肠外营养患者血清必需脂肪酸的气相色谱/质谱方法测定

Determination of the essential fatty acids in the serum of patients receiving parenteral nutrition with gas chromatography/mass spectrometry

目的:建立肠外营养患者血清中必需脂肪酸(C_8∶0、C_(10)∶0、C_(18)∶2、C_(18)∶3、C_(20)∶4)的气相色谱/质谱测定方法。方法:肠外营养患者的血清经正己烷提取和三氟化硼乙醚衍生,用BD-17MS(30 m×0.25 mm×0.25μm)柱分离,以十七烷酸为内标,对脂肪酸进行定量测定。结果:BD-17MS(30 m×0.25 mm×0.25 μm)毛细管柱能使6种待测脂肪酸得到很好的分离。方法在0.006 25～0.10 mg/ml范围内线性关系良好,相关系数(r)>0.999;最低检测限为10ng/ml。脂肪乳输注2h后,各脂肪酸浓度均升高,6 h时C_8∶0、C_(10)∶0有所下降,24 h下降到输注前或以下;C_(18)∶2、C_(18)∶3、C_(20)∶4 4～6h达高峰,24h下降到输注前或以下。结论:气相色谱/质谱方法用于测定血清必需脂肪酸,方法简便可靠、灵敏度高、分离度好,衍生化反应速度适中。

Objective：To develop a method for determination of the essential fatty acid profile （C8 ： 0,C10 ： 0, C18 ： 0,C18 ： 3,C20 ： 4） in plasma of patients receiving parenteral nutrition with gas chromatography/mass spectrometry. Methods：After extraction with n-hexane and deveriation using borontrifluoride diethyl ether, serum was separated on a BD-17MS （30 m × 0.25 mm× 0. 25 μm） column. The fatty acid was detected with heptadecoic acid [-CH3 （CH2）15 COOH] selected as the internal standard. Results： Six kinds of fatty acid was separated distinctly by BD-17MS column. The linear range of the method was 0. 006 25-0.10 mg/ml（r〉0. 999）. The detection limit was 10 ng/ml. The concentration of each kind of the fatty acid increased at 2 hours after fat emulsion injection. C8 ： 0 and C10 ： 0 levels were lowered at 6 hours, while C18 ： 2,C18 ： 3,C20 ： 4 levels reached the peak values at 4- 6 hours. At 24 hours of administration of fat emulsion, they were both lower than that before fat emulsion injection. Conclusion：The results show that this method is sensitive, accurate with satisfactory separation. The reaction of derivation is rapid.