Continuous in vivo Monitoring of Blood Diffusible Calcium Using On-line Microdialysis Sampling Coupled with Flame Atomic Absorption Spectrometry

• Published in: Analytical Sciences Vol. 21; no. 3; pp. 225 - 229
• Main Authors: TSENG, Wei-Chang, SUN, Yuh-Chang, LEE, Cheng-Fa, YANG, Mo-Hsiung, HUANG, Yeou-Lih
• Format: Journal Article
• Language: English
• Published: Japan The Japan Society for Analytical Chemistry 01.03.2005; Japan Science and Technology Agency
• Subjects: Animals; Calcium - blood; Calcium - metabolism; Diffusion; Male; Microdialysis - methods; Rabbits; Reproducibility of Results; Sensitivity and Specificity; Spectrophotometry, Atomic - methods
• ISSN: 0910-6340; 1348-2246
• DOI: 10.2116/analsci.21.225

A direct, rapid and continuous in vivo monitoring of diffusible calcium in the blood of living rabbits has been developed using microdialysis sampling coupled on-line with flame atomic absorption spectrometry. Microdialysates perfused through implanted microdialysis probes were collected with a sample loop on an injection valve and directly introduced into the flame atomizer by a carrier solution. An ultrapure saline solution (0.9% NaCl, pH 7.2) was used as the perfusion solution at a flow rate of 20 µl min-1 via the microdialysis probe. A 0.1% La solution in 0.5% HNO3 solution was employed as the carrier solution at a nebulizer uptake flow rate of 2.5 ml min-1. The interval for each determination was 2.5 min (2 min of sampling time, 20 s of read time and 10 s of washing time). The performance characteristics of the on-line microdialysis-FAAS system were validated as follows: linearity range, 0 - 100 mg l-1; detection limit (3 σ, n = 7), 3.66 mg l-1; precision (RSD, n = 50), 6.2%. For the evaluation of analytical accuracy, the proposed on-line method was compared with the in vivo no net flux method. The use of an on-line microdialysis-FAAS system permitted the in situ, dynamic and continuous in vivo monitoring of diffusible calcium in the blood of the living rabbits after CaCl2 administration with a temporal resolution of 2.5 min.