胃蛋白酶原光激化学发光免疫测定方法的建立

目的建立一种检测人血清胃蛋白酶原浓度的光激化学发光免疫测定方法。方法采用双抗体夹心法建立检测人血清中胃蛋白酶原Ⅰ和胃蛋白酶原Ⅱ浓度的方法,评估其分析灵敏度、回收率和批内精密度,并与雅培(化学发光法)进行比较。结果胃蛋白酶原Ⅰ/Ⅱ的分析灵敏度分别为0.8ng/mL和0.6ng/mL,回收率分别为100.3%、106.5%,批内变异系数(CV)为0.93%~4.1%、1.2%~4.3%,与化学发光法的相关性较好(r=0.99)。结论该方法测定胃蛋白酶原具有较高灵敏度、精密度和准确性,适用于临床。方法建立后可进一步进行长期稳定性试验。     

骨转换标志物在红斑狼疮骨质疏松治疗的应用

目的 探讨骨转换标志物在红斑狼疮患者骨质疏松监测中的应用.方法 将确诊为骨质疏松的红斑狼疮病人分为高转换型组及低转化型组,组内再分为治疗组与对照组.监测其治疗前、治疗3、6、12个月后复查骨转换标志物变化.结果 骨质疏松的狼疮患者,β-CTx治疗前、后分别为（0.784 ±0.168） ng/ml和（0.454±0.136） ng/ml,P1NP治疗前、后分别为（85.5±15.1） ng/ml和（45.3±12.9）ng/ml,抗骨质疏松治疗后骨转换标志物明显下降（P＜0.05）.结论 骨转换标志物在抗骨质疏松治疗后均有下降,其变化趋势与患者骨骼疼痛缓解趋势一致,其可作为监测骨质疏松疗效的有效指标.     

UPLC法同时测定缬沙坦氢氯噻嗪片中缬沙坦和氢氯噻嗪的含量

目的:建立同时测定缬沙坦氢氯噻嗪片中缬沙坦和氢氯噻嗪含量的方法。方法:采用超高效液相色谱法。色谱柱为Phenomenex C_(18),流动相为[0.1%磷酸溶液-乙腈(95∶5,V/V)]-[0.1%磷酸溶液-乙腈(5∶95,V/V)](梯度洗脱),流速为0.25 mL/min,检测波长为272 nm,柱温为35℃,进样量为1.5μL。结果:缬沙坦和氢氯噻嗪检测质量浓度线性范围分别为8.1~324.2μg/mL(r=0.999 9)、1.2~50.1μg/mL(r=0.999 9);定量限分别为0.24、0.04 ng,检测限分别为0.06、0.01 ng;精密度、稳定性、重复性试验的RSD<2.0%;加样回收率分别为97.69%~100.35%(RSD=1.03%,n=9)、98.27%~100.60%(RSD=0.83%,n=9)。结论:该方法操作简单、快速,结果准确,可用于缬沙坦氢氯噻嗪片中缬沙坦和氢氯噻嗪含量的同时测定。     

UPLC-MS/MS法同时测定苦黄注射液中7种成分的含量

目的:建立同时测定苦黄注射液中苦参碱、槐果碱、大黄素、大黄酸、绿原酸、柴胡皂苷a、芦荟大黄素含量的方法。方法:采用超高效液相色谱-串联质谱法。色谱柱为Phenomenex Kinetex C_(18),流动相为甲醇-0.1%甲酸(梯度洗脱),流速为0.5 mL/min,柱温为20℃,进样器温度为10℃,平衡时间为4 min,进样量为5μL。离子化模式为电喷雾电离,源喷射电压分别为5 500、-4 500 V,雾化气压力为4.14×10~5Pa,加热气压力为4.48×10~5Pa,帘气压力为1.72×10~5Pa,离子源温度为600℃,工作模式为多反应监测模式。结果:苦参碱、槐果碱、大黄素、大黄酸、绿原酸、柴胡皂苷a、芦荟大黄素检测质量浓度线性范围分别为1.25~80.0 ng/mL(r=0.999 3)、1.10~70.0 ng/mL(r=0.999 5)、0.16~10.5 ng/mL(r=0.999 3)、2.61~168 ng/mL(r=0.999 3)、1.50~96.0 ng/mL(r=0.999 3)、1.48~94.5 ng/mL(r=0.999 6)、6.11~391 ng/mL(r=0.999 1);定量限分别为0.061、0.109、0.041、1.313、0.500、0.492、3.055 ng/mL,检测限分别为0.025、0.054、0.016、0.656、0.150、0.148、1.528 ng/mL;精密度、稳定性、重复性试验的RSD≤3%;加样回收率分别为95.45%~99.45%(RSD=1.43%,n=6)、97.50%~101.00%(RSD=1.50%,n=6)、95.67%~101.73%(RSD=2.85%,n=6)、97.17%~100.57%(RSD=1.16%,n=6)、95.19%~98.90%(RSD=1.71%,n=6)、95.38%~103.85%(RSD=3.39%,n=6)、95.50%~101.17%(RSD=1.20%,n=6)。结论:该方法简便、高效、准确、可靠,适用于同时测定苦黄注射液中7种有效成分的含量。     

ICP-MS法同时测定广西白背叶药材中30种微量元素的含量

目的:建立同时测定广西白背叶药材中30种微量元素含量的方法。方法:采用电感耦合等离子体质谱法。射频功率为1 550 W,采样深度为10 mm,载气流速为1.05 L/min,雾化室温度为2℃,蠕动泵频率为0.10 rps,碰撞模式为氦,气流量为4.2 m L/min。结果:铝、钒、铬、锰、铁、镍、铜、锌、镓、砷、铷、钼、镉、锑、铯、钡、镧、铈、镨、钕、铕、钆、镝、钬、铒、镥、汞、铊、铅、铀检测质量浓度线性范围分别为10～1 000 ng/mL(r=0.999 9)、0.1～5 ng/mL(r=0.999 9)、0.1～5 ng/mL(r=0.999 9)、10～1 000 ng/mL(r=0.999 9)、10～1 000 ng/mL(r=0.999 9)、0.1～5 ng/mL(r=0.999 7)、0.5～100 ng/mL(r=0.999 7)、1～500 ng/mL(r=0.999 8)、1～100 ng/mL(r=0.999 7)、0.5～50 ng/mL(r=0.999 9)、0.5～50 ng/mL(r=0.999 9)、0.1～10 ng/mL(r=0.999 9)、0.1～10 ng/mL(r=0.999 9)、0.1～10 ng/mL(r=0.999 9)、0.1～10 ng/mL(r=0.999 9)、1～500 ng/mL(r=0.999 9)、0.1～10 ng/mL(r=0.999 9)、0.1～10 ng/mL(r=0.999 9)、0.1～10 ng/mL(r=0.999 9)、0.1～10 ng/mL(r=0.999 8)、0.1～10 ng/mL(r=0.999 9)、0.1～10 ng/mL(r=0.999 9)、0.1～10 ng/mL(r=0.999 9)、0.1～10 ng/mL(r=0.999 9)、0.1～10 ng/mL(r=0.999 9)、0.1～10 ng/mL(r=0.999 8)、0.1～5 ng/mL(r=0.998 4)、0.1～10 ng/mL(r=0.999 9)、0.5～100 ng/mL(r=0.999 7)、0.1～10 ng/mL(r=0.999 9),定量限≤0.44 mg/kg,检测限≤0.11 mg/kg;精密度、稳定性、重复性试验的RSD≤10.0%;加样回收率为80.45%～116.68%(RSD为0.47%～5.83%,n=6)。药材样品中Mn、Ba、Fe、Al的含量最高。结论:该方法操作简便,精密度、稳定性、重复性好,可用于广西白背叶药材中30种微量元素含量的同时测定;药材中有害元素的含量符合国家相关标准。     

HPLC-MS/MS法测定桑菊感冒丸中3种成分的含量

目的:建立同时测定桑菊感冒丸中芦丁、连翘苷和桔梗皂苷D含量的方法。方法:采用高效液相色谱-串联质谱法。色谱柱为Waters Atlantis C_(18),流动相为乙腈-0.1%甲酸溶液(梯度洗脱),流速为0.2 mL/min,柱温为35℃,进样量为10μL。离子源为电喷雾离子源,采用多反应监测扫描模式和正离子检测模式,干燥气和雾化气均为高纯氮气,干燥气温度为270℃,干燥气流量为25 L/min,鞘气流量为10 L/min,毛细管电压为4 500 V,喷嘴电压为2 000 V,扫描时间为0.1 s。结果:芦丁、连翘苷和桔梗皂苷D检测质量浓度线性范围分别为0.010 82~2.164μg/mL(r=0.999 7)、0.010 18~2.036μg/mL(r=0.999 4)、0.010 27~2.054μg/mL(r=0.999 7);定量限分别为1.250、0.260、2.720 ng/mL,检测限分别为0.380、0.078、0.820 ng/mL;精密度、稳定性、重复性试验的RSD<3.0%;加样回收率分别为97.88%~99.88%(RSD=0.72%,n=6)、98.48%~103.13%(RSD=1.91%,n=6)、98.79%~101.41%(RSD=1.05%,n=6)。结论:该方法操作简便,精密度、稳定性、重复性好,可用于桑菊感冒丸中芦丁、连翘苷和桔梗皂苷D含量的同时测定。     

双波长HPLC法同时测定益肾衍嗣丸中4种成分的含量

目的:建立同时测定益肾衍嗣丸中阿魏酸、梓醇、大黄素和大黄素甲醚含量的方法。方法:采用双波长高效液相色谱法。色谱柱为Kromasil-C_(18),流动相为甲醇-0.1%磷酸溶液(78∶22,V/V),流速为1.0 mL/min,检测波长为280 nm(阿魏酸、大黄素和大黄素甲醚)、210 nm(梓醇),柱温为30℃,进样量为10μL。结果:阿魏酸、梓醇、大黄素和大黄素甲醚检测质量浓度线性范围分别为0.090 8~2.270 0μg/mL(r=0.999 9)、0.199 0~4.975 0μg/mL(r=0.999 3)、0.354 0~8.850 0μg/mL(r=0.999 9)、0.3360~8.400 0μg/mL(r=0.999 7);定量限分别为14.66、8.75、10.26、13.68 ng,检测限分别为5.66、2.67、3.78、4.25 ng;精密度、稳定性、重复性试验的RSD<2.0%;加样回收率分别为101.15%~102.73%(RSD=0.58%,n=6)、99.20%~101.69%(RSD=1.20%,n=6)、100.90%~101.36%(RSD=0.16%,n=6)、95.64%~98.96%(RSD=1.49%,n=6)。结论:该方法准确可靠,操作简单,适用于益肾衍嗣丸中4种成分含量的同时测定。     

LC-MS-MS法测定血浆中多西他赛和紫杉醇浓度及在乳腺癌患者中的应用

目的：建立一种快速、灵敏的液相色谱－串联质谱（LC-MS/MS）法检测乳腺癌患者血浆中多西他赛、紫杉醇的浓度。方法：多西他赛和紫杉醇互为内标,血浆样品100μL加入1 mL叔丁基甲醚萃取,分离有机相,以氮气吹干后流动相复溶进样。色谱柱为Agilent Eclipse XDB-C18（2.1 mm×100 mm,3.5μm）,流动相为0.4%甲酸水溶液-0.4%甲酸乙腈溶液（20∶80,v/v）,流速0.3 mL·min-1,柱温为40℃。采用多反应监测（MRM）进行定量,电喷雾电离源（ESI）正离子方式进行检测,多西他赛与紫杉醇用于定量分析的检测离子对分别为m/z 808.5→m/z 527.2和m/z 854.3→m/z 569.4。结果：多西他赛和紫杉醇的线性范围分别为5.0~1000 ng·mL-1和1.0～500 ng· mL-1,最低检测浓度分别为5.0 ng·mL-1和1.0 ng·mL-1。两药低、中、高三个浓度的批内和批间RSD均<15%,平均提取回收率分别为65.9%~84.3%和90.4%~106.5%。结论：本法快速、准确、灵敏、专属性强,适用于同步测定多西他赛和紫杉醇血药浓度及其在中国乳腺癌患者中的药动学研究。     

血清PCT与心脏标志物对脓毒症儿童病情程度的检测效果

目的探究血清PCT和心脏标志物对脓毒症儿童患者病情程度的检测效果,以寻找最优方法,提高检测准确度。方法选取2014年10月~2016年5月在我院接受治疗的160例ICU儿童患者,按照病情程度分为轻脓毒症组、脓毒症组,其中轻脓毒症患者72例,脓毒症患者88例,对两组患者的血清PCT、肌酸激酶同工酶(CK-MB)、氨基末端脑钠肽前体(NT-proBNP)、超敏肌钙蛋白T(cTnT-hs)水平进行比较,并对分别进行血清PCT、肌酸激酶同工酶、cTnT-hs、NT-proBNP进行检测的敏感性、特异性结果与联合四种方式检测的结果进行比较。结果轻脓毒症患者血清PCT、肌酸激酶同工酶、NT-proBNP和cTnT-hs水平分别为(7.37±0.11)ng/mL、(15.28±3.22)IU/L、(2340.05±34.13)pg/mL、(0.02±0.01)ng/mL,脓毒症患者分别为(10.37±3.28)ng/mL、(30.84±4.38)IU/L、(3849.05±128.37)pg/mL、(0.05±0.01)ng/mL,轻脓毒症组和脓毒症组在四种检测方式比较差异均具有统计学意义(P<0.05);四种方法联合诊断和联合诊断结果显示,肌酸激酶同工酶、NT-proBNP、血清PCT和cTnT-hs特异性分别为87.5%、81.2%、83.0%、81.2%,敏感度分别为93.2%、89.8%、91.0%、87.5%、97.7%,与联合诊断相比较差异具有统计学意义(P<0.05)。结论血清PCT与心脏相关标志物都可以较好的检测脓毒症儿童的病情程度,但四者联合检测是最准确的方法。     

HPLC-MS/MS法测定比格犬血浆中甲磺酸胺银杏内酯B的含量

建立HPLC-MS/MS检测beagle犬血浆中甲磺酸胺银杏内酯B(XQ-1H)含量的方法。采用Xterra MS C18(2.1 mm×100 mm,5μm)柱,流动相为0.1%甲酸溶液-甲醇(75∶25),以拉呋替丁为内标,流速为0.2 mL/min,进样量5(L,柱温20℃;采用三重四级杆质谱仪,电喷雾离子化(ESI+)方式,以多反应离子监测方式(MRM)进行定量检测。该方法的线性范围为5.0~5044.0 ng/mL,最低定量限为5.0 ng/mL,方法回收率为94.2%,批内、批间精密度(RSD)分别为4.2%和4.5%。本方法灵敏度高、专属性强,操作简便,可用于甲磺酸胺银杏内酯B在比格犬体内药物血药浓度检测。     

气相色谱串联质谱法测定二甲双胍格列本脲胶囊(Ⅱ)中N-亚硝基二甲胺的含量

目的:建立了二甲双胍格列本脲胶囊(Ⅱ)中基因毒性杂质N-亚硝基二甲胺(NDMA)的测定方法.方法:采用气相色谱-三重四级杆质谱仪,以多反应监测模式(MRM)进行测定,按外标法定量.仪器条件:EI源温度:230?℃;电子能量:70?eV;碰撞气:高纯氮气,碰撞气流速:1.5?mL/min.载气:高纯氦气,载气流速为1.0...     

UFLC-MS/MS法测定人胎盘灌流液中氟西汀、去甲氟西汀、舍曲林的浓度及其胎盘透过率

目的 建立测定人胎盘灌流液中氟西汀、去甲氟西汀、舍曲林浓度的方法并测定胎盘透过率.方法 以格列本脲为内标,采用蛋白沉淀法对样品进行前处理,采用超快速液相色谱-串联质谱(UFLC-MS/MS)法检测.以SynergiTM Hydro-RP 80A LC为色谱柱,以水(含0.1％甲酸)-乙腈(含0.1％甲酸)为流动相进行梯...     

LC-MS/MS法测定厄贝沙坦中基因毒性杂质N-亚硝基二甲胺和N-亚硝基二乙胺

建立同时检测厄贝沙坦中N-亚硝基二甲胺(NDMA)和N-亚硝基二乙胺(NDEA)的液质联用(liquid chromatography-tandem mass spectrometry,LC-MS/MS)方法。选择大气压电离串联四极杆质谱(APCI+MRM)模式进行检测,流动相为0.1%甲酸水溶液-0.1%甲酸甲醇溶液梯度洗脱。结果表明该方法专属性良好,标准曲线线性范围分别为1~120 ng·mL^-1(NDMA)和0.4~48 ng·mL^-1(NDEA);检测限浓度分别为0.5 ng·mL^-1(NDMA)和0.2 ng·mL^-1(NDEA);精密度RSD均<3.0%;准确度为96.1%~106.2%,重复性良好;样品的提取回收率分别为102.5%(NDMA)和99.9%(NDEA);对照溶液在进样器和0℃下放置24 h后稳定。该方法简单灵敏准确,可以较好地满足厄贝沙坦原料药生产中基因毒性杂质NDMA和NDEA的检验。     

高效液相色谱法同时测定海珠喘息定片中槲皮素和山柰酚含量

目的 建立同时测定海珠喘息定片中主药胡颓子叶的指标性成分槲皮素和山柰酚含量的高效液相色谱法.方法 色谱柱为Shimadzu Shim-pack GIST-C18柱(250 mm×4.6 mm,5μm),流动相为甲醇-0.4％磷酸水溶液(50:50,V/V),流速为1.0 mL/min,柱温为30℃,检测波长为360 n...     

液相色谱-串联质谱法测定柏子仁中黄曲霉毒素残留量

目的建立检测柏子仁中黄曲霉毒素B1,B2,G1,G2残留量的液相色谱-串联三重四极杆质谱法。方法将样品提取液经免疫亲和柱净化,甲醇洗脱,以甲醇/乙腈-0.1 mmol乙酸铵为流动相,经反相色谱柱Agilent Zorbax Extend-C18柱(250 mm×4.6 mm,5μm),用电喷雾正离子二级离子监测扫描模式(MRM)检测。结果黄曲霉毒素G2和B2质量浓度在0.03～3.2 ng/mL范围内、黄曲霉毒素B1和G1在0.1～10 ng/mL范围内与峰面积积分值线性关系良好。检测限(LOD)为0.1 ng/mL,定量限(LOQ)为0.2 ng/mL。3个质量浓度(0.25,1.0,5.0 ng/mL)的加标平均回收率为84.1%～96.8%,RSD为7.7%～13.4%。结论所用方法专属性强、灵敏度高、简便快速、结果准确,可定性定量测定柏子仁中残留的黄曲霉毒素。     

Evaluation of solid-phase sorbents for the analysis of ropinirole in whole blood

In this paper, the extraction and analysis of ropinirole from whole blood using solid-phase cartridges is presented. Previously published methods for the analysis of this drug have employed plasma samples using C(18) cartridges. Liquid-liquid extraction has been employed for analysis of postmortem samples. In the method, drug free blood was spiked with ropinirole (0 to 10 ng) and an internal standard (quinidine). The samples were buffered with distilled water and centrifuged. The supernatant liquid was applied to previously conditioned endcapped C(6), C(18), and C(8)/SCX solid-phase extraction columns. The columns were washed, dried, and eluted with various solvents systems. The eluants were collected and evaporated. The residue was dissolved in 100 microL of aqueous 0.1% trifluoroacetic acid and analyzed by liquid chromatography using a C(18) (4.6 x 150 mm, 5-microm particle size) column and monitored at 250 nm, using diode-array detection. A mobile phase consisting of methanol/0.1% TFA in distilled water (22:78 v/v) was employed. The data was collected and appraised. It was found that 3-mL 200-mg CEC06 C6 (Hexyl endcapped) solid-phase columns that had been washed with 3 x 3 mL water and 3 x 3 mL acetonitrile and eluted with a solvent system consisting of 95:5 v/v acetonitrile/ammonia performed best. The linear range for this analysis was found to be from 0 to 10 ng/mL. The limit of detection was determined to be 1 ng/mL with a limit of quantification of 2.5 ng/mL.     

电感耦合等离子体-质谱法测定益肾壮骨丸中6种重金属含量

目的建立测定益肾壮骨丸中6种重金属元素含量的电感耦合等离子体-质谱(ICP-MS)法。方法射频功率为1 550 W,冷却气、辅助气流速分别为14.0,0.8 L/min,采样锥和截取锥为镍锥,重复次数为3次,采样模式为KED模式,蠕动泵转速为40 r/min,并加入内标元素校正响应信号波动。结果铅(Pb)、砷(As)、汞(Hg)、镉(Cd)、铜(Cu)、铬(Cr)元素质量浓度分别在0～20 ng/mL,0～20 ng/mL,0～2 ng/mL,0～10 ng/mL,0～500 ng/mL,0～100 ng/mL范围内与各待测元素/内标元素仪器信号强度线性关系良好(r> 0.995);检测限分别为0.029,0.005,0.016,0.001,0.022,0.022 ng/mL;多数元素精密度、重复性试验的RSD小于2.0%;平均加样回收率分别为88.03%,96.64%,83.75%,91.51%,95.63%,94.49%,RSD分别为6.99%,5.41%,3.68%,2.70%,1.87%,3.31%(n=6)。结论该方法灵敏、准确,可用于益肾壮骨丸中重金属元素Pb,As,...     

Determination of fentanyl in whole blood at subnanogram concentrations by dual capillary column gas chromatography with nitrogen sensitive detectors and gas chromatography/mass spectrometry

Two methods for the determination of fentanyl at subnanogram concentrations in whole blood have been developed and evaluated. The initial screening was by gas chromatography with nitrogen sensitive detection (GC/NPD) in a splitless injection onto two fused-silica, 0.32-mm i.d. capillary columns (5% and 50% phenyl methyl silicone). Confirmation was by gas chromatography/mass spectrometry (GC/MS) using selected ion monitoring of a splitless injection onto a 0.1-mm i.d., 0.34-microns 5% phenyl methyl silicone capillary column. The methods were studied at fentanyl concentrations over the range 0.05 to 5.0 ng/mL using 2 mL of blood. The detection limits were set at 0.10 ng/mL for GC/NPD and 0.05 ng/mL for GC/MS. The overall recovery of fentanyl was found to be greater than 75% over the range of 0.25 to 2.5 ng/mL. The within-run precision determined at fentanyl concentrations of 0.25 and 1.0 ng/mL showed coefficients of variation ranging from 8.7 to 14.8%. The between-run precision determined at concentrations of 0.4 and 0.8 ng/mL showed coefficients of variation ranging from 3.3 to 11.6%. The blood calibration curves in the range of 0.25 to 2.5 ng/mL monitored over a 3-month period showed a mean correlation coefficient of 0.99 for both the GC/NPD and GC/MS methods.     

Validation of the Immunalysis microplate ELISA for the detection of buprenorphine and its metabolite norbuprenorphine in urine

The purpose of this study was to validate the Immunalysis Buprenorphine Microplate enzyme-linked immunosorbent assay (ELISA) for the detection of buprenorphine in urine samples. Sixty-nine urine samples were obtained from volunteers on the Subutex treatment program and from routine samples submitted to the laboratory for buprenorphine testing. For ELISA analysis, samples were diluted 1:10 with K(2)HPO(4) (0.1M, pH 7.0). The limit of detection was calculated as 0.5 ng/mL buprenorphine. The intra-assay and interday precision was 3.8% (n = 10) and 8.6% (n = 50) respectively at 1 ng/mL buprenorphine. At a low concentration of norbuprenorphine (1 ng/mL), the immunoassay demonstrated a cross-reactivity of 78%. A higher cross-reactivity of 116% was observed at a higher concentration of norbuprenorphine (10 ng/mL). Dihydrocodeine, codeine, tramadol, morphine, propoxyphene, methadone, and EDDP were tested at concentrations of 10 ng/mL and 10,000 ng/mL and demonstrated no cross-reactivity with the assay. For liquid chromatography-tandem mass spectrometry (LC-MS-MS), deuterated internal standard mixture, 1M acetate buffer (pH 5.0), and b-glucuronidase were added to the standards and samples, which were then incubated for 3 h at 60 degrees C. After incubation, 3 mL K(2)HPO(4) (0.1M, pH 6.0) was added and the pH altered to pH 6.0 using 1M KOH. Buprenorphine and norbuprenorphine were subsequently extracted by solid-phase. Twenty-one samples were confirmed positive and 48 samples were confirmed negative by LC-MS-MS. Using a cut-off value of 0.5 ng/mL buprenorphine, the immunoassay demonstrated a sensitivity and specificity of 100%.     

Confirmation and quantitation of cocaine, benzoylecgonine, ecgonine methyl ester in human urine by GC/MS

A rapid, sensitive, reliable quantitative GC/MS method using 0.2 mL of urine was developed for the confirmation of cocaine use. After a simple organic solvent extraction and derivatization with pentafluoropropionic anhydride, cocaine, benzoylecgonine, and ecgonine methyl ester were identified by GC/MS through the retention time for the total ion current and selected ion monitoring (SIM) for each analyte. Quantitation was achieved by obtaining the calibration curves for the molecular ion ratios of the analyte/ketamine (IS) over a range of 12.5-250 ng/mL (0.1-2 ng total). The extraction efficiency for these analytes ranged from 70 to 82%. The sensitivity limit of detection for each analyte was 12.5 ng/mL (0.1 ng) at p less than 0.01. Intra- and interday precision for these analytes ranged between 14.7 and 29.5% CV. This method is in routine use in our laboratory for the GC/MS confirmation of enzyme immunoassay cocaine-positive urine samples.