Detection of arsenic and lead ions in water through validation of the electrothermal atomic absorption method

Abstract

The validation of the electrothermal spectrometry method for Arsenic and lead determination in water samples guarantees the quality of analytical data. The study was carried out at AQLAB. A theoretical and technical investigation was applied to ensure the reliability and accuracy of the analytical method. Parameters such as INEN standards, Eurachem international standards, AQLAB internal documents and environmental standards were used to validate the process. Several readings were performed on different samples to make calibration curves for As and Pb, evaluate the method's linearity, and obtain information on the slope, intercept and determination coefficient. Statistical calculations were used to determine the limit of detection and quantification, repeatability, reproducibility, trueness and uncertainty. The results show that the hypotheses were fulfilled, calibration curves with determination coefficient higher than 0.995, repeatability standard deviation lower than 16%, calculated F < critical F (4.96), calculated t student < theoretical (2.23), trueness was between 100.29-110.18 and 99.64-107.92%, uncertainty was 20% range 0.005 to 0.10 mg/L and 15% range 0.01-0.20mg/L, limit of detection was 0.001 and 0.005 mg/L and limit of quantification was 0.01 and 0.02mg/L, respectively. Therefore, the validation method was robust and accurate. Keywords: water samples, analytical data, reliable results, Arsenic, Lead, validation.