Detection and Analysis of Blood Dexmedetomidine in Drug-Facilitated Cases.

OBJECTIVES: To establish a simple and rapid qualitative and quantitative detection method of dexmedetomidine in blood. METHODS: Blood was separated on the Allure PFP Propyl liquid chromatography column with isocratic elution after it was precipitated by acetonitrile and filtered. Qualitative and quantitative analysis of dexmedetomidine was performed using positive ion scan mode and multi-reaction monitoring mode. RESULTS: The limit of detection of dexmedetomidine in blood was 0.2 ng/mL and the limit of quantification was 0.5 ng/mL. The linearity of the method was good in the range of 0.5-1 000 ng/mL, and the correlation coefficient was greater than 0.99. The accuracy of the method was 90.34%-112.67% and the extraction recovery was 50.05%-91.08%, with no significant matrix effect. CONCLUSIONS: This method is simple, selective and suitable for the qualitative and quantitative analysis of dexmedetomidine in blood, which can provide a reference for drug-facilitated cases involving dexmedetomidine.

Forensic Analysis of 9 Poisoning Death Cases Caused by Oral Administration of Diphenidol.

OBJECTIVES: To analyze the characteristics of diphenidol poisoning cases and to provide clues and technical means for the identification of such cases. METHODS: Biological samples of 9 deaths caused by diphenidol poisoning were detected by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), and the characteristics of these cases were analyzed retrospectively. RESULTS: Most of the deaths caused by diphenidol poisoning were young females. The dosage was between 60 and 300 tablets, and the mass concentration of diphenidol in the postmortem blood ranged from 0.87 to 99.00 µg/mL. There was no correlation between the dosage and the concentration of diphenidol in the blood. CONCLUSIONS: Diphenidol poisoning has the characteristics of high concealment and lethality. More attention should be paid to suicide cases, and diphenidol should be recommended as a routine detection item to avoid missing detection.

Strategies for Collection and Analysis of Samples in Simple Asphyxiant Gas Acute Poisoning Death Cases.

At present, the death cases of simple asphyxiant gas acute poisoning are increasing sharply. Common asphyxiant gases in death cases include nitrogen, helium, carbon dioxide, methane, propane, laughing gas, etc. Simple asphyxiant gas has no affinity for biological matrices and escapes quickly, which puts forward new requirements for autopsy procedures, selection and collection of samples, laboratory analysis and identification. This paper reviews the research and development process of death cases caused by simple asphyxiant gas acute poisoning and put forwards the collection and analysis strategy of the samples in such cases. The most valuable biological samples in such cases should be lung tissues associated with the airways, followed by brain tissue and cardiac blood. Gaseous samples from the esophageal cavity, tracheal cavity, pulmonary bronchi, gastric and cardiac areas are also recommended as valuable samples. In the case of postmortem examination, the gas should be injected into gas sample bag directly. Biological materials such as tissue and blood should be directly sealed in head-space vials and analyzed by using the headspace gas chromatography-mass spectrometry.

Analysis of the Distribution of Total Phosphine and the Characteristics of Phosphine Poisoning in 29 Victims.

OBJECTIVES: To study the distribution of total phosphine in phosphine poisoning victims and summarize the characteristics of phosphine poisoning cases. METHODS: The phosphine and its metabolites in the biological samples of 29 victims in 16 phosphine poisoning cases were qualified and quantified by headspace gas chromatography-mass spectrometry. RESULTS: Five victims among 29 were poisoned by ingestion of aluminium phosphide and 24 by inhalation of phosphine gas. Phosphine metabolites were detected in the biological samples of 23 victims, and the concentrations of total phosphine in blood ranged 0.5-34.0 µg/mL. The total concentration of phosphine in liver tissue was up to 71.0 µg/g. Phosphine was not detected in the blood of the other six survived victims, which may be related to the small amount of phosphine exposure and the delay in blood sampling. CONCLUSIONS: The total concentration of phosphine in blood and tissues caused by aluminum phosphine ingestion is higher than that caused by phosphine gas inhalation. The death cases of phosphine inhalation are characterized by long exposure time, repeated exposures and age susceptibility.

[Analysis of GHB and Its Precursors in Urine and Their Forensic Application].

OBJECTIVE: To establish the method to analyze γ-hydroxybutyric acid (GHB) and its precursors 1,4-butanediol (1,4-BD) and gamma-butyrolactone (GBL) in urine through LC-MS/MS and provide evidence for related cases. METHODS: GHB-d6 and MOR-d3 were used as the internal standard. The urine sample was separated by LC after protein precipitation with methanol. The electrospray ion source was for ionization. Each compound was detected through multiple-reaction monitoring (MRM) mode. RESULTS: The limits of detection of GHB and its precursors 1,4-BD and GBL were 0.1, 0.1 and 2 µg/mL. The accuracy was 87.6%-98.1%. The intra-day and inter-day precisions were less than 15% and matrix effects were higher than 80%. CONCLUSION: The method is high sensitive, simple, rapid, specific and with high reliability. This study has provided technical support and basic data for forensic cases involving GHB.

Chlorpyrifos Determined in Human Blood by UPLC-MS/MS and Its Application in Poisoning Cases.

OBJECTIVE: To determine the chlorpyrifos in human blood by liquid chromatography-tandem mass spectrometry and to validate its application in poisoning cases. METHODS: The samples were extracted by a simple one-step protein precipitation procedure. Chromatography was performed on a Capcell Pack C18 MGII column (250 mm x 2.0 mm, 5 µm) using an isocratic elution of solvent A (0.1% formic acid-water with 2 mmol/L ammonium acetate) and solvent B (methanol with 2 mmol/L ammonium acetate) at 5:95 V:V). RESULTS: The linear ranged from 5 to 500 ng/mL (r = 0.998 7). The limit of detection (LOD) and the lower limit of quantification (LLOQ) were 2 ng/mL and 4 ng/mL, respectively. For this method, the precision and accuracy of intra-day and inter-day were < 10% and 97.44%-101.10%, respectively. The results in stability test of long-term frozen were satisfied. The matrix effect, recovery and process efficiency were 64.97%-86.81%, 76.70%-85.52%, and 55.57%-66.58%, respectively. CONCLUSION: This method can provide a rapid approach to chlorpyrifos extraction and determination in toxicological analysis of forensic and clinical treatment.

Method development and validation for determining 1,3-butadiene in human blood by gas chromatography-mass spectrometry and head-space gas chromatography.

To develop a simple, validated method for identifying and quantifying 1,3-butadiene (BD) in human blood by gas chromatography-mass spectrometry (GC-MS) and head-space gas chromatography (HS-GC). BD was identified by GC-MS and HS-GC, and quantified by HS-GC. The method showed that BD had a good linearity from 50 to 500 microg/mL (r > 0.99). The limits of detection and quantification were 10 microg/mL and 50 microg/mL, respectively. Both the intra-day precision and inter-day precision were < 6.08%, and the accuracy was 96.98%-103.81%. The method was applied to an actual case, and the concentration of BD in the case was 242 microg/mL in human blood. This simple method is found to be useful for the routine forensic analysis of acute exposure to BD.

[Screening and confirmation of psychotropic drugs in blood and urine by HPLC-LTQ Orbitrap MS].

OBJECTIVE: To establish a screening and confirmation method for psychotropic drugs and their metabolites in human blood and urine by HPLC-LTQ Orbitrap MS. METHODS: The samples were pretreated with Sirocco protein precipitation plate, and then analyzed by HPLC-LTQ Orbitrap MS. The method was validated in terms of the limit of detection (LOD). An accurate mass database was created for psychotropic drugs screening. RESULTS: The LOD for most of 56 determined compounds was < or = 0.1 ng/mL. The accurate mass database included the accurate mass information of 61 psychotropic drugs. CONCLUSION: The method is accurate, rapid, sensitive and the database is suitable for psychotropic drugs screening and confirmation.

[Measurement of acetonitrile in blood and urine by head-space gas chromatography].

OBJECTIVE: To establish the method for measurement of acetonitrile in blood and urine by head-space gas chromatography. METHODS: DB-ALC1 (30 m x 320 microm x 1.8 microm) and DB-ALC2 (30 m x 320 microm x 1.2 microm) capillary column were used to measure the acetonitrile in blood and urine with the isopropanol as internal standard reference. RESULTS: The limits of detection of acetonitrile in both blood and urine were 0.5 microg/mL, with a linear range of 5-1000 microg/mL (r = 0.999).The accuracy of this method was 93.2%-98.0%. The RSD for the intra-day and inter-day were less than 3.7%. CONCLUSION: The method is capable for measurement analysis of acetonitrile in blood and urine.

[Determination of Hg in biological samples by inductively coupled plasma mass spectrometry].

OBJECTIVE: To establish an inductively coupled plasma mass spectrometry (ICP-MS) method for determination of Hg in biological samples. METHODS: The samples were digested with microwave digestion instrument. ICP-MS was applied to detect Hg in blood, urine and hair specimens by using 115In as an internal marker. The ability of gold to eliminate the memory effect of mercury was investigated with the gold amalgamate produced by gold and mercury. RESULTS: The limits of detection were in the 0.01 microg/L, and the accuracy of the method ranged from 97.0% to 107.1%. The concentration of gold was 10 microg/L and the memory effect of mercury was resolved. CONCLUSION: The method is accurate, rapid, sensitive and suitable for the cases of mercury poisoning and the clinical diagnosis and monitoring for patients with mercury poisoning.

[Simultaneous determination of sixteen antibiotics in human urine with ultra performance liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To develop a method for simultaneous determination of sixteen antibiotics in human urine by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). METHODS: With Piperacillin as an internal standard, the target antibiotics in urine samples were enriched and purified by Oasis HLB solid phase extraction (SPE) cartridges, then separated in a ZORBAX SB-C18 column with a gradient elution of mobile phase of 0.1% formic acid water and acetonitrile, finally analyzed with multiple reaction monitoring (MRM) mode. RESULTS: The limits of detection (LOD) for these sixteen antibiotics were in the range of 0.05-10.0 ng/mL and the limits of quantification (LOQ) in the range of 0.25-20.0 ng/mL. Within the related linear range, the related coefficient (r) of sixteen antibiotics were all more than 0.995. Accuracies for these antibiotics were ranged from 82.0%-119.3%, the within-day precision were less than 13.9%. CONCLUSION: The developed method is sensitive, specific and appropriate for the analysis of antibiotics in forensic toxicology and therapeutic drugs monitoring.

[Application of liquid chromatography-high resolution mass spectrometry in toxicological screening].

Due to the diversity of toxicologically relevant substances, the uncertainty of target compounds and the specificity of samples, toxicological screening techniques have always been valued by the forensic toxicologists. Depending on its powerful separation ability, superhigh resolution and accurate mass measurement, combined with the two levels spectrum database matching and abundance ratio of isotope ion, the liquid chromatography-high resolution mass spectrometry (LC-HRMS) analyzers have increasingly advantage in screening and identification of chemical compound. This review focuses on the applications of LC-HRMS in screening and identification of drug-of-abuse, prescription drugs, pesticide and stimulant. The prospect of LC-HRMS in forensic toxicology analysis is also included.

[Determination of ethyl glucuronide in blood and urine by LC-MS/MS].

OBJECTIVE: To develop a method for determining ethyl glucuronide (EtG) in blood and urine by liquid chromatograph coupled with tandem mass spectrometer (LC-MS/MS). METHODS: After blood and urine de-proteined by acetonitrile, the supernate obtained from a centrifuge was analyzed by LC-MS/MS. RESULTS: Determination limit of EtG in both blood and urine was 0.05 pg/mL, with a linear range of 0.10-5.00 microg/mL (r > 0.999). Accuracy in both matrixes was 95%-109%. Inter- and intra-day RSD were less than 12%. The method showed an excellent performance when it was used to analyze authentic blood and urine samples for EtG. CONCLUSION: The method is capable for blood and urine EtG analysis.

[Simultaneous determination of opioid compounds in human urine by UPLC-MS/MS].

OBJECTIVE: To propose a method for simultaneous determination of codeine(COD), 6-monoacetyl-morphine (6-MAM), morphine (MOR), morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) in human urine by ultra performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS). METHODS: After precipitation of protein by acetonitrile, the urine samples, with added the morphine-d3 (MOR-d3) and morphine-3-Glucuronide-d3 (M3G-d3) as internal standards, were pre-treated by Sirocco protein precipitation plate, and then analyzed by UPLC-MS/MS. RESULTS: The limit of detection was 0.2 ng/mL for both COD and MAM, the limit of quantitation was 0.5 ng/mL for both COD and MAM. The limit of detection was 0.5 ng/mL for MOR, M3G and M6G, the limit of quantitation was 1 ng/mL for them. The linear correlation coefficients were not less than 0.9997, both the inter-day and intra-day precisions were less than 10%, the recoveries were in the range of 70.0% to 98.3%, the matrix effects were about 50.5% to 99.0%. CONCLUSION: This proposed method is simple, rapid and accurate, it could be applied in forensic toxicological analysis.

[Determination of TTX in biological samples by LC-MS/MS].

OBJECTIVE: To propose a method for determination of tetrodotoxin (TTX) in human blood, urine and liver by liquid chromatography with tandem mass spectrometry (LC-MS/MS). METHODS: Solid phase extraction is used after the samples are precipitated, then the samples will be analyzed by LC-MS/MS. RESULTS: The limits of detection were 2 ng/mL in blood and urine and 4 ng/g in liver for TIX respectively, the linear correlation coefficients were not less than 0.9973, both of the intra-day and inter-day precisions were less than 12.80%, the recoveries for all kinds of specimens were more than 47.2%. CONCLUSION: This method is efficient, sensitive and accurate and was successfully validated for implementation in forensic toxicological analysis.

[Detection and application of ethyl glucuronide in forensic toxicology].

Ethyl glucuronide is a specific metabolite of ethanol. There have been plenty of articles referring its pharmacokinetics, detection and application as a specific bio-marker of alcohol intake. This article reviews various analytical methods of EtG, relationship between EtG quantification and ethanol intake, and criteria for determining chronic alcohol abuse, and origin of ethanol found in the cadavers by EtG analysis. EtG has its potential application in forensic toxicology.

[Determination of ethyl glucuronide in blood by GC-MS/MS].

OBJECTIVE: To develop a method for determining ethyl glucuronide(EtG) in human blood with gas chromatograph-tandem mass spectrometry (GC-MS/MS). METHODS: Human blood protein was precipitated with acetonitrile. The supernatant was transferred and air flow dried after centrifugated. The residue was derived with N, O-bis (trimethylsilyl)trifluoroacetamide (BSTFA), and analyzed with GC-MS/MS. RESULTS: The detection limit of EtG in blood was 0.05 microg/mL. Calibration curve covered a span from 0.1-10 microg/mL with a good linear relationship (r = 0.999 9). The method showed a excellent performance when was used to authentic blood sample analysis for EtG. CONCLUSION: The method is suitable for blood EtG analysis.

[The relation of blood alcohol concentration and neurobehavioral functions after drinking].

OBJECTIVE: To research the relation between blood alcohol concentration (BAC) and neurobehavioral function after drinking. METHODS: The neurobehavioral ability index (NAI) of 233 volunteers were measured with computer-administered neurobehavioral evaluation system-Chinese3 (NES-C3). RESULTS: The NAI of simple visual reaction time and mental arithmetic declined when BAC was more than 0.157 mg/mL, the NAI of benton visual retention, length discrimination and digit cancel declined significantly when BAC was more than 0.204 mg/mL. CONCLUSION: The neurobehavioral function declined significantly when BAC increased and recovered gradually when BAC declined due to the elimination of alcohol in blood.

[Research of on the stability of ethanol in preservation of ethanol in blood].

OBJECTIVE: To focus on the main factors that may influence the stability of ethanol in blood then try to establish the best conditions for preserving ethanol in blood. METHODS: Four crucial parameters, including temperature (-20, 4, 20 degrees C), preservative (NaF, No preservative, Na2O2), percentage of air chamber in container (0%, 25%, 50%), and ethanol concentration in blood (0.2, 0.8, 2.0 mg/mL) were investigated. Blood samples were stored under different conditions designed by orthogonal design L, (3(4))method. Quantification of ethanol in blood was carried out by headspace gas chromatography with FID detector. The results were statistically evaluated by analysis of variance. RESULT: Significant changes of ethanol concentrations were observed in the samples stored in 20 degrees C without any reserveative, while there were no obvious changes in the samples under other storage conditions. CONCLUSION: The best condition for keeping ethanol in blood stable is 4 degrees C with preservative and with 50% of air chamber in container. The temperature is main effective factor in the four factors.

[Simultaneous screening for 22 poisonous alkaloids in blood by liquid chromatography-tandem mass spectrometry with multiple-reaction monitoring].

OBJECTIVE: To establish a liquid chromatography-tandem mass chromatography (LC-MS/MS) method for the simultaneous screening for 22 poisonous alkaloids in blood. METHODS: This method involves a liquid-liquid extraction (LLE) followed by liquid chromatography-tandem mass spectrometry with multi-ple-reaction monitoring (MRM). After blood was extracted with buprenorphine as the internal standard, the target compounds were analyzed with LC-MS/MS-ESI in the positive ionization mode. RESULTS: Identification was based on the compound's retention time and two precursor-to-product ion transitions. The limits of detection ranged from 0.1 ng/mL to 20 ng/mL in blood. CONCLUSION: The method was sufficiently selective and sensitive to detect poisonous alkaloids and can be applied in forensic and clinical toxicology.