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21.
Abstract: An LC–MS method was developed for benzylpiperazine (BZP) and trifluoromethylphenylpiperazine (TFMPP), constituents of “party pills” or “legal herbal highs,” and their metabolites in human blood plasma. Compounds were resolved using a mixture of ammonium formate (pH 4.5, 0.01 M) and acetonitrile (flow rate of 1.0 mL/min) with a C18 column. Calibration curves were linear from 1 to 50 ng/mL (R2 > 0.99); the lower limit of quantification (LLOQ) was 5 ng/mL; the accuracy was >90%; the intra‐ and interday relative standard deviations (R.S.D) were <5% and <10%, respectively. Human plasma concentrations of TFMPP were measured in blood samples taken from healthy adults (n = 6) over 24 h following a 60‐mg oral dose of TFMPP: these peaked at 24.10 ng/mL (±1.8 ng/mL) (Cmax) after 90 min (Tmax). Plasma concentrations of 1‐(3‐trifluoromethyl‐4‐hydroxyphenyl) piperazine peaked at 20.2 ng/mL (±4.6 ng/mL) after 90 min. TFMPP had two disposition phases (t½ = 2.04 h (±0.19 h) and 5.95 h (±1.63 h). Apparent clearance (Cl/F) was 384 L/h (±45 L/h).  相似文献   
22.
County-level crime data have major gaps, and the imputation schemes for filling in the gaps are inadequate and inconsistent. Such data were used in a recent study of guns and crime without considering the errors resulting from imputation. This note describes the errors and how they may have affected this study. Until improved methods of imputing county-level crime data are developed, tested, and implemented, they should not be used, especially in policy studies.  相似文献   
23.
Swedish public law has incorporated a general rule of public access to documents, and to information in the wider sense, since the Freedom of the Press Act of 1766. On the Community level, the relationship between Regulation (EC) 45/2001 on data protection and Regulation (EC) 1049/2001 on public access to documents exemplifies the tension between the public's interest in scrutinising the administration carried on in its name, and the integrity of the individual. However, a similar tension exists between Sweden's Personal Data Act of 1998, implementing Directive 95/46, and the Freedom of the Press Act. A misuse model of data protection law, by seeking to concentrate on serious rather than technical infringements of privacy, might serve to ease the tension. The views expressed in this article are solely those of the author and are not attributable to any Community institution. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
24.
On the basis of prior research findings that employed youth, and especially intensively employed youth, have higher rates of delinquent behavior and lower academic achievement, scholars have called for limits on the maximum number of hours per week that teenagers are allowed to work. We use the National Longitudinal Survey of Youth 1997 to assess the claim that employment and work hours are causally related to adolescent problem behavior. We utilize a change model with age-graded child labor laws governing the number of hours per week allowed during the school year as instrumental variables. We find that these work laws lead to additional number of hours worked by youth, which then lead to increased high school dropout but decreased delinquency. Although counterintuitive, this result is consistent with existing evidence about the effect of employment on crime for adults and the impact of dropout on youth crime.
Gary SweetenEmail:
  相似文献   
25.
Abstract:  Poisoning with superwarfarins, like bromadiolone, is a growing public health problem, and the mortality is high. Pharmacokinetic data on bromadiolone in humans are however scarce, and there are no reports following repeated exposures to bromadiolone. We have developed a method for quantification of bromadiolone in whole blood, using liquid chromatography–mass spectrometry (LC-MS). The analytical method is reported. Limit of detection was 0.005 mg/L and limit of quantification was 0.01 mg/L. The concentrations of bromadiolone in whole blood and plasma in serial samples from a 62-year-old woman were measured. The half-life of bromadiolone in blood was estimated to be about 6 days in the initial phase of elimination and about 10–13 days in the terminal phase. The mean plasma/blood ratio of bromadiolone was 1.7 ± 0.6. Stability testing of bromadiolone in whole blood samples after two cycles of freeze and thaw revealed that bromadiolone concentrations decreased.  相似文献   
26.
目的建立快速、灵敏的常见毒物的质谱自动筛选检测方法。方法建立常见毒物的质谱用户库,优化分离条件,优化质谱数据的自动分析参数,进行标样和样品分析。结果建立了含1306种常见毒物的质谱用户库;建立了自动筛选方法;得到了150种常见毒物的保留时间和检测限。结论建立的方法具有快速、灵敏、准确的优点,完全可替代繁杂的质谱检索手工操作。  相似文献   
27.
A solid-phase microextraction (SPME) procedure involving direct contact between the SPME fibers and the solid matrix and subsequent gas chromatography/mass spectrometric analysis for the detection of accelerants in fire debris is described. The extraction performances of six fibers (100 mum polydimethylsiloxane, 65 mum polydimethylsiloxane-divinylbenzene, 85 mum polyacrylate, 85 mum carboxen-polydimethylsiloxane, 70 mum Carbowax-divinylbenzene, and 50/30 mum divinylbenzene-Carboxen-polydimethylsiloxane) were investigated by directly immersing the fibers into gasoline, kerosene, and diesel fuel. For simulated fire debris, in the direct contact extraction method, the SPME fiber was kept in contact with the fire debris matrix during extraction by penetrating plastic bags wrapping the sample. This method gave comparable results to the headspace SPME method in the extraction of gasoline and kerosene, and gave an improved recovery of low-volatile components in the extraction of diesel fuel from fire debris. The results demonstrate that this procedure is suitable as a simple and rapid screening method for detecting ignitable liquids in fire debris packed in plastic bags.  相似文献   
28.
LC-MS/MS测定尿液中可卡因及其代谢物苯甲酰爱康宁   总被引:4,自引:0,他引:4  
Sun QR  Xiang P  Yan H  Shen M 《法医学杂志》2008,24(4):268-272
目的建立尿液中可卡因(cocaine,COC)及其代谢物苯甲酰爱康宁(benzoylecgonine,BZE)的液相色谱-串联质谱分析方法。方法尿液经固相萃取后,用AllurePFP丙基柱分离,以V(甲醇):V(20mmol/L乙酸胺和0.1%甲酸的缓冲溶液)=80∶20为流动相,采用二级质谱多反应监测模式检测COC和BZE。按10mg/kg的剂量对豚鼠腹腔注射可卡因,给药后收集7d尿液。结果尿液中COC和BZE在2.0~100ng/mL质量浓度范围内线性关系良好(r=0.9995),最低检测限(LOD)为0.5ng/mL;回收率大于90%;日内和日间精密度均小于6%;豚鼠尿液中主要检测目标物是BZE,且BZE检测时限也较COC长。结论所建方法灵敏度高,选择性好,适用于尿液中可卡因和苯甲酰爱康宁的检测。  相似文献   
29.
The investigation of the X-linked DNA markers are well established in the forensic routine case work. We studied an Ewe population sample from Ghana. The eight X-chromosomal STRs DXS10135, DXS8378, DXS7132, DXS10074, HPRTB, DXS10101, DXS10134 and DXS7423 were analyzed in 182 Ewe individuals (108 females and 74 males) from the region of Sogakofe (Ghana). Allele frequencies and statistical parameter as well as comparison with known data from Germans and with data from an Amharic population (Ethiopia) are presented.  相似文献   
30.
Two main approaches can be used for determining the age of an ink: indirect dating and direct dating. Indirect dating is based on the chemical analysis of an ink followed by comparison with known samples in a reference collection. The collection should contain information about the inks including the market introduction dates. This approach may allow for an anachronism to be detected. The second concept is based on measuring ink components that change with age. The analysis of solvents in ballpoint inks may be a useful parameter for determining the age of ink on paper. In a previous study, the authors demonstrated that thermal desorption of ink directly from paper, followed by chemical analysis using gas chromatography-mass spectrometry (GC-MS), is a promising procedure for characterizing ink-binder resins and solvents. Preliminary tests showed that monitoring the evaporation of ink solvent from ink on paper is not a suitable method for ink dating. Thermal analysis of ink on paper in two steps revealed that fresh ink releases a relative amount of solvent at a certain low temperature in a defined period of time, which decreases as the ink ages. As a consequence, this relative amount of solvent released at a certain low temperature, and its decrease with time, can be used to estimate ink age. This age-dependent parameter was studied in 85 different inks ranging in age from 1 week to 1.5 years. It was found that some inks showed a significant decrease of this parameter up to an age of several months, and that the aging process can be monitored within this period. For other inks, however, the age-dependent parameter decreases relatively fast, e.g., within a few days, to a constant level, which can be too fast for casework. Based on these results, a general procedure for assessing the age of ballpoint pen inks on paper was developed.  相似文献   
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