本研究係探討以氘同位素安非他命爲内部標準品於氣相層析質譜儀分析尿液中安非他 命含量之適用性。本計晝所用之安非他命氣同位素藥物爲amphetamine-d5其與原待測藥物 amphetamine-d〇經衍生化試劍trichloroacetic anhydride衍生化後探討全掃描質譜圖及指定離子 碎片監測（SIM)圖譜之離子碎片強度是否相互干擾，並以迴歸方式分析其實際應用在定量上 之可行性。研究結果顯示，由兩者之全掃描質譜圖來分析，兩者之離子碎片除m/z 91, 192 外，其他主要離子之相互干擾甚低，其中amphetainine-dQ之trichloroacetic衍生物（TCA-amphetamine'd0)適用之離子爲 118，188，190 及 91 ;而 amphetairdne-d5 之 trichloroacetic 衍生 物（TCA-amphetamine-d5)適用之離子則爲123及196。由選定離子監測質譜圖（SIM)來分析， 兩者之選定離子碎片相互干擾甚低，其中TCA-amphetamine-d適用之離子爲190, 188, 118及 91，TCA-amplietamine-d5適用之離子爲196, 194及123。由其適用之離子中，本研究選用 TCA-amphetamine-d。之離子碎片190及TCA-amphetarrdne-d5之離子碎片194爲定量用離子， 以選定離子監測質譜中190與194之相對離子強度比値對標準品amphetamine-do之序列濃度 31.25, 62.5, 125, 250, 500, 1000, 2000 ng/mL進行迴歸分析，於上述i度範圍内，具有良好的 線性關係（n = 7, SD = 0.03569，相關係數爲 0.9987)。因此以 trichloroacetic anhydride 爲衍生 化試劑時，amphetamine-d5應可供作氣相層析質譜法分析尿液中安非他命含量時的内部標準 品。

This study examined the accessibility of using amphetamine-d5 (side chain) as an internal standard in quantitative analysis of the trichloroacetyl derivative of urinary amphetamine by gas chromatography I mass spectrometry (GC/MS). In GC/MS analysis , fragments with minimal interference between the assay protocol and the internal standard were selected for quantitation. In the full-scan mode, no interference from TCA-amphetamine-d5, the trichloroacetyl derivative of amphetamine-d5, was observed for the fragments of trichloroacetylamphetamine (TCA-amphetamine) with m/z 190, 188, 118 and 91. On the other hand, no interference from TeAamphetamine was indicated in fragments of m/z 196 and 123 of TCA-amphetamine-d5 . In the selective ion monitoring mode (SIM), the interference between m/z 190, 188, 118 and 91 of TCA-amphetamine and m/z 196, 194 and 123 of TCA-amphetamine-d5 was minimaL The fragments of m/z 190 from TCA-amphetamine and m/z 194 from TCA-amphetamine-d5 were thus selected for quantitation of urinary amphetamine by SIM. Calibration graph derived from the ratio of relative intensity of m/z 190 to m/z 194 versus the concentration of urinary amphetamine was linear over the concentration range of 31.25 - 2000 ng/mL (n=7, SD=0.0357, r=0.9987). Amphetamine-d5 was demonstrated to be a suitable internal standard in quantitative analysis of the trichloroacety1 derived urinary amphetamine by SIM analysis with GC/MS.