Ink Dating Using Thermal Desorption and Gas Chromatography/Mass Spectrometry: Comparison of Results Obtained in Two Laboratories

An ink dating method based on solvent analysis was recently developed using thermal desorption followed by gas chromatography/mass spectrometry (GC/MS) and is currently implemented in several forensic laboratories. The main aims of this work were to implement this method in a new laboratory to evaluate whether results were comparable at three levels: (i) validation criteria, (ii) aging curves, and (iii) results interpretation. While the results were indeed comparable in terms of validation, the method proved to be very sensitive to maintenances. Moreover, the aging curves were influenced by ink composition, as well as storage conditions (particularly when the samples were not stored in “normal” room conditions). Finally, as current interpretation models showed limitations, an alternative model based on slope calculation was proposed. However, in the future, a probabilistic approach may represent a better solution to deal with ink sample inhomogeneity.     

Simultaneous Screening for 45 Poisonous Alkaloids in Blood by LC-MS/MS

Objective To develop a liquid chromatography-tandem mass spectrometry(LC-MS/MS) screening method for 45 poisonous alkaloids in blood. Methods Identification was based on the compound’s retention time and two precursor-to-production transitions. The method involved a liquid-liquid extraction(LLE) followed by LC-MS/MS with multiple-reaction monitoring(MRM). When 1 m L of blood was extracted with diethyl ether at p H=9.2 with SKF525 Aas the internal standard, the target compounds were analyzed with LC-MS/MS in the positive ionization mode. Results The target alkaloids had good linearity(r>0.995 1), both the intra-day precision and inter-day precision being less than 14.77%. The limits of detection ranged from 0.05 to 25 ng/m L in blood. Conclusion The method is selective and sensitive in detecting poisonous alkaloids with a total running time of 12 minutes; therefore it was successfully applied to some actual cases of suspected alkaloids poisoning.     

利用扫描电镜/能谱仪和X-射线衍射仪鉴别假“冰毒”

冰毒为纯白或淡黄色结晶体,为利益所驱,很多制贩毒者利用其它外观相似的晶体充当替代品或者掺杂剂,在常规检测时,用气/质联用仪无法检验其成分。本文利用扫描电镜/能谱仪和X-射线衍射仪对外观酷似"冰毒"的晶状物成分进行检测,先利用扫描电镜/能谱仪测定未知物主要元素,再利用X-射线衍射仪测定其晶体结构和成分。两者有效结合成功地鉴别假"冰毒"物质的成分。     

顶空进样-气相色谱-质谱法测定芪白平肺胶囊中挥发性成分

目的 测定芪白平肺胶囊中挥发性成分。方法 采用顶空进样-气相色谱-质谱联用技术,并通过所用质谱库检索研究其挥发性化学成分组成,用面积归一化法确定各成分的相对百分含量。结果 共分辨出68个色谱峰,鉴定出53个化学成分,约占总挥发性成分含量的90.75%,主要挥发性成分为酯类(38.58%)、酸类(22.97%)、杂环类(13.54%)、醛类(8.75%)、醇类(2.84%)、醚类(2.71%)、芳烃类(0.74%)和酮类(0.62%)物质,其中含量最高的是乙酸乙酯(25.54%),其次为乙酸(11.79%),含量较高的为2-甲基丁醛(7.00%),2-氨基丁酸(6.83%),乙酸丙酯(5.60%),2,3-二羟基丙酸(3.45%),糠醛(3.08%),5-甲基糠醛(3.05%),2-甲基四氢呋喃-3-酮(2.82%),2-乙酰基呋喃(2.54%),甲基环氧丙烷(2.03%),等。结论 所建立的方法分离效果较好,能够准确鉴定芪白平肺胶囊中主要挥发性成分。     

液相色谱-质谱联用法测定复方氨酚烷胺胶囊人体生物等效性

目的 研究复方氨酚烷胺胶囊的人体生物等效性。方法 采用双周期交叉实验设计,22名健康男性受试者随机交叉单剂量口服复方氨酚烷胺胶囊试验制剂和参比制剂各1粒。采用液相色谱-质谱联用法测定血浆中对乙酰氨基酚（paracetamol, PAR）、金刚烷胺（amantadine, AMA）、马来酸氯苯那敏（chlorphenamine, CHL）和咖啡因（caffenine, CAF）的浓度,采用DAS3.2.5软件计算药物代谢动力学参数,并采用双侧t检验法和90%置信区间比较主要药物代谢动力学参数（cmax,tmax,t1/2和AUC0-t）。结果 受试制剂和参比制剂中PAR、AMA、CAF和CHL的AUC0→t、AUC0→∞、cmax和tmax比较,差异均无统计学意义（P>0.05）。结论 本实验方法准确、灵敏、简便,两种制剂具有生物等效性。     

石台县虎杖药材及其根际土壤中硒及重金属元素含量检测与相关性分析

目的 测定石台县虎杖药材及其根际土壤中Se和重金属Pb、Cd、As、Hg、Cu的含量,并对其相关性进行分析。方法 采用电感耦合等离子体质谱技术测定Se和重金属Pb、Cd、As、Hg、Cu的含量,并对其相关性进行分析。结果 石台县7个乡镇虎杖药材中Se、As、Cu、Cd、Pb、Hg的平均含量分别为0.59、0.32、7.42、0.12、1.38、0.005 mg/kg;根际土壤中Se、As、Cu、Cd、Pb、Hg的平均含量分别为2.34、65.77、44.65、0.95、111.61、0.22 mg/kg。结论 石台县虎杖药材及其根际土壤皆达富硒水平,且虎杖药材与其根际土壤中硒含量呈正相关;但虎杖药材与其根际土壤中As、Cu、Cd、Pb、Hg等重金属元素的含量不具相关性;石台县7个乡镇虎杖药材重金属含量均低于国家限量标准,具有较高的安全性。     

左归饮水提物对大鼠Cyp2b1、Cyp2c11、 Cyp2c7亚酶活性的影响

目的 采用Cocktail探针药物法评价左归饮对大鼠体内细胞色素氧化酶P450亚型酶Cyp2b1、Cyp2c11和Cyp2c7代谢活性的影响,为左归饮的开发应用提供实验依据。方法 选用阿莫地喹、安非他酮、奥美拉唑分别作为Cyp2b1、Cyp2c11和Cyp2c7的探针底物,制备成Cocktail混合溶液。将SD雄性大鼠分为实验组和空白组,实验组每日清晨灌服高、中、低剂量左归饮溶液,空白组每日清晨灌服空白溶剂,均连续给药14 d。第14天清晨尾静脉注射混合探针药物后于各时间点测定大鼠体内探针药物的血药浓度。经DAS 2.0软件计算探针药物的药物代谢动力学参数,评价左归饮对大鼠体内代谢酶活性的影响。采用LC-MS/MS法同时测定3种探针药物的血药浓度。结果 与空白组比较,高、中、低剂量左归饮连续给药对Cyp2b1、Cyp2c7和Cyp2c11酶活性的影响均无统计学意义（P＞0.05）。结论 左归饮配伍其他药物使用对代谢酶无明显影响,左归饮可在临床上广泛地配伍应用。     

Phenobarbital in hair and drug monitoring

Phenobarbital analysis was performed in vertex hair of patients by gas chromatography mass spectrometry (GC/MS). After washing with dichloromethane, about 250 mg were ground to dust in a ball mill. A 50-mg sample was stirred mechanically for 10 min with 3 ml of NH₄Cl/HCl buffer (pH 2.0) containing phenobarbital D₅. A solid phase extraction was performed (extrelut Merck) and elution was achieved with chloroform/isopropanol/n-heptane (50:17:33; v/v). A full scan (40–240 uma) acquisition was realized by GC/MS with an ion trap (ITD 700 Finnigan) using a DB5-MS chromatographic column. Quantification was achieved by integrating dominants ions (phenobarbital, 204; phenobarbital D₅, 209). Compared to serum, hair concentrates phenobarbital during anti-epileptic therapy (average value 36.4 ng/mg, n = 40 vs. 18.7 mg/l, n = 23). A group correlation exists between phenobarbital in hair and phenobarbital in serum, and between phenobarbital in hair and clinic observation in some typical cases. Phenobarbital in hair yields good information over a long period, especially when blood collection has not been made, when clinical disorders are observed on long-term therapeutic observance.     

Nails as useful materials for detection of methamphetamine or amphetamine abuse

Methamphetamine and amphetamine could be demonstrated in nail clippings obtained from methamphetamine users by sensitive gas chromatography/chemical ionization mass spectrometry with N-methylbenzylamine as an internal standard. The methamphetamine levels in fingernails were comparable to those in hair. Both stimulants were more concentrated in toenails than in fingernails. The detection of methamphetamine and amphetamine in nails provides an alternative informatian to that in hair on their past abuse.     

生物样品中的金属毒物电感耦合等离子发射光谱检验

目的建立有毒金属元素在肝、脾和肾脏组织中的快速检测方法。方法通过模拟样品,采用微波消解炉对样品进行预处理,用电感耦合等离子发射光谱仪同时对多种可疑有毒金属元素进行检测。结果在中毒剂量,对肝脏和肾脏组织中的可疑毒金属元素,可以采用电感耦合等离子发射光谱仪进行检测。