scholarly journals Determination of the Iodine Content of Some Commonly Consumed Foods in Zaria Metropolis, Nigeria, Using PCNAA and Sandell-Kolthoff Reaction

2014 ◽  
Vol 2014 ◽  
pp. 1-4
Author(s):  
T. Muhammad ◽  
A. Uzairu ◽  
M. S. Sallau ◽  
M. O. A. Oladipo
Keyword(s):  
Neutron Activation Analysis ◽  
Standard Deviation ◽  
Test Score ◽  
Research Reactor ◽  
Iodine Content ◽  
Food Samples ◽  
Average Percentage ◽  
Average Percentage Deviation ◽  
Percentage Standard Deviation

The Nigerian Research Reactor-1 was employed in the analysis of iodine in local food samples at an operating flux of 5.0×1011 ncm−2 s−1. Preconcentration neutron activation analysis (PCNAA) was compared against the most common spectroscopic (Sandell-Kolthoff reaction) technique, giving a concentration range of 0.295 to 2.960 mg/Kg and 0.264 to 2.725 mg/Kg, respectively, with an average percentage deviation of 11.34% and a positive correlation between the methods at 0.89. PCNAA and Sandell-Kolthoff spectroscopy of NIST 1548a reported values of 0.759±0.06 mg/Kg and 0.751±0.05 with Student’s t-test score of 1 and 0.95 and percentage standard deviation of 0 and 1.12%, respectively.

scholarly journals Determination of trace elements in some fruits collected in Vietnam and Korea by Neutron Activation Analysis on Dalat and HANARO research reactors

2015 ◽  
Vol 5 (4) ◽  
pp. 23-29
Author(s):  
Thi Sy Nguyen ◽  
Manh Dung Ho ◽  
Van Doanh Ho ◽  
Quang Thien Tran ◽  
Sam Chung Yong
Keyword(s):  
Trace Elements ◽  
Neutron Activation Analysis ◽  
Activation Analysis ◽  
Neutron Activation ◽  
Research Reactor ◽  
Standard Samples ◽  
Long Time ◽  
Polyethylene Bags ◽  
Mn Concentrations

The k0-based neutron activation analysis (k0-NAA) has been applied for determination of trace multi-element in 5 fruits: Orange, tomato, persimmon, pear and apple. The samples were collected in Vietnam and Korea, and dried-frozen in laboratory at a temperature of -650C, weighed approximately 50 mg or 100 mg each sample, and put in clean polyethylene bags for short and long time irradiations, respectively. The NIST-1547 (Peach Leaves) and IAEA-V-10 (Hay Powder) were used for the purpose of quality control. Both analytical and standard samples were irradiated in the 500 kW Dalat research reactor (Vietnam) and the 20 MW HANARO research reactor (Korea). Concentration of 16 elements: Al, As, Au, Br, Ca, Cl, Co, Eu, Fe, K, La, Mg, Mn, Na, Rb and Zn were determined. By comparison the concentrations of trace elements in the investigated Vietnam and Korea’s fruits, revealed that they are mostly similar between two places. However, the Ca concentration in orange from Vietnam was approximately 2.5 times higher than that one from Korea, whereas the Ca concentration in pear from Vietnam was approximately 21 times lower than that one from Korea. The Mn concentrations in all of fruits that collected in Vietnam were mostly higher than those collected in Korea, ranging between 1.4 to 2.2 times.

Fluorometric Determination of Selenium in Foods

1974 ◽  
Vol 57 (2) ◽  
pp. 368-372 ◽  
Author(s):  
Milan Ihnat
Keyword(s):  
Standard Deviation ◽  
Milk Powder ◽  
Skim Milk ◽  
Skim Milk Powder ◽  
Food Samples ◽  
Fluorometric Method ◽  
Fluorometric Determination ◽  
Relative Standard ◽  
The Mean

Abstract A fluorometric method using 2,3-diaminonaphthalene for estimating selenium has been evaluated with regard to its applicability to food samples. Charring of the sample during digestion appeared to result in losses of native and added selenium from some samples, so a modified wet digestion procedure was introduced. Digestion first in nitric acid followed by a mixture of nitric-perchloric-sulfuric acids substantially reduced the incidence of sample charring for a variety of foods. The mean apparent recovery of selenium added as selenite or selenate at 100 and 500 ng levels to 0.1 and 1.0 g corn cereal, skim milk powder, and meat and 0.1 g fish was 101.0%; the actual recovery of the same levels of selenium from standard solutions was 96.6%. For a variety of samples containing 5—750 ng native or added selenium, the standard deviation as 4.7 + 1.95 X 10-2W ng, where W = ng selenium in the sample taken for analysis. The relative standard deviation (RSD) as a function of selenium weight (ng) was 50% (10), 6.7% (100), 4.3% (200), 3.1% (400), 2.7% (600), and 2.5% (800). The detection limit (weight of selenium at which RSD = 50%) was 10 ng at a mean blank level of 25 ng.

scholarly journals Aqueous Two-Phase Systems: A New Approach for the Determination of Brilliant Blue FCF in Water and Food Samples

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Sabah Shiri ◽  
Tahere Khezeli ◽  
Shahram Lotfi ◽  
Sina Shiri
Keyword(s):  
Polyethylene Glycol ◽  
Standard Deviation ◽  
Food Samples ◽  
Brilliant Blue ◽  
Phase System ◽  
Optimum Conditions ◽  
Two Phase ◽  
Brilliant Blue Fcf ◽  
Relative Standard

A novel, simple, and more sensitive spectrophotometric procedure has been developed for the determination of brilliant blue FCF in water and food samples by an aqueous two-phase system (ATPS). In this method, adequate amount of polyethylene glycol/ sodium carbonate (PEG-4000/Na2CO3) was added to aqueous solution for formation of a homogeneous solution. To the mixture solution, suitable amount ofNa2CO3was added, the mixture solution was shaken until the salt was dissolved, and then it was separated into two clear phases easily and rapidly. The target analyte in the water sample was extracted into the polyethylene glycol phase. After extraction, measuring the absorbance at 634 nm was done. The effects of different parameters such as polyethylene glycol (type and concentration), pH, salt (type and amount), centrifuge time, and temperature on the ATPS of dye was investigated and optimum conditions were established. Linear calibration curves were obtained in the range of 0.25–750 ng/mL for brilliant blue FCF under optimum conditions. Detection limit based on three times the standard deviation of the blank (3Sb) was 0.12 ng/mL. The relative standard deviation (RSD) for 400 ng/mL was 3.14%. The method was successfully applied to the determination of brilliant blue FCF in spiked samples with satisfactory results. The relative recovery was between 96.0 and 102.2%.

scholarly journals Determination of Methylcellulose and Hydroxypropyl Methylcellulose Food Gums in Food and Food Products: Collaborative Study

2007 ◽  
Vol 90 (3) ◽  
pp. 786-793 ◽  
Author(s):  
Robert G Harfmann ◽  
Balasaheb K Deshmukh ◽  
Jerry Conklin ◽  
Maciej Turowski ◽  
Stephanie Lynch ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Hydroxypropyl Methylcellulose ◽  
Collaborative Study ◽  
Food Samples ◽  
Size Exclusion ◽  
Official Method ◽  
Relative Standard ◽  
Aoac Official

Abstract A collaborative study was performed to determine the reproducibility of a method for the determination of methylcellulose (MC) and hydroxypropyl methylcellulose (HPMC) in food. These widely used food gums possess unusual solubility characteristics and cannot accurately be determined by existing dietary fiber methods. The new method uses the enzyme-digestion procedure of AOAC Official Method 991.43. Digestate solutions must be refrigerated to fully hydrate MC or HPMC. The chilled solutions are filtered and analyzed by size-exclusion liquid chromatography. Collaborating laboratories received 28 samples containing MC or HPMC in the range of 0100%. The sample set included blind duplicates of 5 food matrixes (bread, milk, fish, potato, and powdered juice drink). Cochran and Grubbs tests were used to eliminate outliers. For food samples containing MC, values for within-laboratory precision, repeatability relative standard deviation (RSDr), ranged from 4.2 to 16%, and values for among-laboratories precision, reproducibility relative standard deviation (RSDR), ranged from 11 to 20%. For HPMC samples, RSDr values ranged from 6.4 to 27%, and RSDR values ranged from 17 to 39%. Recoveries of MC and HPMC from the food matrixes ranged from 78 to 101%. These results show acceptable precision and reproducibility for the determination of MC and HPMC, for which no Official AOAC Methods exist. It is recommended that this method be adopted as AOAC Official First Action.

scholarly journals Rapid, Simple, and Sensitive Spectrofluorimetric Method for the Estimation of Ganciclovir in Bulk and Pharmaceutical Formulations

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Garima Balwani ◽  
Emil Joseph ◽  
Satish Reddi ◽  
Vibhu Nagpal ◽  
Ranendra N. Saha
Keyword(s):  
Standard Deviation ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Calibration Graph ◽  
Limit Of Quantification ◽  
Average Percentage ◽  
Ich Guidelines ◽  
Spectrofluorimetric Method ◽  
Relative Standard

A new, simple, rapid, sensitive, accurate, and affordable spectrofluorimetric method was developed and validated for the estimation of ganciclovir in bulk as well as in marketed formulations. The method was based on measuring the native fluorescence of ganciclovir in 0.2 M hydrochloric acid buffer of pH 1.2 at 374 nm after excitation at 257 nm. The calibration graph was found to be rectilinear in the concentration range of 0.25–2.00 μg mL−1. The limit of quantification and limit of detection were found to be 0.029 μg mL−1and 0.010μg mL−1, respectively. The method was fully validated for various parameters according to ICH guidelines. The results demonstrated that the procedure is accurate, precise, and reproducible (relative standard deviation <2%) and can be successfully applied for the determination of ganciclovir in its commercial capsules with average percentage recovery of 101.31 ± 0.90.

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