气相色谱-质谱法测定人血清中葡萄糖含量

利用同位素稀释质谱法配制葡萄糖标准溶液、标记葡萄糖标准溶液以及校准比值混合溶液,向血清样品中加入D-[13C6]葡萄糖标记物作为内标。离心沉淀蛋白后,两步衍生化,通过气相色谱质谱联用仪测定高标校准混合液、血清样品以及低标校准混合液中葡萄糖与标记葡萄糖的峰面积比,利用括弧法计算血清样品中葡萄糖的准确含量。低标、高标血糖浓度分别为1150mg/kg、1396 mg/kg,相对标准偏差1.65%、2.24%,大幅降低了测量结果的不确定度。本方法与测定血糖浓度的其他方法比较,具有特异性高、灵敏度好,不易受血清中还原性物质的干扰等特点。

Determination of serum glucose by gas chromatography-mass spectrometry

An accurate and precise method to determine glucose concentration in serum is presented.We use iso-tope dilution to prepare a glucose standard solution,a D-[~(13)C_6]standard solution and a mixed solution,with addi-tion of D-[~(13)C_6]standard solution into serum as an internal standard.The protein was then precipitated by addition of anhydrous ethanol followed by centrifugation,and the supernatant was evaporated to dryness under nitrogen at 50 ℃.The glucose and D-[~(13)C_6]glucose in the sample were converted to derivatives after adding hydroxylamine hydrochloride solution in pyridine and acetic anhydride.Through measuring the peak areas of the high standard mixed solution,the serum sample and the low standard mixed solution by gas chromatography-mass spectrometry,we use the method of bracketing to calculate the content of serum glucose.The low standard and high standard set-um glucose concentrations were 1150 mg/kg and 1396 ms/kg with relative standard deviations of 1.65% and 2.24%,respectively,which can substantially reduce the uncertainty of the results obtained.