| Autor: |
Valfredo Azevedo Lemos, Sergio Luis Costa Ferreira, Adilson J. Curtius, Ricardo Erthal Santelli, Edgard Moreira Ganzarolli |
| Rok vydání: |
2001 |
| Předmět: |
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| Zdroj: |
Microchemical Journal. 68:41-46 |
| ISSN: |
0026-265X |
| DOI: |
10.1016/s0026-265x(00)00166-1 |
| Popis: |
The use of Amberlite XAD-2 modified by 2-(2-benzothiazolylazo)-2- p -cresol (BTAC) as a sorbent in an on-line pre-concentration system for lead determination has been proposed. The procedure is based on the sorption of lead(II) ions onto a minicolumn packed with modified Amberlite XAD-2, followed by elution with 0.10 mol l −1 hydrochloric acid and determination by flame atomic absorption spectrometry. The on-line flow system uses four three-way solenoid valves and is electronically controlled in a time-based mode. Chemical and flow variables were optimized. The results demonstrated that sample solutions containing lead(II) in the concentration range from 3.7 to 300.0 μg l −1 in a solution of pH between 6.5 and 8.5 could be determined, using a pre-concentration time of 2 min. The enrichment factor was 27 for a sample volume of 4.50 ml. The limit of detection was 3.7 μg l −1 . The relative standard deviations (R.S.D.) were in the range of 4.4–2.3% for lead concentrations from 50.0 to 300.0 μg l −1 , respectively. The method was tolerant to other ions usually present in biological samples. Good accuracy was assured by the analysis of biological reference materials. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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