Flow injection spectrophotometric determination of Al in hemodialysis solutions

Abstract

A flow analysis (FA) system with spectrophotometric detection for Al determination in hemodialysis solutions was developed. The method was based on the reaction of Al with eriochrome cyanine R (ECR). The complex formed associated with cetyltrimethylammonium bromide (CTAB) — a cationic surfactant, which showed enough sensitivity to execute the direct analyte determination. All interferences were eliminated with the matrix matching calibration. The system presented the following analytic parameters: sensitivity ( m) of 8.10 × 10 −4 L μg −1, limit of detection (LOD) of 3.24 μg L −1 (3 σ), linear correlation coefficient of 0.9966 and linear range response from 10.8 to 650 μg L −1. The accuracy of the proposed method was checked by comparison with electrothermal atomic absorption spectrometry (ET-AAS) method. There were no differences among the results obtained from both methods, at a confidence level of 95% (paired t-test). Recovery tests were also made, values obtained were from 90.4 to 109 of recovery for Al-spiked samples.