代謝是維持人體各項生理機能得以順利運作的基礎，透過比對正常人與患者代謝物種類、濃度的差異，可以作為醫師搭配臨床症狀進行診斷之參考，這也是近年代謝體學蓬勃發展的原因。在遺傳代謝疾病的領域，無法被代謝或異常代謝的產物會在患者體內大量堆積，然而患者在早期通常不會出現明顯臨床症狀，且症狀則與多種疾病雷同，容易造成誤診。如吞嚥困難、肌肉張力異常也是小兒腦性麻痺常見的臨床症狀，嗜睡、嘔吐、抽筋、餵食困難則常見於新生兒敗血症、雷氏症候群。是故尿液有機酸之定性與定量尤為重要，透過了解遺傳代謝疾病患者與正常人檢體中四十四種有機酸濃度的差異，可盡早確診疾病項目、開始治療。然而尿液中具有大量且複雜的基質，建立一套有效避免基質干擾、保留待測物，並能夠穩定分析的方法，才能成為輔助診斷的利器。一般研究使用液相萃取搭配液相或氣相層析質譜儀，然而經過比對後發現各篇研究所得的正常範圍歧異相當大，是由於液相萃取容易因操作人員之差異與該實驗方法專一性不足。是故，本研究借重自動固相萃取裝置之穩定性與方法之專一性，經最佳化之沖提條件及反應條件，可以提供建立尿液中四十四種有機酸快速與準確的分析方法，並建立正常範圍作為輔助診斷之依據。

Organic acidemia (OA) is a group of inborn error of metabolism that are caused by defects in that degradation of branched chain amino acids. Early symptoms are not specific for clinical diagnosis which leads misdiagnosis . Certain symptoms observed on organic acidemia are also found on other diseases, such as dysphagia and dystonia both symptoms of poliomyelitis. Or lethargy, vomiting and cramp which are common symptoms seen to neonatal septicemia and Reye's syndrome. Conventional method that is liquid-liquid extraction coupled to GC-MS generally applied semi-quantitation. This leads to great variation between analysis and thus results in great differential of results. To solve the issue, a sensitive and specific method for the qualitative and quantitative of relevant organic acids accumulated in newborn urine is important. Our aim is to set up a fast, high through-put and precise analytical method based on synthetic reference substance using auto-solid phase extraction couple to gas chromatography-mass spectrometry to provide accurate quantitation and qualification for clinical diagnosis of organic acidemia.

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