Lehmann W D, Bahr U, Schulten H R
Biomed Mass Spectrom. 1978 Sep;5(9):536-9. doi: 10.1002/bms.1200050906.
The use of field desorption mass spectrometry for the determination of lithium in body fluids at therapeutic levels--ppm region--as well as at the normal level--ppb region--has been developed. The use of a stable isotope enriched internal standard, together with the outstanding sensitivity of field desorption for alkali cations and the high specificity of mass spectrometry, allows a quantitative determination of lithium in microlitre amounts of body fluids, such as plasma, saliva and urine. The assay allows a determination of lithium even at ultratrace concentrations where routine spectroscopic procedures cannot be applied. Analysis of plasma required a simple protein precipitation, whereas saliva and urine could be analysed without treatment. The precision of the data obtained ranged from 2--10%. The time consumption for one analysis in routine work is about 20--30 min.
已开发出利用场解吸质谱法测定治疗水平（ppm范围）以及正常水平（ppb范围）体液中的锂。使用稳定同位素富集内标，结合场解吸对碱金属阳离子的出色灵敏度和质谱的高特异性，能够对微升量的体液（如血浆、唾液和尿液）中的锂进行定量测定。该测定方法即使在无法应用常规光谱程序的超痕量浓度下也能测定锂。血浆分析只需简单的蛋白质沉淀，而唾液和尿液无需处理即可分析。所获得数据的精密度在2%至10%之间。常规工作中一次分析的耗时约为20至30分钟。
