Comparison of Manual and Benzenesulfonyl Chloride-Semiautomated Thiochrome Methods for Determination of Thiamine in Foods

1981 ◽  
Vol 64 (3) ◽  
pp. 616-622
Author(s):  
Abdel-Gawad M Soliman
Keyword(s):  
Matrix Effects ◽  
Linear Regression Analysis ◽  
Food Products ◽  
Benzenesulfonyl Chloride ◽  
Sample Matrix ◽  
Sample Extract ◽  
Before And After ◽  
Aoac Method ◽  
Reproducible Method ◽  
Manual Methods

Abstract A semiautomated procedure was used to measure the fluorescence of sample extracts before and after the addition of benzenesulfonyl chloride (BSC). Addition of BSC inhibited thiochrome formation and provided a more representative blank based on the fluorescence of all the reactants except thiochrome. Thiamine standard was added to each sample extract so that thiamine concentration could be calculated after correcting for sample matrix effects on thiochrome fluorescence. Twenty food products were analyzed using this method, and the results were compared with those obtained using the manual AOAC method. The mean percent recoveries and standard deviations were 100.2 ± 5.3 and 101.1 ± 10.1 for the BSC-semiautomated and the AOAC manual methods, respectively. Replicate analyses using the BSC method gave an average coefficient of variation of 2.8%. Linear regression analysis showed that the BSC method gave higher values, with a mean increase of 14.8%, than those obtained using the manual method. Sixty-four percent of this difference was due to elimination of the column purification step and 36% was due to correcting for sample matrix effects on thiochrome and blank fluorescence. The BSC method provides a rapid, accurate, and reproducible method for thiamine assay in different food products, especially for those foods with low thiamine levels.

Analysis of variations in and correlations between selected physical parameters of common beech (Fagus silvatica L.) nuts

2017 ◽  
Vol 1 (21) ◽  
pp. 49-63
Author(s):  
Zdzisław Kaliniewicz ◽  
Piotr Markowski ◽  
Andrzej Anders ◽  
Paweł Tylek ◽  
Zbigniew Krzysiak ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Correlation Analysis ◽  
Cross Sections ◽  
Linear Regression Analysis ◽  
Physical Parameters ◽  
Common Beech ◽  
Mesh Screen ◽  
Before And After ◽  
Fagus Silvatica ◽  
Highly Correlated

The basic dimensions and the mass of common beech nuts and seeds from five nut batches, harvested from tree stands in northern Poland, were determined. Environmental conditions had a greater influence on seed plumpness than the age of tree stands. The results of measurements were analyzed statistically by analysis of variance, correlation analysis and linear regression analysis. Despite differences in their plumpness, nuts were characterized by nearly identical cross-sections which resembled an equilateral triangle. The thickness of nuts and seeds was highly correlated with their mass, and this information can facilitate seed husking and separation into mass categories. Before and after husking, seeds should be separated with the use of a mesh screen with longitudinal openings. Medium-sized (most numerous) seeds were separated into the following plumpness categories using a screen separator with ≠6 mm and ≠7 mm openings: 84% of moderately plump seeds, 3% of seeds with reduced plumpness, and 13% of plump seeds.

scholarly journals PEMERIKSAAN KANDUNGAN ZAT KIMIA FORMALIN PADA BAKSO IKAN DAN TAHU

2020 ◽  
Vol 5 (1) ◽  
pp. 81
Author(s):  
Tuti Handayani ◽  
Sherly Mutiara
Keyword(s):  
Health Education ◽  
Qualitative Analysis ◽  
Experimental Method ◽  
Chemical Compound ◽  
Food Additives ◽  
Food Products ◽  
Analysis Approach ◽  
Toxic Chemical ◽  
Protein Sources ◽  
Before And After

<p><em>Formaldehyde a toxic chemical compound. Formaldehyde is prohibited for use in food according to the RI Minister of Health Regulation No.033 of 2012 concerning food additives. Meatballs, Fish and Tofu are protein sources of food. This material is easily damaged by microorganisms. There have been many cases of formaldehyde found in food products in Indonesia. The purpose of this study was to determine the presence or absence of formaldehyde in fish, meatball and tofu before and after providing health education. the method used in this study is an experimental method using a Qualitative Analysis approach. The results obtained were found 16  samples (fish and dry fish) is positive of formaldehyde. after providing education to traders the 15 samples still found in the market. That means counselling is not effective as an effort to eliminate formaldehyde in food products.</em></p>

scholarly journals Cannabinoids in Exhaled Breath following Controlled Administration of Smoked Cannabis

2013 ◽  
Vol 59 (12) ◽  
pp. 1780-1789 ◽  
Author(s):  
Sarah K Himes ◽  
Karl B Scheidweiler ◽  
Olof Beck ◽  
David A Gorelick ◽  
Nathalie A Desrosiers ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Time Course ◽  
Matrix Effects ◽  
Solid Phase ◽  
Driving Under The Influence ◽  
Phase Extraction ◽  
Exhaled Breath ◽  
C Storage ◽  
Before And After ◽  
Occasional Smoker

BACKGROUND Δ9-Tetrahydrocannabinol (THC), 11-nor-9-carboxy-THC (THCCOOH), and cannabinol (CBN) were measured in breath following controlled cannabis smoking to characterize the time course and windows of detection of breath cannabinoids. METHODS Exhaled breath was collected from chronic (≥4 times per week) and occasional (&lt;twice per week) smokers before and after smoking a 6.8% THC cigarette. Sample analysis included methanol extraction from breath pads, solid-phase extraction, and liquid chromatography–tandem mass spectrometry quantification. RESULTS THC was the major cannabinoid in breath; no sample contained THCCOOH and only 1 contained CBN. Among chronic smokers (n = 13), all breath samples were positive for THC at 0.89 h, 76.9% at 1.38 h, and 53.8% at 2.38 h, and only 1 sample was positive at 4.2 h after smoking. Among occasional smokers (n = 11), 90.9% of breath samples were THC-positive at 0.95 h and 63.6% at 1.49 h. One occasional smoker had no detectable THC. Analyte recovery from breath pads by methanolic extraction was 84.2%–97.4%. Limits of quantification were 50 pg/pad for THC and CBN and 100 pg/pad for THCCOOH. Solid-phase extraction efficiency was 46.6%–52.1% (THC) and 76.3%–83.8% (THCCOOH, CBN). Matrix effects were −34.6% to 12.3%. Cannabinoids fortified onto breath pads were stable (≤18.2% concentration change) for 8 h at room temperature and −20°C storage for 6 months. CONCLUSIONS Breath may offer an alternative matrix for identifying recent driving under the influence of cannabis, but currently sensitivity is limited to a short detection window (0.5–2 h).

Microwave Oven Method for Rapid Determination of Moisture in Meat

1975 ◽  
Vol 58 (6) ◽  
pp. 1188-1193 ◽  
Author(s):  
Julio D Pettinati
Keyword(s):  
Rapid Determination ◽  
Linear Regression Analysis ◽  
Microwave Oven ◽  
Moisture Determination ◽  
Oven Method ◽  
Sources Of Variation ◽  
Aoac Method ◽  
Air Blower ◽  
Meat Samples

Abstract A new, rapid procedure was developed for moisture determination in meat. Results with the method were evaluated by comparative analysis with AOAC method 24.003(b). The new method is accurate, precise, and simple. Samples were prepared for drying by admixture with ferrous oxide and sodium chloride in glass weighing bottles and heating 2.5 mill in a domestic-type 1000 watt microwave oven. After heating, the residues were exposed 1 min in the stream of the oven chamber air blower, then covered and weighed. From comparative determinations on 67 meat samples containing from 3.5 to 77.9% moisture, meat type and moisture level were not significant (P = 0.05) sources of variation as determined by t-tests. Mean moisture content was 0.05% higher by the microwave oven method than by the AOAC method. Repeatability between duplicates was ± 0.47% moisture by microwave oven and ±0.45% by the AOAC method. Precision between paired determinations by the 2 methods was ±0.57% moisture. Both the t-test for significance (P = 0.05) and linear regression analysis of the comparative determinations indicated that the 2 methods were equivalent for determining moisture. Continued study of the method is recommended.

Evaluation of Urea-Acid System as Medium of Extraction for the B-Group Vitamins. Part II. Simplified Semi-Automated Chemical Analysis for Niacin and Niacinamide in Cereal Products

1983 ◽  
Vol 66 (2) ◽  
pp. 291-296
Author(s):  
Ram B Roy ◽  
John J Merten
Keyword(s):  
Chemical Analysis ◽  
Food Products ◽  
Extraction System ◽  
Acid Extraction ◽  
Acid System ◽  
Cereal Products ◽  
Analytical Results ◽  
Aoac Method

Abstract Efficiency of a urea-acid system was evaluated as medium of extraction for niacin and niacinamide from cereals and other selected food products. Samples were treated with IN HC1 in the presence of urea and autoclaved 30 min at 15 psi. Extracts were diluted to a known volume, filtered, and analyzed. The analytical results obtained for niacin were compared with values obtained by AOAC method 43.044. In general, the urea-acid extraction system was simple and straightforward with an efficiency comparable to the AOAC method. The analytical manifold designed uses fewer modules, gives net absorbance readings from sample and blank, and is capable of analyzing 50 samples per hour.

scholarly journals Involvement of NO in Antinociception of NSAIDS in Murine Formalin Hind Paw Assay

Drug Research ◽  
2020 ◽  
Vol 70 (04) ◽  
pp. 145-150 ◽  
Author(s):  
Viviana Noriega ◽  
Hugo F. Miranda ◽  
Juan Carlos Prieto ◽  
Ramón Sotomayor-Zárate ◽  
Fernando Sierralta
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Dose Response ◽  
Rank Order ◽  
Linear Regression Analysis ◽  
Second Phase ◽  
Response Curves ◽  
Before And After ◽  
Two Phases ◽  
Phase Phase

AbstractThere are different animal models to evaluate pain among them the formalin hind paw assay which is widely used since some of its events appear to be similar to the clinical pain of humans. The assay in which a dilute solution of formalin is injected into the dorsal hindpaw of a murine produces two ‘phases’ of pain behavior separated by a inactive period. The early phase (Phase I) is probably due to direct activation of nociceptors and the second phase (Phase II) is due to ongoing inflammatory input and central sensitization. Mice were used to determine the potency antinociceptive of piroxicam (1,3,10,and 30 mg/kg), parecoxib (0.3, 1,3,10 and 30 mg/kg), dexketoprofen (3,10,30 and 100 mg/kg) and ketoprofen (3,10,30 and 100 mg/kg). Dose-response for each NSAIDs were created before and after 5 mg/kg of L-NAME i.p. or 5 mg/kg i.p. of 7-nitroindazole. A least-squares linear regression analysis of the log dose–response curves allowed the calculation of the dose that produced 50% of antinociception (ED50) for each drug. The ED50 demonstrated the following rank order of potency, in the phase I: piroxicam > dexketoprofen > ketoprofen > parecoxib and in the phase II: piroxicam > ketoprofen > parecoxib > dexketoprofen. Pretreatment of the mice with L-NAME or 7-nitroindazol induced a significant increase of the analgesic power of the NSAIDs, with a significant reduction of the ED50. It is suggested that NO may be involved in both phases of the trial, which means that nitric oxide regulates the bioactivity of NSAIDs.

XRF Analysis by Combining the Standard Addition Method with Matrix-Correction Models

1982 ◽  
Vol 26 ◽  
pp. 395-400
Author(s):  
Peter B. De Groot
Keyword(s):  
Linear Regression Analysis ◽  
Standard Addition ◽  
Standard Addition Method ◽  
Correction Coefficient ◽  
Matrix Correction ◽  
Addition Method ◽  
Low Concentrations ◽  
Wide Range ◽  
Before And After ◽  
Single Standard

AbstractThe standard addition method is often useful for singleelement analyses in matrices of unknown composition or those difficult to reproduce. Results are good at low concentrations where concentration vs. intensity is approximately linear, but serious errors occur at higher concentrations. A method is shown here for greatly extending the range of the standard addition approach by combining it with with matrix correction models. Expressions incorporating the well-known alpha-or beta-correction coefficients are derived for the observed intensities before and after addition of the analyte. K-ratio measurements on the saraple plus a single standard addition allow the calculation of the correction coefficient and analyte concentration. Several standard addition levels can also be used and concentration obtained from non-linear regression analysis. A computer program has been developed to perform these calculations. Analyses of CuO on silica and of four metals in a metal oxide catalyst over a wide range of concentrations gave results with a relative accuracy generally within ±5%.

scholarly journals Quality of life of renal transplant donors

2017 ◽  
Vol 20 (2) ◽  
pp. 24-34
Author(s):  
Sagar Koirala ◽  
Pawan Raj Chalise ◽  
Prem Gyawali
Keyword(s):  
Quality Of Life ◽  
Renal Transplant ◽  
Short Form ◽  
Linear Regression Analysis ◽  
Bodily Pain ◽  
Donor Nephrectomy ◽  
High Rate ◽  
Multivariate Linear Regression Analysis ◽  
Before And After

Introduction: End stage renal disease has a high rate of mortality and morbidity. Kidney transplantation remains the best treatment option in comparison to other forms of renal replacement therapy. Live related donor renal transplantation was started at TUTH in 2008. Compared to other established centers, the outcome of transplantation was comparable. Though there is considerable evidence showing that donors are able to return to their healthy life, quality of life (QOL) assessment using standardized questionnaires has not yet been done in our centre. This study was carried out in order to compare QOL before and after donor nephrectomy. Methods: Short Form 36 version 2 (SF36v2) was used to assess the quality of life of kidney donors. Interview was conducted just before and three months after donor nephrectomy. Eight domains of quality of life score were compared using SPSS 17.0. Kolmogorov Smirnov test was used to check normal distribution of data. Mean scores before and after donation was compared with paired t test. Multivariate linear regression analysis was done to find out variables predicting poorer outcome. Results: Out of eight domains of quality of life, bodily pain, physical functioning and physical role limitation were decreased 3 months after donation. However, this did not have any impact on overall quality of life of donors. Increasing age was found to an independent predicter of poorer quality of life. However gender and donation status had no significance. Conclusion: Quality of life of renal transplant donors was not affected by donor nephrectomy. Long term follow up and quality of study is required in order to assess the changes in physical health component with time.

scholarly journals Automated Transport and Sorting System in a Large Reference Laboratory: Part 2. Implementation of the System and Performance Measures over Three Years

2002 ◽  
Vol 48 (10) ◽  
pp. 1761-1767 ◽  
Author(s):  
Charles D Hawker ◽  
William L Roberts ◽  
Susan B Garr ◽  
Leslie T Hamilton ◽  
John R Penrose ◽  
...  
Keyword(s):  
Performance Measures ◽  
Linear Regression Analysis ◽  
Turnaround Time ◽  
Automation System ◽  
Reference Laboratory ◽  
Before And After ◽  
And Performance ◽  
Sorting System ◽  
Automation Project ◽  
Project Objectives

Abstract Background: Our laboratory implemented a major automation system in November 1998. A related report describes a 4-year process of evaluation and planning leading to system installation. This report describes the implementation and performance results over 3 years since the system was placed into use. Methods: Project management software was used to track the project. Turnaround times of our top 500 tests before and after automation were measured. We compared the rate of hiring of employees and the billed unit per employee ratio before and after automation by use of linear regression analysis. Finally, we analyzed the financial contribution of the project through an analysis of return on investment. Results: Since implementation, the volume of work transported and sorted has grown to &gt;15 000 new tubes and &gt;25 000 total tubes per day. Median turnaround time has decreased by an estimated 7 h, and turnaround time at the 95th percentile has decreased by 12 h. Lost specimens have decreased by 58%. A comparison of pre- and post-implementation hiring rates of employees estimated a savings of 33.6 employees, whereas a similar comparison of ratios of billed units per employee estimated a savings of 49.1 employees. Using the higher figure, we estimated that the $4.02 million cost of the project would be paid off ∼4.9 years subsequent to placing the system into daily use. Conclusions: The overall automation project implemented in our laboratory has contributed considerably to improvement of key performance measures and has met our original project objectives.

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