Quantification of human urine aldosterone by LC-MS/MS / 中华检验医学杂志

ABSTRACT

Objective To establish a method for quantification of aldosterone (ALD) in urine by LC-MS/MS.Methods This study was the establishment and validation of methodology for urine ALD using LC-MS/MS.The urine samples were hydrolyzed at 37 ℃ by hydrochloric acid and the deuterated isotope internal was then added , followed by protein precipitation and anion exchange solid phase extraction (SPE). After SPE, the eluates were detected in the negative electro-spray ionization mode and multiple reaction monitor mode.The linearity, lower limits of quantification , precision and recovery of LC-MS/MS were evaluated.Urine and serum ALD of 80 subjects were measured by LC-MS/MS to evaluate the correlation of ALD detected in serum and 24 h urine.70 urine samples were collected and measured with LC-MS/MS and CLIA method for ALD comparison.14 participants were recruited to study the distribution of urine ALD in apparent healthy population .Results The analytical time was 4.5 min.Linearity of ALD was good in the range of 2-1 000 pg/ml (R2＞0.990); the repeatability and CV of ALD were less than 4.0% and 5.0%respectively; the recovery of urine ALD ranged between 100.4%and 108.2%; the lower limits of detection was 1 pg/ml.The correlation between urine and serum ALD was 0.396.The method comparison resulted in linear equation Y＝0.998 8X+0.046 4(r＝0.991).The distribution of urine ALD in apparent healthy subjects were 0.74-17.09 μg/24 h.Conclusion A reliable and specific LC-MS/MS method for urine ALD was established.And condition of the acid hydrolyzation for urine ALD was optimized .The method is simple, rapid and it can be used for the diagnosis of primary aldosteronism.