尿素酶预处理-气相色谱-质谱法诊断琥珀酸半醛脱氢酶缺陷病

Urease Pretreatment-Gas Chromatography-Mass Spectrometry in the diagnosisof succinic semialdehyde dehydrogenase deficiency

本文探讨琥珀酸半醛脱氢酶 (succinicsemialdehydedehydrogenase ,SSADH)缺陷病各尿液标志物的气相色谱 质谱法 (GasChromatography MassSpectrometry,GC MS)分析特征。收集SSADH患儿的尿液标本 ,经去尿素、加内标 (正十七酸 )、除蛋白、真空干燥处理 ,残余物进行三甲基硅烷化衍生后进样行GC MS法分析。尿液中可检测到明显的 4 羟基丁酸、2 ,4 二羟基丁酸、3,4 二羟基丁酸和 4 ,5 二羟基己酸信号。在TIC图上 ,其绝对保留时间 (相对保留时间 )分别是 6 32min(0 4 34) ,7 80min(0 5 36 ) ,7 94min(0 5 4 6 ) ,8 80min ,8 90min(0 6 0 5 ,0 6 12 )。在质谱图上 ,其特征离子 (m z,TMS)分别是M 15 (2 33,2 ) ,M 15 (32 1,3) ,M 15 (32 1,3) ,M 15 (349,3)。GC MS法分离鉴定尿液代谢成分 ,可作为诊断该病的一种可靠手段。

To explore the analytic characteristics of the urinary markers of succinic semialdehyde dehydrogenase (SSADH) deficiency, by gas chromatography-mass spectrometry(GC-MS),urine sample of a child with SSADH deficiency was collected, urea was decomposed with urease, n-heptadecanoic acid was added as an internal standard,protein was denaturated with ethanol and precipitate was removed by centrifugation, evaporation was performed to dryness, the residue was trimethylsilylly derivatized with BSTFA/TMCS, and then analyzed with GC-MS.Large quantity of 4-hydroxybutyric acid, 2,4-dihydroxybutyric, 3,4-dihydroxybutyric acid and 4,5-dihydroxyhexanoic acid, were detected in the urine sample. In TIC profile, their retention time(relative retention time) were 6.32min(0.434), 7.80min(0.536), 7.94min (0.546), and 8.80min,8.90min(0.605,0.612), respectively, with charateristic ions, in mass spectrums, M-15(233,2), M-15(321,3), M-15(321,3),and M-15(349,3), respectively. Analysis of urinary metabolites by GC-MS is a reliable tool for the diagnosis of SSADH deficiency.