scholarly journals Arsenic determination in naphtha by electrothermal atomic absorption spectrometry after preconcentration using multiple injections

2003 ◽  
Vol 18 (10) ◽  
pp. 1267 ◽  
Author(s):  
Marcio V. Reboucas ◽  
Sergio L. C. Ferreira ◽  
Benicio de Barros Neto
Keyword(s):  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Electrothermal Atomic Absorption Spectrometry ◽  
Absorption Spectrometry ◽  
Multiple Injections ◽  
Arsenic Determination

scholarly journals Trace Arsenic Determination in a TiO2 Pigment Matrix Using Electrothermal Atomic Absorption Spectrometry

2019 ◽  
Vol 25 (2) ◽  
pp. 123-131
Author(s):  
Matjaž Finšgar ◽  
Tamara Govejšek ◽  
Ksenija Gradišek
Keyword(s):  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Microwave Digestion ◽  
Pyrolytic Graphite ◽  
Electrothermal Atomic Absorption Spectrometry ◽  
Absorption Spectrometry ◽  
Calibration Procedure ◽  
Chemical Modifier ◽  
Relative Standard ◽  
Arsenic Determination

This work describes the use of electrothermal atomic absorption spectrometry in combination with a pyrolytic graphite-coated tube with a platform for trace arsenic (As) determination in titanium dioxide (TiO2) pigment. This type of matrix is challenging, as complete digestion in hydrofluoric acid-containing solution is needed. First, closed-vessel microwave digestion was performed for the full-sample decomposition. Next, a temperature program was optimized for drying, pyrolysis, and atomization temperatures. Furthermore, the use of a chemical modifier mixture was proposed that reduced the background contribution and prevented significant analyte loss and therefore improved the analytical procedure. The optimized method was validated for the detection (LOD) and quantification (LOQ) limits, the linear concentration range, accuracy, and precision. Special attention was devoted to the matrix-matching solutions in the calibration procedure. Linearity was confirmed in the 5.0 to 100.0 µg/L concentration range ( R2 = 0.999). The average recovery for 16 different real TiO2 pigment samples was 92.0%, and the relative standard deviation value for six replicate measurements was ≤10.4%. Moreover, the LOD and LOQ in terms of the TiO2 pigment mass was determined to be 0.2 µg/(g TiO2) and 0.7 µg/(g TiO2), respectively. The latter complies with Commission Directive 2008/128/EC, which does not allow more than 3 µg As/(g product) as the specific criteria of purity. Finally, based on scanning electron microscopy analysis of unused and several times used pyrolytic graphite-coated tubes, usage of the tube 250 times before replacement is recommended.

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