Determination of B in body fluids by isotope dilution inductively coupled mass spectrometry with direct injection nebulization

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• 作者：Bellato ; Ana Cl&aacute ; udia S. ; Giné ; Maria Fernanda ; Meneg&aacute ; rio ; Amauri A.
• 关键词：Isotope dilution ; Inductively coupled plasma mass spectrometry ; Biological fluids ; Boron isotope ratios
• 刊名：Microchemical Journal
• 出版年：2004
• 出版时间：August, 2004
• 年：2004
• 卷：77
• 期：2
• 页码：119-122
• 全文大小：107 K

文摘

The determination of B in small volumes of undigested blood plasma and urine by isotope dilution and high efficiency direct injection nebulization (DIN) inductively coupled plasma mass spectrometry (ICP-MS) is proposed. The C interference over ¹¹B was removed by precipitating the samples proteins. Samples aliquots of 1 ml were spiked with an enriched ¹⁰B solution and shaken during 1 h to attain the isotopic equilibrium. Thereafter, the sample proteins were denaturated with nitric acid and the supernatant was analyzed. This procedure was effective to reduce C concentrations in approximately 94 % . Sample volumes of 50 μl were introduced into the ICP by the direct injection nebulizer producing transient signals lasting 30 s for B isotopes measurements. Precision of ¹⁰B/¹¹B measurements was characterized by relative standard deviation (RSD) lower than 1 % . The instrumental mass discrimination factor was lower than 5 % . Total B concentrations from 100 to 135 μg L⁻¹ in plasma and 0.499 to 3.021 mg L⁻¹ in urine samples were found. Reproducibility of triplicate samples was characterized by RSD<2.0 % for plasma and lower than 1.3 % for urine samples. Limit of detection (3σ) of 0.6 ng ml⁻¹ was calculated from synthetic blood plasma blank. Results of the denatured supernatant and digested plasma and urine samples were comparable at the 95 % confidence level.