RSDr values between 0.8 and 6.5% (6-72 ppm). The linearity of the assay ranged from 0 to 108 ppm, with R² values exceeding 0...
September 15, 2017: Journal of AOAC International
Irshad M Sulaiman, Pratik Banerjee, Ying-Hsin Hsieh, Nancy Miranda, Steven Simpson, Khalil Kerdahi
Staphylococcus spp. is considered as one of the most common human-pathogenic bacteria, causing illnesses ranging from nonthreatening skin infections to lethal diseases, including sepsis, pneumonia, bloodstream infections, and food poisoning. The emergence of methicillin-resistant Staphylococcus aureus strains has increased morbidity and mortality and resulted in a major healthcare burden worldwide. Single and multilocus sequence typing have been extensively used in the identification of Staphylococcus species...
September 15, 2017: Journal of AOAC International
Samah S Abbas, Maha A Hegazy, Hassan A M Hendawy, Soheir A Weshahy, May H Abdelwahab
Two specific, sensitive, and precise stability-indicating chromatographic methods have been developed for thedetermination of triamcinolone acetonide (TMC) and its coformulated drug, econazole nitrate (ECZ), in the presence of TMC impurities and degradation products. The first method was based on HPTLC-spectrodensitometry in which resolution and quantitation was achieved by using silica gel 60 F254 HPTLC plates and an ethyl acetate–tetrahydrofuran–ammonia mobile phase (10.0 + 7.0 + 0.1, v/v/v)...
September 14, 2017: Journal of AOAC International
Susan Alles, Evan Meister, Edan Hosking, Eric Tovar, Rebecca Shaulis, Mark Schonfeld, Lei Zhang, Lin Li, Preetha Biswas, Mark Mozola, Robert Donofrio
A study was conducted to validate a minor reagent formulation change to the ANSR for Listeria method, Performance Tested Method(SM) 101202. This change involves increasing the master mix volume prelyophilization by 40% and addition of salmon sperm DNA (nontarget DNA) to the master mix. These changes improve the robustness of the internal positive control response and reduce the possibility of obtaining invalid results due to weak-positive control curves. When three foods (hot dogs, Mexican-style cheese, and cantaloupe) and sponge samples taken from a stainless steel surface were tested, no significant differences in performance between the ANSR and U...
September 14, 2017: Journal of AOAC International
Ilgin Aydin, Dotse Selali Chormey, Türkan Budak, Merve Fırat, Fatma Turak, Sezgin Bakirdere
A dispersive liquid–liquid microextraction (DLLME) technique based on a solidification-of-floating-organic-drop (SFOD) procedure was developed for the determination of trace amounts of cadmium (Cd) by using a flame atomic absorption spectrometer (FAAS) fitted with a slotted quartz tube (SQT). The extraction of Cd was achieved by forming a complex with diphenylcarbazone. Parameters affecting the formation of complex and extraction outputs were carefully optimized to obtain high-absorbance signals to achieve lower LODs...
September 14, 2017: Journal of AOAC International
Karen J Schimpf, Linda D Thompson, Shang-Jing Pan
This reversed-phase HPLC method uses C30 chromatography and UV-Vis spectroscopy to determine cis and trans isomers of lutein, β-carotene, and lycopene in infant, pediatric, and adult nutritionals. Samples are saponified with a mixture of potassium hydroxide, tetrahydrofuran, and methanol, and carotenoids are extracted from saponified samples with 75 + 25 hexane–methyl tertiary butyl ether (MtBE). After extraction, a portion of the organic layer is evaporated to dryness, and the residue is dissolved in 75 + 25 10% butylated hydroxytoluene in methanol–MtBE...
September 12, 2017: Journal of AOAC International
Ying-Hsin Hsieh, Yun F Wang, Hercules Moura, Nancy Miranda, Steven Simpson, Ramnath Gowrishankar, John Barr, Khalil Kerdahi, Irshad M Sulaiman
Campylobacteriosis is an infectious gastrointestinal disease caused by Campylobacter spp.In most cases, it is either underdiagnosed or underreported due to poor diagnostics and limited databases. Several DNA-based molecular diagnostic techniques, including 16S ribosomal RNA (rRNA) sequence typing, have been widely used in the species identification of Campylobacter. Nevertheless, these assays are time-consuming and require a high quality of bacterial DNA. Matrix-assisted laser desorption ionization (MALDI) time-of-flight (TOF) MS is an emerging diagnostic technology that can provide the rapid identification of microorganisms by using their intact cells without extraction or purification...
September 12, 2017: Journal of AOAC International
Francesca Lambertini, Daniele Cavanna, Dante Catellani, Mario Li Vigni, Caterina Durante, Alessandro D'Alessandro, Michele Suman
Semolina pasta represents one of the most important dishes in Italian cuisine worldwide. Italy is the leader in its production and, recently, the worldwide diffusion of its production has begun to grow tremendously. The perceived quality of a food product, such as pasta, is a key feature that allows a company to increase and maintain the competitive advantage of a specific brand. The overall flavor perception of the consumer, therefore, has become as important as other key quality factors such as texture and color; thus, the food industry needs to meet consumer expectations and needs the tools to objectively “measure” the quality of food products...
September 12, 2017: Journal of AOAC International
Mamdouh R Rezk, Ahmed S Fayed, Hoda M Marzouk, Samah S Abbas
The chromatographic analysis of either process-related impurities or degradation products is very important inthe pharmaceutical industry. In this work, a simple, selective, and sensitive HPTLC method was developed and validated for the simultaneous determination of zofenopril calcium (ZOF) and hydrochlorothiazide (HCT) in the presence of the HCT impurities: A) chlorothiazide (CT) and B) salamide, in raw materials and in pharmaceutical formulation. The separation was carried out on HPTLC silica gel 60 F254 using ethyl acetate–glacial acetic acid–triethylamine (10 + 0...
September 11, 2017: Journal of AOAC International
Ahmet Kemal Aloglu, Peter de B Harrington
Bovine, porcine, and fish gelatins have been differentiated based on their spectra collected by attenuated total reflectance FTIR spectroscopy (ATR-FTIRS) coupled with pattern recognition. Three tree-based classification methods, a fuzzy rule-building expert system (FuRES), support vector machine classification trees (SVMTreeG and SVMTreeH), and one reference model, super partial least-squares discriminant analysis (sPLS-DA), were evaluated with and without two preprocessing techniques, namely standard normal variate (SNV) and principal component orthogonal signal correction (PC-OSC)...
September 8, 2017: Journal of AOAC International
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