Improved sample preparation for accurate determination of low concentrations of lead in whole blood by graphite furnace analysis

1991 ◽  
Vol 37 (4) ◽  
pp. 515-519 ◽  
Author(s):  
Beryl E Jacobson ◽  
Gillian Lockitch ◽  
Gayle Quigley

Abstract The effect of low concentrations of lead on pre- and post-natal growth and development is a current concern. We describe a simple method of sample preparation for direct determination of lead in whole blood by Zeeman graphite-furnace atomic absorption spectrometry. This procedure improves analytical precision and accuracy of lead determinations at low concentrations as compared with published furnace data. At blood lead concentrations of 0.25, 1.98, and 3.76 mumol/L, within-run CVs were 3.2%, 1.8%, and 1.4% respectively; between-run CVs were 7.3%, 2.9%, and 2.2%. Accuracy, as demonstrated by analytical recovery, ranged from 99% to 102%. Our reproducibility/accuracy score in the 1989 Quebec interlaboratory comparison program was 96% compared with the target, second best of 66 participating laboratories.

2011 ◽  
Vol 62 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Blanka Tariba ◽  
Alica Pizent ◽  
Zorana Kljaković-Gašpić

Determination of Lead in Croatian Wines by Graphite Furnace Atomic Absorption SpectrometryA method has been developed for direct determination of lead in wine by graphite furnace atomic absorption spectrometry (GFAAS) with Zeeman-effect background correction. The thermal behaviour of Pb during pyrolysis and atomisation stages was investigated without matrix modifier and in the presence of Pd(NO3)2, Pd(NO3)2+ Mg(NO3)2× 6H2O, and NH4H2PO4+ Mg(NO3)2× 6H2O as matrix modifiers. A simple 1:1 dilution of wine samples with Pd(NO3)2as a matrix modifier proved optimal for accurate determination of Pb in wine. Mean recoveries were 106 % for red and 114 % for white wine, and the detection limit was 3 μg L-1. Within-run precision of measurements for red and white wine was 2.1 % and 1.8 %, respectively. The proposed method was applied for analysis of 23 Croatian wines. Median Pb concentrations were 33 μg L-1, range (16 to 49) μg L-1in commercially available wines and 46 μg L-1, range (14 to 559) μg L-1in home-made wines. There were no statistically significant differences (P<0.05) in Pb concentration between commercial and home-made wines or between red and white wines.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Pamela S. M. Rocha ◽  
Graziela F. B. Cruz ◽  
Ricardo J. Cassella

The present work proposes a simple method for direct determination of Cu and Mn in commercial fruit juices and nectars by graphite furnace atomic absorption spectrometry (GF AAS). We analyzed samples of different flavors (orange, mango, passion fruit, peach, and grape) and brands of Brazilian commercial fruit juices and nectars. We also carried out a study to define a suitable temperature program and to optimize the calibration conditions. It was possible to determine Cu and Mn in the samples just after a simple dilution of samples with a 0.70 mol L−1 HNO3 solution, except in the case of grape juice. We compared the results obtained with the proposed method to those obtained after a traditional treatment based on acid digestion in a microwave oven, and no significant differences were observed (except for grape juice). The accuracy of the method was assessed through a recovery test, which provided recovery percentages in the range of 81–117%. Precision was always better than 8%, and the limits of quantification for Cu and Mn were 6 μg L−1 and 9 μg L−1, respectively. We analyzed twenty-two samples, and the concentrations of Cu and Mn were in the range of 24.1–321 μg L−1 and 116–3296 μg L−1, respectively. Statistical analysis using a two-way analysis of variance (ANOVA) at 95% confidence level showed that flavor and brand impacted on the concentration of the analytes in the samples. Among the samples analyzed, the grape juice presented the highest concentrations of both Cu and Mn.


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