Dickinsonlykke2084
The cleanup effect of GCB was much superior to that of PSA, C18, and their combinations. The solvent exchange step with hexane was effective in removing co-extractives and minimizing matrix effects.
This method complies with the regulatory requirements and is fit-for-purpose for pesticide residue monitoring in turmeric.
The study reports a validated GC-MS/MS method for multi-residue analysis of pesticides in turmeric for the first time. The method provided a high throughput analysis of multi-class pesticides in turmeric rhizome and powder matrices with satisfactory selectivity, sensitivity, accuracy, and precision.
The study reports a validated GC-MS/MS method for multi-residue analysis of pesticides in turmeric for the first time. The method provided a high throughput analysis of multi-class pesticides in turmeric rhizome and powder matrices with satisfactory selectivity, sensitivity, accuracy, and precision.
The Solus One Salmonella immunoassay utilizes Salmonella specific selective media and automated liquid handling, for the rapid and specific detection of Salmonella species in select food types.
The candidate method was evaluated using 375 g test portions in an unpaired study design for a single matrix, instant non-fat dry milk (NFDM) powder.
The matrix was compared to the United States Food and Drug Administration/Bacteriological Analytical Manual (FDA/BAM) Chapter 5 Salmonella reference method. Eleven participants from 10 laboratories within academia and industry, located within the United States, Mexico, South Africa, Germany, and the United Kingdom, contributed data for the collaborative study. Three levels of contamination were evaluated for each matrix an uninoculated control level [0 colony forming units (CFU)/test portion], a low inoculum level (0.2-2 CFU/test portion) and a high inoculum level (2-5 CFU/test portion). Statistical analysis was conducted according to the Probability of Detection (POD) statistical model.
Results obtained for the low inoculum level test portions produced a dLPOD value with a 95% confidence interval between the candidate method confirmed (both alternative and conventional confirmation procedures) and the reference method of 0.07 (-0.02, 0.15).
The dLPOD results indicate equivalence between the candidate method and the reference method for the matrix evaluated and the method demonstrated acceptable inter-laboratory reproducibility as determined in the collaborative evaluation. False positive and false negative rates were determined for the matrix and produce values of <2%.
Based on the data generated, the method demonstrated acceptable inter-laboratory reproducibility data and statistical analysis.
Based on the data generated, the method demonstrated acceptable inter-laboratory reproducibility data and statistical analysis.
There are several statistical methods for detecting a difference of detection rates between alternative and reference qualitative microbiological assays in a single laboratory validation study with a paired design.
We compared performance of eight methods including McNemar's test, sign test, Wilcoxon signed-rank test, paired t-test, and the regression methods based on conditional logistic (CLOGIT), mixed effects complementary log-log (MCLOGLOG), mixed effects logistic (MLOGIT) models, and a linear mixed effects model (LMM).
We first compared the minimum detectable difference in the proportion of detections between the alternative and reference detection methods among these statistical methods for a varied number of test portions. We then compared power and type 1 error rates of these methods using simulated data.
The MCLOGLOG and MLOGIT models had the lowest minimum detectable difference, followed by the LMM and paired t-test. The MCLOGLOG and MLOGIT models had the highest average power but were anticonservative when correlation between the pairs of outcome values of the alternative and reference methods was high. The LMM and paired t-test had mostly the highest average power when the correlation was low and the second highest average power when the correlation was high. Type 1 error rates of these last two methods approached the nominal value of significance level when the number of test portions was moderately large (n > 20).
The LMM and paired t-test are better choices than other competing methods, and we provide an example using real data.
The LMM and paired t-test are better choices than other competing methods, and we provide an example using real data.
Niacin (NIA) is a water-soluble vitamin and the primary treatment of pellagra. No analytical method was found to assess NIA in complex mixtures with its official impurities.
Two validated, accurate, and selective chemometric models were developed to assay NIA in the presence of its four official impurities, including pyridine, a nephrotoxic and hepatotoxic substance. Additionally, the two selective chemometric models were compared by processing UV spectra in the range 220-305 nm and applying partial least squares regression (PLSR) and support vector regression (SVR) models.
A five levels five factors experimental design was chosen to exhibit a training set of 25 mixtures that had numerous variable percentages of tested substances. A test set consisting of 10 mixtures was designed to confirm the predictive power of the suggested models.
The presented results substantiate the strength of the developed multivariate calibration models to assay NIA specifically with high selectivity and accuracy (100.02 ± 1.312 and 100.04 ± 1.272 for PLSR and SVR models, respectively). The root mean square error of prediction for the validation set mixtures was applied as a main comparison tool and it was found to be 0.2016 and 0.1890 for PLSR and SVR models, respectively.
The results of the developed models and the reported HPLC method were statistically compared, where F-values and Student's t-tests did not show significant difference in regards to accuracy and precision. The SVR model proved to be more accurate than the PLSR model, producing a high generalization capacity, while PLSR was easy to implement and fast.
PixeeMo™ is a compact instrument that enables bacterial cell counting using microfluidic chips instead of counting of colonies on culture media. Chips containing electrodes, based on fluid, electric filtering and sorting technology (FES), allow the selection of bacterial cells from other components in the sample. In the United States (US), surface water or ground water affected by surface water must be treated to reduce the total microbial load to less than 500 CFU/mL. In Japan, drinking water regulations limit the total bacterial load to 100 CFU/mL.
To validate the PixeeMoTM aerobic bacteria method based on the Japanese regulation in the range of 30-300 CFU/mL in drinking water.
PixeeMoTM aerobic bacteria method was compared to the Standard Method for the Examination of Water and Wastewater (SMEWW) 9215B (2017) using naturally contaminated drinking water.
The maximum repeatability standard deviation of the PixeeMoTM method was 14.8%. The difference of mean log10 values between the PixeeMoTM and SMEWW 9215B methods ranged from -0.015 to 0.258. Similar results were obtained in the independent laboratory study.
The PixeeMoTM method is equivalent to that of the SMEWW 9215B methods. The product consistency and stability study demonstrated no significant difference within the expiration date. The robustness study confirmed that there was no effect within the expected range. The instrument variation study also demonstrated no significant difference among the data of three PixeeMoTM instruments.
Total counts of bacteria in drinking water can be determined accurately within 1 h with PixeeMoTM.
Total counts of bacteria in drinking water can be determined accurately within 1 h with PixeeMoTM.
Turmeric is a medicinal herb containing curcuminoids, used as quality markers in dietary supplements. In 2016, an AOAC First Action Official MethodSM was adopted for quantitation of curcuminoids and requires multi-laboratory reproducibility data for Final Action status.
To collect reproducibility data for the quantitation of curcuminoids in dietary supplements through the National Institutes of Health Office of Dietary Supplements/National Institute of Standards and Technology Quality Assurance Program (QAP).
Laboratories that participated in the QAP by following the Official Methods of AnalysisSM Method 2016.16, submitted data for ten turmeric products. Semagacestat The data were analyzed for mean, repeatability, and reproducibility standard deviations, repeatability, and reproducibility.
The initial data collection resulted in insufficient replicates (five) for each test sample to determine reproducibility, therefore laboratories were provided additional materials resulting in an incremental data approach. For hremental data multi-laboratory study. The method is suitable for quantitation of curcuminoids in most common dietary supplements.
Vancomycin, an antimicrobial, has many microbiological methods in literature, but it was not found any that follows the green chemistry principles.
The aim of this work was to develop and validate a new microbiological analytical method with a green view to determine the vancomycin potency in lyophilized powder using less quantity of diluents and culture medium, minimizing the costs and reducing the time of analysis.
The objective will be achieved using the microbiological method by turbidimetry.
Water was used as the diluent to prepare the vancomycin solution. BHI broth as used as culture media for the growth of the S. aureus ATCC 25923. The method was linear in the range of 30, 39 and 50.7 µg/mL. It was selective, with vancomycin reference and sample absorbance values very similar. The precision of the method was proved at intraday (RSD 4.42 %), interday (RSD 3.56 %) and intermediate levels (RSD 2.03%). It was accurate with mean recovery of 100.71 % and robust when changes were performed in three parameters of the method and analyzed by the F-Test and t-Test.
The method for evaluating the potency of vancomycin in pharmaceutical product was successfully developed and validated.
The method can be applied to routine quality control of vancomycin product as an alternative that contemplates the green analytical chemistry and the current pharmaceutical analyzes.
The method can be applied to routine quality control of vancomycin product as an alternative that contemplates the green analytical chemistry and the current pharmaceutical analyzes.
Glyphosate and glufosinate are broad-spectrum herbicides which are frequently used in palm oil plantations for weed control. Metabolites of these herbicides are known to have environmental and food safety implications. As there is no validated method for multiresidue testing of these herbicides and their metabolites in palm oil products, a new method was needed for the purpose of regulatory analysis.
In this study, we endeavored to develop a rapid method for multiresidue analysis of glyphosate (+aminomethylphosphonic acid) and glufosinate (+3-methylphosphinicopropionic acid and N-acetyl-glufosinate) in refined and crude palm oil matrices using liquid chromatography (LC) tandem mass spectrometry (MS/MS).
The optimized sample preparation workflow included extraction of refined or crude palm oil (10 g) with acidified water (0.1 M HCl), cleanup by phase separation with dichloromethane, and analysis by LC-MS/MS with multiple reaction monitoring.
The use of a Torus-DEA LC column ensured simultaneous analysis of these compounds within a runtime of 10 min.
