TITLE:
Simple Spectrophotometric Sequential Injection Analysis System for Determination of Serum Calcium
AUTHORS:
Yuwadee Boonyasit, Chakorn Chinvongamorn, Orawon Chailapakul, Wanida Laiwattanapaisal
KEYWORDS:
Sequential Injection Analysis System; Calcium; Arsenazo III; Green Chemistry;Spectrophotometry; Clinical Analysis
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.3 No.2,
February
22,
2012
ABSTRACT: A sequential injection analysis (SIA) system for the determination of total calcium in blood has been implemented. The assay principle is based on the arsenazo III method, in which the indicator’s complex with calcium forms a blue-purple colour. The absorbance peak height at 650 nm was proportional to the calcium content in samples. A linear range was obtained from 2.5 - 15 mg?dL–1 (r2 = 0.999), with a detection limit of 0.430 mg?dL–1 (3σ). Magnesium, glucose, hae-moglobin, and bilirubin at 123, 1,000, 50, and 0.5 mg?dL–1, respectively, were not found to interfere with the proposed system significantly (recovery 99.1% - 104.4%). The sampling frequency was 30 h–1, in which the carry-over effect was negligible (0.69%). The proposed SIA system was successfully applied to the determination of calcium from serum samples (r2 = 0.970; n = 30).