对应用分散液液微萃取（DLLME）于气相色谱-质谱法（GC-MS）测定尿液中毒品的方法作了改进。分析时，在尿样2.0 mL中加入20.0 mg·L^-1 SKF525A内标溶液100 μL，并调节其酸度至pH 12后，增加了加入N-丙基乙二胺（PSA）50 mg并振荡、离心的步骤，达到除去尿液中脂肪酸等杂质的目的，在后续操作中不会出现脂状沉淀。之后，取其上清液，加入分散剂异丙醇400 μL和萃取剂四氯化碳20 μL，轻轻振荡1 min并离心5 min后即可用微量移液器提取离心管尖底的小液滴1 μL，按GC-MS工作条件测定尿样中甲基苯丙胺、3，4-亚甲基二氧基苯丙胺（MDMA）和氯胺酮等3种毒品，其标准曲线的线性范围均在0.1~10.0 mg·L^-1之间，检出限（3S/N）也相同，均为0.01 mg·L^-1。试验测得3者的平均回收率依次为76.4%，83.2%，103%；三者测定值的相对标准偏差（n=5）依次为6.7%，5.3%，6.7%（日内）和7.5%，5.9%，6.6%（日间）。

A modification for the dispersion liquid-liquid micro extraction (DLLME) in the sample pretreatment of rapid determination of 3 illicit drugs (i.e., methamphetamine, MDMA and ketamine) in human urine by GC-MS in hyphenation was proposed. In the analytical procedure, after the urine sample (2.0 mL) was mixed with 100 μL of 20.0 mg·L^-1 internal standard solution of SKF525A, and its acidity was adjusted to pH 12, a modification of addition of 50 mg of PSA to the solution was made at this stage to remove impurities of fatty acid in urine, thus no precipitation of footy substance would happen in succeeding manipulations. After the addition of PSA, the mixture was centrifuged and the surpernatant was taken, to which 400 μL of iso-propyl alcohol (as dispersant) and 200 μL of CCl₄ (as extractant) were added. The mixture was shocked lightly for 1 min and centrifuged for 5 min. 1 μL of the extractant (CCl₄) at the shape bottom of the centrifuging tube was taken with a micropipet, and used for GC-MS determination of the 3 illicit drugs. Standard curves of the 3 drugs were found to have the same linearity range between 0.1 to 10.0 mg·L^-1 and same detection limit (3S/N) of 0.01 mg·L^-1. Test for recovery was made by standard addition method at 3 concentration levels, giving average recoveries of 76.4%, 83.2%, 103% for the 3 drugs respectively. Values of RSDs (n=5) found from the determined values of the 3 drugs were 6.7%, 5.3%, 6.7% (intraday) and 7.5%, 5.9%, 6.6% (interday) respectively.