Hydrogen oxidation soil bioassay using the single laboratory method

1986 ◽  
Vol 36 (1) ◽  
pp. 384-391
Author(s):  
R. D. Rogers ◽  
P. A. Pryfogle
2019 ◽  
Vol 32 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Juliana P. S. Mol ◽  
Andressa C. B. Guedes ◽  
Camila Eckstein ◽  
Amanda P. N. Quintal ◽  
Tayse D. Souza ◽  
...  

Canine brucellosis is an infectious and contagious disease associated with reproductive losses in breeding kennels. As a zoonotic disease, it poses a risk to human health, especially for veterinarians and breeders who handle materials potentially contaminated with Brucella canis. However, canine brucellosis is a neglected and underestimated disease given the difficulties in establishing a definitive diagnosis. We evaluated the frequency of detection of B. canis in 5 breeding kennels by using various serologic methods and PCR. Circulation of B. canis in these kennels was confirmed by bacterial isolation. The frequency of positive serologic results varied from 6.3% by AGID to 16.5% by dot-ELISA. There was no positive serology for smooth Brucella. PCR testing was positive in 13.9% of samples. The only detection tests with reasonable agreement were PCR and 2ME-MAT. The diagnosis of canine brucellosis remains challenging. The use of a single laboratory method, or even the use of different laboratory methods, may not be sufficient to reach a definitive diagnosis.


Author(s):  
Ugo Bussy ◽  
Gregory Hewitt ◽  
Yusuf Olanrewaju ◽  
Brian R May ◽  
Nicholas Anderson ◽  
...  

Abstract Background Flavanols and procyanidins are complex bioactives found in many foods such as cocoa. As their consumption is associated with health benefits, cocoa flavanols and procyanidins are receiving increasing attention from consumers, industry, researchers, and regulators. Objective The objective of this study is to validate a method using hydrophilic interaction chromatography (HILIC) with fluorescence detection (FLD) and a commercially available reference material for the determination of flavanols and procyanidins (CF) in cocoa-based products. Methods Method performances were evaluated for cocoa matrices with CF content that ranged from 0.8 to 500 mg/g, which included low CF matrices (milk and dark chocolate, cocoa powder, and liquor) and high CF matrices (cocoa extract and dietary supplement products). The method was validated in a single-laboratory by determining sensitivity, selectivity, linearity, stability, robustness, accuracy, and precision for each of the matrices. Results The method was validated for cocoa matrices with CF content that ranged from 0.8 to 500 mg/g. Accuracy ranged from 86 to 99% and repeatability (RSDr) from 1.5 to 8.6% for CF. Conclusions Analytical performances acquired through this single-laboratory validation study for a wide range of cocoa-based matrices demonstrate that this method is fit-for-purpose for the determination of flavanols and procyanidins in cocoa-based products. Highlights Hydrophilic interaction chromatography (HILIC) with fluorescence detection was successfully used to determine total CF content in multiple product types. Single-laboratory method validation results demonstrate that the method is fit for purpose for cocoa-based matrices containing <0.8 to 500 mg/g of CF.


2008 ◽  
Vol 91 (3) ◽  
pp. 598-606 ◽  
Author(s):  
Hamide Z Senyuva ◽  
Sureyya Ozcan ◽  
Dilek Cimen ◽  
John Gilbert

Abstract A single-laboratory method validation was conducted to establish the effectiveness of an immunoaffinity column cleanup procedure followed by liquid chromatography/mass spectrometry (LC/MS) for the determination of fumonisins B1 and B2 (FB1+ FB2) in corn. The test portion is extracted with acetonitrilemethanolwater (25 + 25 + 50). The extract is filtered, diluted with phosphate-buffered saline solution, and applied to an immunoaffinity column. FB1 + FB2 are removed with methanol and directly determined by reversed-phase LC with MS detection using selected-ion monitoring of 2 characteristic ions in each case. Test portions of blank corn samples were spiked with a mixture of FB1 + FB2 to give total levels of 200 and 500 ng/g, respectively. Recoveries of both FB1 and FB2 from spiked samples averaged 90.4101. Based on results for spiked raw corn (triplicates at 2 levels), the relative standard deviation for repeatability ranged from 2.8 to 7.1. The accuracy of the method was demonstrated by analysis of Food Analysis Performance Assessment Scheme (FAPAS) test material. The method was also applied to a small survey of processed corn products such as corn chips, cornflakes, and popcorn.


2008 ◽  
Vol 91 (6) ◽  
pp. 1402-1408 ◽  
Author(s):  
Taro Murakami ◽  
Tetsuo Yamano ◽  
Akihiko Nakama ◽  
Yoshiaki Mori

Abstract Single-laboratory method performance parameters were evaluated for analysis of biotin in total diet samples by hydrolyzed extraction and microbiological assay with Lactobacillus plantarum. The method was shown to be accurate, repeatable, rugged, and applicable for the determination of biotin in a broad range of matrixes and concentrations of total diet samples. The measurement uncertainty was evaluated with all food sample groups by combining the relative uncertainty of precision, recovery from each food group, and interday variation factors calculated from the ruggedness test results. The estimated daily intake of biotin in Osaka city and its expanded measurement uncertainty were 70.1 11.2 g/day. The value was 1.6 times higher than the current adequate intake of biotin in Japan.


The Analyst ◽  
2020 ◽  
Vol 145 (1) ◽  
pp. 122-131 ◽  
Author(s):  
Wanda V. Fernandez ◽  
Rocío T. Tosello ◽  
José L. Fernández

Gas diffusion electrodes based on nanoporous alumina membranes electrocatalyze hydrogen oxidation at high diffusion-limiting current densities with fast response times.


2016 ◽  
Vol 3 (1) ◽  
pp. 55-60
Author(s):  
Yu. Lavrynenko ◽  
R. Vozhegova ◽  
O. Hozh

The purpose of the research is to identify effi cient microfertilizers and growth stimulants considering biologi- cal features of new corn hybrids of different FAO groups under irrigation conditions in the South of Ukraine and trace their impact on grain productivity of the plants. The methods of the research are the fi eld method – to study the interaction of the research object with experimental factors of the natural environment, to register the yield and evaluate the biometrical indices; the laboratory method – to measure soil moisture, grain moisture content and grain quality indices; the statistical method – to evaluate the reliability of the obtained results; the calculation methods – for economic and energetic assessment of the growing techniques used. The results of the research. The paper defi nes the impact of microfertilizers and growth stimulants on the yield and grain quality of the corn hybrids of different maturity groups and on the economic effi ciency of growing them. The conclusions of the research. Under irrigation conditions of the Southern Steppe of Ukraine it is recommended that the following hybrids should be grown in dark-chestnut soils: early maturity DN Pyvykha, medium-early Skadovskyi, medium maturity Kakhovskyi and medium-late Arabat, using the growth stimulants – treating the seeds with Sezam-Nano and fertilizing with Grainactive at the stage of 7–8 leaves.


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