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Determination of Total Calcium in Plasma by Flow Injection Analysis with Tris(2,2′‐bipyridyl)ruthenium(II) Electrochemiluminescent Detection
Author(s) -
Shi Lihong,
Liu Xiaoqing,
Li Haijuan,
Xu Guobao
Publication year - 2006
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200603555
Subject(s) - ruthenium , reagent , chemistry , calcium , flow injection analysis , chromatography , selectivity , detection limit , oxalate , analytical chemistry (journal) , atomic absorption spectroscopy , linear range , inorganic chemistry , organic chemistry , catalysis , physics , quantum mechanics
Abstract We described here a new method for the determination of total calcium in plasma. The method is based on the precipitation of calcium with excess oxalate and the measurement of residual oxalate by flow injection analysis with Ru(bpy) 3 2+ electrochemiluminescent detection. It has the advantages of extremely stable reagent, user‐friendly instrument, high selectivity, good analytical recovery, wide dynamic range, and nice correlation with atomic absorption spectroscopy. The calibration plot for calcium is linear over a concentration range from 0.5 mmol L −1 to 4.8 mmol L −1 , which is wider than those obtained by most other methods. The analytical recoveries for plasma calcium are 98.4–101.2% with coefficients of variation (CVs) of 1.96–2.52%. The within‐day CVs range from 0.76% to 0.95%, and between‐day CVs were from 1.12% to 1.46%. The time for each injection is one minute. Because the proposed method can be readily carried out on increasingly popular instruments for Ru(bpy) 3 2+ ECL immunoassays and DNA probe assays, Ru(bpy) 3 2+ ECL method is suitable for routine clinical analysis of calcium.