DETERMINATION OF TRACE ELEMENTS IN SOME BRANDS OF GREEN TEA USING WET DIGESTION, INFUSION AND DRY ASHING METHODS

2021 ◽  
Vol 4 (4) ◽  
pp. 520-525
Author(s):  
Ibrahim Imrana ◽  
Salisu Aminu ◽  
Umar Bilal ◽  
Bello Sada Mujitafa
Keyword(s):  
Trace Elements ◽  
Green Tea ◽  
Soil Conditions ◽  
Acid Digestion ◽  
Wet Digestion ◽  
Contributory Factors ◽  
Water Infusion ◽  
Dry Ashing ◽  
Almost All

The concentrations of trace elements (Cu, Zn, Fe, Mn and Ni) in some commercially available brands of green tea sold within Katsina metropolis coded (SGT, HGT, LGT, AGT and GGT) were determined using wet acid digestion, water infusion, and Dry Ashing methods by Atomic Absorption Spectroscopy (AAS).  Among the trace elements analyzed Nickel and Manganese recorded the highest value ranged 1.0 – 3.5 mg kg-1 and1.0 – 5.5 mg kg-1 in dry ashing and wet digestion respectively. Fortunately, almost all the elements analyzed were within the standard permissible limit of WHO. The content of trace elements was found highest in the Dry Ashing method and lowest values recorded in tea infusion. The contributory factors responsible for the differences found in tea samples could be from a varying concentration of metals in the soil, conditions of cultivation and preparations, and these vary between both countries of origin and for the type of tea. Further work is recommended on these brands to study other important parameters

Adaptation of a Dry Ashing Procedure for Determination of Selenium by Fluorimetry in High-Fat Foods

1995 ◽  
Vol 78 (2) ◽  
pp. 477-479 ◽  
Author(s):  
Jacques R Bellanger
Keyword(s):  
Magnesium Nitrate ◽  
High Fat ◽  
Fluorimetric Determination ◽  
Digestion Method ◽  
Wet Digestion ◽  
Dry Ashing ◽  
Selenium Determination ◽  
Wet Ashing ◽  
Total Procedure

Abstract The wet ashing–dry ashing procedure for destruction of organic matter in high-fat foods for subsequent fluorimetric determination of selenium was investigated. Samples were decomposed by predigestion with nitric acid and dry-ashed with magnesium nitrate and hydrochloric acid. Selenium was recovered quantitatively through the total procedure. Detection limit was about 4 ppb. Accuracy was tested by analysis of several reference materials and by comparison with the wet-digestion method. The present method can be used conveniently for selenium determination in high-fat foods.

Comparative Research of Two Pretreatment Methods on Determination of Trace Manganese in Panax Pseudo-Ginseng Var. Notoginseng by Atomic Absorption Spectroscopy

2012 ◽  
Vol 554-556 ◽  
pp. 2064-2067
Author(s):  
Jin Yang ◽  
Wei Liu ◽  
Bao Sheng Wang ◽  
Qing Hua Li ◽  
Ping Yi ◽  
...  
Keyword(s):  
Atomic Absorption ◽  
Absorption Spectroscopy ◽  
Atomic Absorption Spectroscopy ◽  
Recovery Rate ◽  
Comparative Research ◽  
Manganese Content ◽  
Wet Digestion ◽  
Dry Ashing ◽  
Better Than

In this research the atomic absorption spectroscopy method (the correlation coefficient was 0.9995) was employed for determination of the content of heavy metal-manganese in panax pseudo-ginseng var. notoginseng, which was chosen as the sample. The optimum conditions of two pretreatments were researched independently. In the dry ashing, the optimized temperature and time are 600°C and 4~6 hours respectively, and the manganese content determined is 53.16 ug/g and the recovery rate of manganese added in sample is 98.64%. In the wet digestion, The HNO3-H2O2 digestion system is the best one, and the content was 52.95ug/g and the recovery rate is 97.30%. So the two pretreatment methods of the sample are accurate enough on manganese content determination. But the dry ashing is better than the wet digestion relatively.

Comparison of Wet Ashing and Dry Ashing for the Determination of Arsenic in Marine Organisms, Using Methylated Arsenicals for Standards

1974 ◽  
Vol 57 (6) ◽  
pp. 1363-1365 ◽  
Author(s):  
John F Uthe ◽  
Harry C Freeman ◽  
John R Johnston ◽  
Paula Michalik
Keyword(s):  
Total Arsenic ◽  
Acid Digestion ◽  
Fish Tissues ◽  
Digestion Procedure ◽  
Dry Ashing ◽  
Nitric Acid Digestion ◽  
Wet Ashing ◽  
The Difference ◽  
Fish And Shellfish

Abstract A vanadium catalyzed pentoxide-sulfuric acid-nitric acid digestion procedure is described which gave higher values for total arsenic than the AOAC dry ash procedure with fish and shellfish tissue. Recoveries of added methylarsenic compounds were also lower by dry ashing procedures but essentially complete by the new ashing procedure. Arsenic levels in a variety of shellfish and fish tissues as determined by wet ashing averaged 6.3% higher than dry ash values. In lobster hepatopancreas the difference was 13.1% for a large number of samples from a number of sampling areas.

Determination of Trace Elements in Water by Inductively Coupled Plasma–Mass Spectrometry: Collaborative Study

1994 ◽  
Vol 77 (4) ◽  
pp. 1004-1023 ◽  
Author(s):  
J E Longbottom ◽  
T D Martin ◽  
K W Edgell ◽  
S E Long ◽  
M R Plantz ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Trace Elements ◽  
Inductively Coupled Plasma ◽  
Acid Digestion ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Relative Standard ◽  
Nitric Acid Digestion ◽  
Plasma Mass Spectrometry

Abstract A joint U.S. Environmental Protection Agency (U.S. EPA)—AOAC interlaboratory method validation study was conducted on U.S. EPA method 200.8, Determination of Trace Elements in Waters and Wastes by Inductively Coupled Plasma–Mass Spectrometry. The purpose of the study was to determine and compare the mean recovery and precision of the inductively coupled plasma–mass spectrometry (ICP–MS) analyses for 20 trace elements in reagent water, drinking water, and groundwater. The formal study was based on Youden’s nonreplicate plan for collaborative tests of analytical methods. The test waters were spiked with the 20 trace elements at 6 concentration levels in the 0.8–200 μg/L range, prepared as 3 Youden pairs. Thirteen collaborators spiked 100 mL aliquots of the test waters, acidified them with 1 mL concentrated HNO3 and 0.5 mL concentrated HCl, reduced the volume to 20 mL by heating in an open beaker at 85°C, refluxed them for 30 min at 95°C, and diluted them to 50 mL. After centrifuging or settling the samples, a 20 mL portion of the supernatant was diluted to 50 mL and analyzed by ICP–MS. Related experiments evaluated the method performance in wastewater and wastewater digestate at a single concentration pair, and an alternative nitric acid digestion procedure. Mean recoveries for reagent water, drinking water, and groundwater were generally 95–105% with between-laboratory relative standard deviations about 4–8%. The method also worked well with wastewaters and digestate, with between-laboratory relative standard deviations averaging 8% and recoveries averaging 100%. Recoveries of silver, however, were low in all matrixes at concentrations over 100 μg/L. The nitric acid digestion procedure was comparable in accuracy and precision to the mixed-acid digestion in U.S. EPA method 200.8. The method was adopted first action by AOAC INTERNATIONAL.

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