scholarly journals Studies on Formation and Thermal Decomposition of Lead Hydride, PbH4

2010 ◽  
Vol 1 (2) ◽  
pp. 111-119
Author(s):  
Narsito Narsito
Keyword(s):  
Thermal Decomposition ◽  
Atomic Absorption ◽  
Acidic Solution ◽  
Sodium Tetrahydroborate ◽  
Hydride Generation ◽  
Spectrometric Analysis ◽  
Gas Flows ◽  
On Line ◽  
Atomic Absorption Spectrometric

In the present work, some fundamental aspects of the formation of gaseous lead hydride from aqueous solutions containing divalent lead ions (Pb2+) and its application in the atomic absorption spectrometric analysis lead has been investigated. By utilizing a peristaltic pump, an acidic solution of Pb2+ was first oxidized with ammonium peroxodisulphate, NH4S2O8, and followed by reduction with sodium tetrahydroborate, NaBH4. After a gas-liquid separation, the gaseous lead hydride produced was directly swept into an electrically heated open ended quartz tube, located at the light path of an atomic absorption spectrometer in order to have possibilities for specific atomic absorption spectroscopic measurements. The absorbance signals caused by lead atomic absorption could be used proportionally to estimate the density of atomic lead vapor produced in the thermal decomposition under investigation. Results showed that on-line pre-oxidation of the analyte is very important and crucial step in the gaseous hydride generation of lead, and no lead hydride was produced without the involvement of this step. Moreover, it was observed that the use of low major gas flows cannot be applied in quantitative atomic absorption spectrometric determination of lead by this technique. This condition may result in possible losses of the analyte atomic vapor due to metallic condensation.

Flow injection hydride generation electrothermal atomic absorption spectrometric determination of toxicologically relevant arsenic in urine

Talanta ◽  
2006 ◽  
Vol 69 (5) ◽  
pp. 1112-1117 ◽  
Author(s):  
Panayot K. Petrov ◽  
Ivan Serafimovski ◽  
Trajce Stafilov ◽  
Dimiter L. Tsalev
Keyword(s):  
Atomic Absorption ◽  
Flow Injection ◽  
Hydride Generation ◽  
Atomic Absorption Spectrometric

Electrothermal Atomic Absorption Spectrometric Determination of Selenium in Foods and Diets

1983 ◽  
Vol 66 (5) ◽  
pp. 1129-1135 ◽  
Author(s):  
Jorma Kumpulainen ◽  
Anna-Maria Raittila ◽  
Jari Lehto ◽  
Pekka Koivistoinen
Keyword(s):  
Atomic Absorption ◽  
Collaborative Study ◽  
Hydride Generation ◽  
Bovine Liver ◽  
Pyrrolidine Dithiocarbamate ◽  
Matrix Modifier ◽  
Organic Extraction ◽  
The Mean ◽  
Atomic Absorption Spectrometric

Abstract The validity of 2 electrothermal atomic absorption spectrometric methods for determination of selenium in foods and diets was tested. By using 0.5% Ni(II) as a matrix modifier to prevent selenium losses during the ashing step, it was shown that selenium can be determined in samples containing ≥1 μg Se/g dry wt without organic extraction. The mean recovery tested, using NBS Bovine Liver, was 98%; recovery of added inorganic selenium in Bovine Liver matrix was 100%. In addition, this method gave values closest to the median value of all participating laboratories using hydride generation AAS or the spectrof luorometric method in a collaborative study on high selenium wheat, flour, and toast samples. For samples with concentrations <1 μg Se/g dry wt, separation of selenium from interfering Fe and P ions by organic extraction was necessary. Using inorganic ,5 Se in meat and human milk matrixes, an ammonium pyrrolidine dithiocarbamate-methyl isobutyl ketone- extraction system with added Cu(II) as a matrix modifier yielded the best extraction recoveries, 97 and %%, respectively. Accuracy and precision of the method were tested using several official and unofficial biological standard materials. The mean accuracy was within 4% of the certified or best values of the standard materials and the day-to-day variation was 9%. The Se/Fe or Se/P interference limits proved to be low enough not to affect selenium determinations in practically all foods or diets. The practical detection limit of the method was 3 ng Se/g dry wt for 1.0 g dry wt samples. Approximately 20 duplicate determinations can be performed per day. In terms of sensitivity, accuracy, precision, and sample throughput, the tested method compares favorably with the best methods available.

Dry Ashing, Hydride Generation Atomic Absorption Spectrometric Determination of Arsenic and Selenium in Foods

1982 ◽  
Vol 65 (3) ◽  
pp. 647-650 ◽  
Author(s):  
Gerard K H Tam ◽  
Gladys Lacroix
Keyword(s):  
Detection Limit ◽  
Atomic Absorption ◽  
Reference Materials ◽  
Hydride Generation ◽  
Spectrometric Method ◽  
Flameless Atomic Absorption ◽  
Dry Ashing ◽  
Atomic Absorption Spectrometric ◽  
Certified Values

Abstract A dry ashing, flameless atomic absorption spectrometric method was evaluated to determine arsenic and selenium in foods. Samples were dry-ashed with Mg(N03)2-MgO and dissolved in HC1. Selenate was reduced to selenite by boiling in 4N HC1, and arsenate to arsenite by treatment with KI. Hydrides of arsenic and selenium were generated by the addition of NaBH4 and were swept by nitrogen and hydrogen into a thermally heated silicate tube furnace. The detection limit was about 5 ppb for each element based on a 10 g sample. Analytical results obtained for several samples of NBS reference materials agreed with the certified values. The procedure was evaluated by another laboratory and results were satisfactory.

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