Determination of 12 herbal compounds for estimating the presence of Angelica Gigas Root, Cornus Fruit, Licorice Root, Pueraria Root, and Schisandra Fruit in foods by LC-MS/MS.

A wide variety of plant raw materials thought to promote health are used as herbal medicines as well as foods. However, there is no legal maximum or minimum concentration limit on any herbal compound when these plant raw materials are used in processed foods. Legally, these processed foods are regulated only for harmful substances, and there is no other guarantee of their contents. Therefore, the objective of this study was to determine the concentrations of 12 herbal compounds (nodakenin, decursin, decursinol angelate, morroniside, loganin, glycyrrhizic acid, liquiritigenin, puerarin, daidzin, schisandrin, gomisin A, gomisin N) in commonly used plant raw materials, such as "Angelica Gigas root", "Cornus Fruit", "Liquorice Root", "Pueraria Root", and "Schisandra Fruit"; and also in 45 processed foods, using high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). Method validation was performed successfully using the parameters of specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, precision, matrix effect, extraction recovery, and stability. The 12 herbal compounds were determined to be present in all the foods advertised as containing each ingredient, although in very low concentrations in some cases. Three solid samples labelled as 100% pure material from one herbal species also contained herbal compounds found in others, so that intentional or unintentional adulteration was suspected.

Monitoring urinary testosterone and epitestosterone levels, and their ratio, in Korean chemical castration subjects using liquid chromatography-tandem mass spectrometry.

In Europe, chemical castration has been adopted as a treatment for paraphilia since the 1930s. Among the various chemical castration agents, luteinizing hormone-releasing hormone (LHRH) agonists are now used widely because of their effectiveness and safety. In South Korea, a legislation of chemical castration to control the sexual impulses of sexual offenders was enforced in July 2011. Most of these subjects are treated with leuprorelin acetate, an LHRH agonist, for chemical castration. Despite this, there are few studies that address the long-term influence of LHRH agonists on testosterone (T) and epitestosterone (E) levels in chemical castration subjects. In order to analyze the urinary levels of T in chemical castration subjects, whose T levels are extremely low, we developed and validated an analytical method for the detection of both T and E in human urine using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) system. The urine samples were hydrolyzed, extracted, and analyzed by LC-MS/MS with electrospray ionization in the positive-ion mode. The limits of detection were 0.02 ng/mL and the limits of quantitation were 0.05 ng/mL, which provided great sensitivity. The established method was applied to urine samples from chemical castration subjects and healthy male volunteers. The chemical castration subjects showed significantly lower urinary T levels than the control subjects. In addition, the urinary E levels were also lower in the chemical castration subjects; however, the T/E ratios were constant and did not show a notable decrease because of the simultaneous decrease in both urinary T and E. The urinary T levels and T/E ratio did not exceed the doping control criteria for exogenous T ingestion for any subject. This study shows the trend of urinary T and E levels in long-term treated chemical castration subjects by establishing a highly sensitive LC-MS/MS method, that provides useful information for monitoring chemical castration.

Simultaneous determination of synthetic cannabinoids and their metabolites in human hair using LC-MS/MS and application to human hair.

Hair is one of the key samples for judging drug abuse in the field of forensic science. However, few studies have examined synthetic cannabinoids and their metabolites in human hair. Synthetic cannabinoids are a class of chemicals that bind to cannabinoid receptors, but they differ structurally from the cannabinoids found in cannabis. They have been sold sprayed on dried, shredded plant material under brand names such as "Spice" since the 2000s. In South Korea, synthetic cannabinoids have been widely distributed since 2009 and many types detected up to now. Unlike traditional drugs such as methamphetamine and cannabis, the abuse trends of synthetic cannabinoids were variable by regions and changed according to the times. If new types of synthetic cannabinoids become popular which has been altered in some structures, it becomes difficult to identify using exist analytical method. Therefore, it is important to develop a new analytical method for synthetic cannabinoids currently being abused in society. In this study, we developed simultaneous analytical methods for the detection of 18 synthetic cannabinoids and 41 of their metabolites in authentic human hair samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Selectivity, linearity, limits of detection (LODs), limits of quantification (LOQs), precision, accuracy, matrix effect, recovery, and process efficiency were evaluated, and all results were acceptable. Additionally, the distribution of synthetic cannabinoids in the head hair of Korean drug abusers from 2016 to 2018 was investigated. Hair samples from 43 individuals suspected of synthetic cannabinoid use were provided by law enforcement agencies. The drugs detected most prevalently in the head hair of Korean drug abusers were AB-CHMINACA and JWH-210.

Comparison of Physicochemical Characteristics of Garlic Produced from South Korea and China.

Garlic is widely cultivated and frequently used as a spice in South Korea, due to its characteristic flavor. It is rich in sulfur-containing compounds (for example, allicin) and nonsulfur elements (for example, phosphorus and potassium). During the last few years, the cultivation area of garlic in South Korea has gradually decreased, one of the reasons being the increase in low-priced imported garlic from China. Several studies have reported the discrimination of foods originating from different geographical areas by analyzing their physicochemical properties using various statistical methods. In this study, the differentiation of geographical origin of garlic between South Korea (60 samples) and China (41 samples) was performed by analyzing their physicochemical properties (for example, pH, soluble solid, moisture, free sugars, mineral elements, total flavonoid, and total phenolic contents) combined with statistical methods. The significant difference between domestic garlic from South Korea and imported garlic from China was investigated in terms of pH, moisture content, total flavonoid content, and all trace minerals except for manganese and magnesium. Logistic regression analysis was performed to determine the geographical origin (South Korea or China) of garlic after selecting the appropriate independent variables. As a result, the calculated logistic regression equation from the analysis of copper, iron, phosphorus, zinc, and sucrose contents could be used to determine whether the geographical origin of garlic was South Korea or China. PRACTICAL APPLICATION: Despite being widely used in South Korea, the cultivation area of garlic in South Korea has gradually decreased over the last few years. One of the reasons is the increase in low-priced imported garlic from China. To discriminate the geographical origin of garlic between South Korea and China, analyzed physicochemical properties (that is, Cu, Fe, P, Zn, and sucrose contents) of garlic in combination with logistic regression analysis can be helpful for scientists working on food forensics. This discrimination technique can help to maintain the quality of garlic and prevent economic fraud by confirming the authenticity of garlic from South Korea.

In Vitro Metabolism of 25B-NBF, 2-(4-Bromo-2,5-Dimethoxyphenyl)-N-(2-Fluorobenzyl)ethanamine, in Human Hepatocytes Using Liquid Chromatography⁻Mass Spectrometry.

25B-NBF, 2-(4-bromo-2,5-dimethoxyphenyl)-N-(2-fluorobenzyl)ethanamine, is a new psychoactive substance classified as a phenethylamine. It is a potent agonist of the 5-hydroxytryptamine receptor, but little is known about its metabolism and elimination properties since it was discovered. To aid 25B-NBF abuse screening, the metabolic characteristics of 25B-NBF were investigated in human hepatocytes and human cDNA-expressed cytochrome P450 (CYP) and UDP-glucuronosyltransferase (UGT) enzymes using liquid chromatography⁻high resolution mass spectrometry. At a hepatic extraction ratio of 0.80, 25B-NBF was extensively metabolized into 33 metabolites via hydroxylation, O-demethylation, bis-O-demethylation, N-debenzylation, glucuronidation, sulfation, and acetylation after incubation with pooled human hepatocytes. The metabolism of 25B-NBF was catalyzed by CYP1A1, CYP1A2, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP2J2, CYP3A4, and UGT2B7 enzymes. Based on these results, it is necessary to develop a bioanalytical method for the determination of not only 25B-NBF but also its metabolites in biological samples for the screening of 25B-NBF abuse.

Determination of boldenone in postmortem specimens including blood and urine samples using LC-MS/MS.

Boldenone (BOLD), one of androgenic anabolic steroids (AAS), although banned in humans, is still available illegally. AAS abuse has previously been associated with various cardiovascular adverse events including acute myocardial infarction, arrhythmia, and sudden death. In this study, the concentration of BOLD was determined in postmortem specimens from the corpse of a human male who intentionally injected BOLD undecylenate into his shoulder muscle. In addition, the endogenous levels of BOLD in the blood and urine samples of young human males have been reported. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with solid-phase extraction (SPE) was developed and validated for the analysis of BOLD in blood, muscular tissue and urine samples. The validation parameters including linearity, accuracy, precision, matrix effect, and recovery were satisfactory. The concentrations of BOLD in the blood of 20 young human males who didn't take BOLD were under the limit of quantitation (LOQ, 0.5 ng/mL). Additionally, the mean level of BOLD in the urine samples was 3.19 ± 1.65 ng/mL (range: 0.37˜6.02 ng/mL). The concentrations of BOLD in the victim's blood from the femoral vein and heart were 140.44 and 25.74 ng/mL, respectively. On the other hand, those in the muscular tissue from the injection site and the urine sample were 142.3 ng/g and 3474 ng/mL, respectively.

Detection of 11-nor-9-carboxy-tetrahydrocannabinol in the hair of drug abusers by LC-MS/MS analysis.

Cannabis is the second most commonly abused illicit drug after methamphetamine in South Korea. To prove cannabis consumption, 11-nor-9-carboxy-tetrahydrocannabinol (THC-COOH), the metabolite of tetrahydrocannabinol (THC), was screened for in a hair analysis. In this study, we developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis method, which was used to analyze authentic hair samples in 2017. Possible contaminants on the surface of hair samples were eliminated by washing twice each with 2mL of methanol and distilled water. After adding an internal standard (THC-COOH-d3), the hair samples (about 20mg each) were digested with 1M NaOH, extracted twice with mixed organic solvents (n-hexane:ethyl acetate), and analyzed by an LC-MS/MS system. Identification and quantification of THC-COOH and THC-COOH-d3 were performed using a multiple reaction monitoring (MRM) mode at m/z 245 and 191 and m/z 248, respectively (quantifier ions are underlined). The following validation parameters were evaluated: selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, matrix effect, and recovery. The LOD and LOQ of the method was 0.1pg/mg. Good linearity was achieved for THC-COOH in the range from 0.1 to 20pg/mg. The method showed an acceptable precision and accuracy, both of which were less than 15% at the three concentrations of THC-COOH (0.2, 1, and 10pg/mg). THC-COOH showed ion suppression at these three concentrations. The concentrations of THC-COOH in the authentic hair samples ranged from 0.10 to 27.30pg/mg (total 586 cases), and its concentrations were classified as low, medium, or high ranges, i.e., 0.10-0.39pg/mg, 0.39-1.99pg/mg, or 1.99-27.30pg/mg, respectively, according to statistical evaluation. This method showed the possibility of replacing the existing gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis. However, further development of our LC-MS/MS method is necessary in order to meet the recommended 0.05pg/mg cut-off.

Identification of trichothecene-type mycotoxins in toxic mushroom Podostroma cornu-damae and biological specimens from a fatal case by LC-QTOF/MS.

In some autopsy cases, there are unknown natural toxins that are suspected to cause serious damage to the person. However, without reference materials, it is almost impossible to identify the suspicious natural toxins by GC-MS or LC-MS. In this case, a man drank mushroom -liquor with a meal at his home. Seven hours later, he was transported to the emergency room, and 12hours later, he died. In the ingested mushroom-infused-liquor, there were pieces of mushroom that were estimated to be Podostroma cornu-damae (Hypocreaceae) based on their morphological characteristics. To identify the species, chemical component analysis was conducted using LC-QTOF-MS/MS. Monoisotopic mass, fragment ions, and isotope distributions were obtained from the LC-QTOF-MS/MS analysis. In addition, fragment ions and structure matching were tested for target compound confirmation. In this analysis, several toxic trichothecene-type mycotoxins were identified including roridin D, roridin E, roridin Q, satratoxin G, satratoxin H, satratoxin H 12'-acetate, satratoxin H 13'-acetate, satratoxin H 12',13'-diacetate, and verrucarol. At autopsy, heart blood, peripheral blood, and the stomach contents were collected, and only satratoxin H was detected in these samples. This is the first finding of a trichothecene-type mycotoxin in a human biological sample from an expected case of P. cornu-damae intoxication. We demonstrated that LC-QTOF-MS/MS analysis was an effective method for mushroom intoxication cases in the absence of reference materials. Additionally, the experience, knowledge, and analytical methods we obtained in this study will be great assets for solving other cases of possible natural toxin intoxication.

Simultaneous determination of bentazone and its metabolites in postmortem whole blood using liquid chromatography-tandem mass spectrometry.

A liquid chromatography-tandem mass spectrometry method with solid-phase extraction (SPE) was developed and validated for the detection and quantitation of bentazone and its two hydroxylated metabolites, 6-hydroxybentazone and 8-hydroxybentazone, in postmortem blood. Sample cleanup was performed using a hydrophilic-lipophilic balanced (HLB) SPE cartridge and then separated on a C18 LC column using a gradient elution of 0.1% formic acid in distilled water and 0.1% formic acid in methanol. The identification of bentazone and its hydroxylated metabolites was performed using tandem mass spectrometry with electrospray ionization in negative ion mode with selective reaction monitoring. The retention times of bentazone, 6-hydroxybentazone, 8-hydroxybentazone, and 2-methyl-4-chlorophenoxyacetic acid (MCPA, internal standard) appeared separately in the chromatogram. The matrix effect, recovery, and process efficiency of bentazone were 75.3%, 103.6% and 77.9%, respectively. In addition, good accuracy (88.2-110.5%), precision (0.5-7.5%, bias), and linearity (5-500ng/mL) were obtained with this method. The limit of detection (LOD) of bentazone, 6-hydroxybentazone, and 8-hydroxybentazone were 0.05, 0.5, and 0.5ng/mL, respectively. The method developed herein was applied to authentic samples from three fatal cases from 2016 for the determination of the corresponding bentazone and its metabolites levels. The concentration ranges of bentazone, 6-hydroxybentazone, and 8-hydroxybentazone in the heart blood from the three victims were 46.0-91.8, 4.2-6.2, and 0.2-0.6µg/mL, respectively.

Determination of AB-CHMINACA and its metabolites in human hair and their deposition in hair of abusers.

Despite global efforts to control the abuse of synthetic cannabinoids, the high-level of turnover from the market impedes regulation, endangering public health. N-[(1S)-1-(aminocarbonyl)-2-methylpropyl]-1-(cyclohexylmethyl)-1H-indazole-3-carboxamide (AB-CHMINACA) is the most popular synthetic cannabinoid in South Korea since its introduction in 2014. Nonetheless, few studies have been carried out on AB-CHMINACA and its metabolites, and its deposition in human hair. The purpose of this study was to develop and validate an analytical method for detection of AB-CHMINACA and its six metabolites in hair using a liquid chromatography tandem mass spectrometry (LC-MS/MS) system, for forensic applications. The methanol extracts of hair samples were evaporated, filtered, and analyzed by LC-MS/MS with electrospray ionization in positive ion mode. The limits of detection and quantification ranged from 0.5 to 10pg/mg and 2 to 50pg/mg, respectively. Good linearity was achieved within the range of 5-1000pg/mg or 10-1000pg/mg depending on the analyte. Intra- and inter-assay precision and accuracy values were below 15%. No significant variation was observed using different sources of hair matrices. These validation results proved the selectivity, accuracy and reproducibility of the method. The established method was applied to 37 authentic samples from suspected synthetic cannabinoid users. AB-CHMINACA and its two metabolites, AB-CHMINACA M2 and AB-CHMINACA M4, were detected. The concentration of the parent drug was much higher than those of its metabolites, and the amount of AB-CHMINACA M2 was greater than that of AB-CHMINACA M4 in all samples. No other metabolites were detected in the samples.

An LC-MS/MS method for the simultaneous determination of 15 antipsychotics and two metabolites in hair and its application to rat hair.

In recent years, the inappropriate use of antipsychotics by young Korean men has become a social problem. As military service exemptions are given for mental illness, some men pose as mental health patients to avoid military service. In order to verify the authenticity of mental illnesses, we developed simultaneous analytical methods for the detection of 15 antipsychotics and 2 of their metabolites in hair using liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The target drugs were modafinil, atomoxetine, aripiprazole, benztropine, buspirone, duloxetine, gabapentin, oxcarbazepine, topiramate, escitalopram, paliperidone, ziprasidone, lamotrigine, clonazepam, levetiracetam, and metabolites of oxcarbazepine and clonazepam. To remove possible contaminants on the hair surface, hair samples were washed twice with methanol and distilled water, and then were extracted with methanol overnight at 38°C. Desipramine-d3 was used as an internal standard. LC-MS/MS analysis was performed on an Agilent 1290 Infinity UHPLC coupled to an AB Sciex Qtrap® 5500 MS/MS. The total chromatographic run time was 14min. The following validation parameters were evaluated: selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, matrix effect, and recovery. The LOD and LOQ values for all analytes, except modafinil, ranged from 0.2 to 10pg/mg hair and from 0.2 to 20pg/mg hair, respectively. Good linearity was achieved for most of the analytes in the range of 20-200pg/mg hair. The method showed acceptable precision and accuracy, which were less than 15%, as well as satisfactory matrix effects and recoveries. Furthermore, this method was also applied to the analysis of rat hair samples. The study in rats showed that the concentrations of atomoxetine and aripiprazole in pigmented hair were significantly higher than those in non-pigmented hair. However, no significant difference was observed in the concentration of topiramate between pigmented and non-pigmented hair. This method will be useful in monitoring the inappropriate use of antipsychotics in suspects posing as mental health patients. However, further research is necessary before applying this method to authentic hair samples from mental health patients.

Determination of propofol glucuronide from hair sample by using mixed mode anion exchange cartridge and liquid chromatography tandem mass spectrometry.

The main objective of this study was to develop and validate a simpler and less time consuming analytical method for determination of propofol glucuronide from hair sample, by using mixed mode anion exchange cartridge and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The study uses propofol glucuronide, a major metabolite of propofol, as a marker for propofol abuse. The hair sample was digested in sodium hydroxide solution and loaded in mixed-mode anion cartridge for solid phase extraction. Water and ethyl acetate were used as washing solvents to remove interfering substances from the hair sample. Consequently, 2% formic acid in ethyl acetate was employed to elute propofol glucuronide from the sorbent of mixed-mode anion cartridge, and analyzed by LC-MS/MS. The method validation parameters such as selectivity, specificity, LOD, LLOQ, accuracy, precision, recovery, and matrix effect were also tested. The linearity of calibration curves showed good correlation, with correlation coefficient 0.998. The LOD and LLOQ of the propofol glucuronide were 0.2 pg/mg and 0.5 pg/mg, respectively. The intra and inter-day precision and accuracy were acceptable within 15%. The mean values of recovery and matrix effect were in the range of 91.7-98.7% and 87.5-90.3%, respectively, signifying that the sample preparation, washing and extraction procedure were efficient, and there was low significant hair matrix effect for the extraction of propofol glucuronide from hair sample on the mixed mode anion cartridge. To evaluate the suitability of method, the hair of propofol administered rat was successfully analyzed with this method.

Analysis of benzodiazepines and their metabolites using DBS cards and LC-MS/MS.

Dried Blood Spot (DBS) has been used a blood extraction method for inherited metabolic disorder screening since 1960s. With introduction of LC-MS/MS, not only DBS could be used to analysis drugs in small blood volume, but in various fields, such as toxicology, drug therapeutic monitoring, drug diagnostic screening, and illicit drugs. In toxicology field, many drugs (e.g. benzodiazepines, acetaminophen, small molecule drugs) have been tested with DBS. Compared with earlier blood extraction methods (SPE and LLE), DBS has lots of advantages; lower blood volume (less than 50µL), shorter analysis time caused by a more concise analysis procedure and lower cost. We optimized the DBS procedure and LC-MS/MS conditions for 18 benzodiazepines, seven benzodiazepine metabolites, and one z-drug (zolpidem) analysis in blood. 30µL of whole blood was spotted on FTA DMPK card C and dried for 2h in a desiccator. A 6-mm disk was punched and vortexed for 1min in a centrifuge tube with 300µL methanol/acetonitrile mixture (1:1, v/v). After evaporation, redissolved in 100µL mobile phase of LC-MS/MS and 5µL was injected. In the analysis for 26 target compounds in blood, all of the method validation parameters - LLOD, LLOQ, accuracy (intra- and inter-assay), and precision (intra- and inter-assay) - were satisfied with method validation criteria, within 15%. The results of matrix effect, recovery, and process efficiency were good. We developed a fast and reliable sample preparation method using DBS for 26 benzodiazepines, benzodiazepine metabolites, and z-drug (zolpidem).

Determination of XLR-11 and its metabolites in hair by liquid chromatography-tandem mass spectrometry.

Analysis of drugs in hair is often used as a routine method to obtain detailed information about drug ingestion. However, few studies have been conducted on disposition of synthetic cannabinoids including cyclopropylindoles (UR-144 and XLR-11) and their metabolites in hair. XLR-11 has been widely abused in South Korea recently. Identification of metabolites in hair can be an important proof of synthetic cannabinoids use because it can exclude the possibility of passive smoke exposure. In this study, we described a quantitative analytical method of XLR-11 and its metabolites (UR-144, UR-144 N-5-hydroxypentyl metabolite, UR-144 N-4-hydroxypentyl metabolite, UR-144 N-pentanoic acid metabolite and XLR-11 N-4-hydroxypentyl metabolite) in hair by liquid chromatography with ESI-MS/MS. The target analytes were extracted with methanol from washed and cut hair samples and the extracts were evaporated, filtered and analyzed by LC-MS/MS with electrospray ion source in positive-ionization mode. JWH-018-d9 and JWH-018 N-5-hydroxypentyl metabolite-d5 were used as internal standards. Chromatographic separation was completed within 15 min. No interferences were detected in 10 blank hair samples. In intra- and inter-assay precision and accuracy study, CV (%) and bias (%) were below 12. The limit of detection (LOD) was 0.1∼2 pg/mg and the limit of quantification (LOQ) was 0.2-2 pg/mg, respectively. The validation results proved that the method was selective, accurate and precise with acceptable linearity within calibration range. No significant variation was observed by different sources of matrices. This method was applied to hair samples from 14 individual suspects of XLR-11 use. In this result, XLR-11, UR-144, UR-144 N-5-hydroxypentyl metabolite and UR-144 N-pentanoic acid metabolite, XLR-11 N-4-hydroxypentyl metabolite were detected. The concentration of XLR-11 as a parent drug was much higher than other metabolites. UR-144 N-5-hydroxy metabolite and UR-144 N-pentanoic acid were detected mainly in the authentic hair samples from suspected of XLR-11 use. UR-144 N-4- hydroxypentyl metabolite was not detected in all cases.

Evaluation of postmortem redistribution phenomena for commonly encountered drugs.

We described the findings of a study into the post-mortem redistribution (PMR) of 76 drugs found in 129 drug-related cases between 2006 and 2009. Seventy six drugs (psychotropic drugs (n=14), antidepressants (n=9), sedatives (n=6) and so on) were simultaneously quantified in cardiac and peripheral blood by gas chromatography-mass spectrometry (GC/MS) or liquid chromatography-tandem mass spectrometry (LC/MS/MS). The absence, possibility or presence of PMR of drugs was determined according to the ratios of cardiac to femoral blood concentrations (C/P ratios). Proxyphylline (C/P ratio: 0.85) showed no PMR; carbamazepine was not subject to PMR; a potential for PMR of lorazepam and mirtrazapine cannot be excluded; chlordiazepoxide is subject to PMR; acetaminophen and alprazolam exhibit minimal PMR; amitriptyline and benztropine exhibit PMR. Codeine (C/P ratio: 4.9), zolpidem (C/P ratio: 3.74), chlorpromazine (C/P ratio: 2.97), fluoxetine (C/P ratio: 2.83) and propranolol (C/P ratio: 2.72) had the largest C/P ratios. Postmortem drug concentrations showed variations depending on sampling sites and characteristics of the drugs. It is continuously necessary to analyze commonly used or abused drugs in simultaneously collected cardiac and peripheral blood to establish significant reference values for PMR. These findings can be used to reach a conclusion about the cause and manner of death.

Determination and validation of tetrodotoxin in human whole blood using hydrophilic interaction liquid chromatography-tandem mass spectroscopy and its application.

A sensitive analytical method was developed for the quantitative determination of tetrodotoxin (TTX), a powerful sodium channel blocker, in human postmortem whole blood. The sample mixture was cleaned up using cation exchange SPE catridge after protein precipitation by methanol and then separated on a PC-HILIC (phosphorylcholine hydrophilic interaction liquid chromatography) column (150 mm × 2.0mm i.d., 5 µm) using a isocratic elution of 1% acetic acid and acetonitrile. The identification of TTX was performed on tandem mass spectrometry with electrospray ionization interface in positive ion mode. The retention time of voglibose (internal standard) and TTX was 5.1 and 6.0 min, respectively. TTX and internal standard (voglibose) were monitored and quantitated using the ion transitions: the respective precursor to product ion combinations, m/z 320/302 for TTX and m/z 268/92 for voglibose in the multiple reaction monitoring (MRM) mode. The recovery of TTX and voglibose was 61.4% and 62.8%, respectively and the good accuracy (97.7-103.9%), linearity (2-1200 ng/mL) and reproducibility were shown in this method. The limit of detection and limit of quantification were 0.32 ng/mL and 1.08 ng/mL, respectively. This method was applied in the case of three fishermen who were poisoned (including one death) by unknown fish on their boat in October 2010. In this case, the levels of TTX were 27.2, 30.0 and 29.7 ng/mL in heart blood, peripheral blood and serum of a victim, were 3.1 and 12.1 ng/mL in peripheral blood and 3.9 and 12.8 ng/mL in serum of two survivors, respectively.

Simultaneous analysis of Δ(9)-tetrahydrocannabinol and 11-nor-9-carboxy-tetrahydrocannabinol in hair without different sample preparation and derivatization by gas chromatography-tandem mass spectrometry.

The present study describes a gas chromatography/tandem mass spectrometry-negative ion chemical ionization assay (GC/MS/MS-NCI) for simultaneous analysis of Δ(9)-tetrahydrocannabinol (THC) and 11-nor-9-carboxy-tetrahydrocannabinol (THCCOOH) in hair. Each hair sample, of approximately 20mg, was weighed and the sample was dissolved in 1ml of 1M sodium hydroxide (30min at 85°C) in the presence of THC-d(3) and THCCOOH-d(3). For the analysis of THC, hair samples were extracted with n-hexane:ethyl acetate (9:1) two times; acetic acid and sodium acetate buffer were added for the analysis of THCCOOH, and hair samples were re-extracted with n-hexane:ethyl acetate (9:1) two times. The extracts were then derivatized with pentafluoropropionic anhydride (PFPA) and pentafluoropropanol (PFPOH). This method allowed the analysis of THC and THCCOOH using the GC/MS/MS-NCI assay. This method was also fully validated and applied to hair specimens (n=54) collected from known cannabis users whose urine test results were positive. The concentrations of THC and THCCOOH in hair ranged from 7.52 to 60.41ng/mg and from 0.10 to 11.68pg/mg, respectively. In this paper, we simultaneously measured THC and THCCOOH in human hair using GC/MS/MS-NCI without requiring different sample preparation and derivatization procedures. The analytical sensitivity for THCCOOH in hair was good, while that for THC in hair needs to be improved in further study.

Establishment of the measurement uncertainty of 11-nor-D9-tetrahydrocannabinol-9-carboxylic acid in hair.

The quantitative analysis of 11-nor-D(9)-tetrahydrocannabinol-9-carboxylic acid (THCCOOH) in hair requires a sensitive method to detect a low-pg level. Before applying the method to real hair samples, the method was validated; in this study, we examined the uncertainty obtained from around the cut-off level of THCCOOH in hair. We calculated the measurement uncertainty (MU) of THCCOOH in hair as follows: specification of the measurand, identification of parameters using "cause and effect" diagrams, quantification of the uncertainty contributions using three factors, the uncertainty of weighing the hair sample, the uncertainty from calibrators and the calibration curve, and the uncertainty of the method precision. Finally, we calculated the degrees of freedom and the expanded uncertainty (EU). The concentration of THCCOOH in the hair sample with its EU was (0.60 ± 0.1) × 10(-4)ng/mg. The relative uncertainty percent for the measurand 0.60 × 10(-4)ng was 9.13%. In this study, we also selected different concentrations of THCCOOH in real hair samples and then calculated the EU, the relative standard uncertainty (RSU) of the concentration of THCCOOH in the test sample [u(r)(c0)], the relative uncertainty percent, and the effective degree of freedom (v(eff)). When the concentrations of THCCOOH approached the cut-off level, u(r)(c0) and the relative uncertainty percent increased but absolute EU and v(eff) decreased.

Postmortem blood concentrations of organophosphorus pesticides.

Cases involving acute fatalities due to ingestion of organophosphorus pesticides (OPs), such as chlorpyrifos, diazinon, malathion and parathion, are presented. Solid-phase extraction (SPE) and gas chromatography/mass spectrometry (GC/MS) were used for the analysis of OPs in postmortem blood. After extraction with an Oasis HLB cartridge, the eluent was evaporated to dryness under a nitrogen stream at 35 degrees C, reconstituted with ethanol, and then analyzed by GC/MS. Terbufos was used as an internal standard. Verification procedures, such as the limit of detection, limit of quantification, linearity of the calibration, precision and recovery were performed. Validation data were adequate for analyzing OPs in blood. Chlorpyrifos, diazinon, malathion and parathion were detected in 31 postmortem blood samples. Parathion was the most frequently detected compound among the four pesticides. The mean concentrations of chlorpyrifos, diazinon, malathion and parathion were 0.72, 1.03, 0.82 and 2.90 mg/L, respectively.

Development of a reference material using methamphetamine abusers' hair samples for the determination of methamphetamine and amphetamine in hair.

In the present study, we developed a reference material (RM) using authentic hair samples for the determination of methamphetamine (MA) and its main metabolite, amphetamine (AP) in human hair. MA abusers' hair samples were collected, homogenized and finally bottled. The concentration of each bottle was determined using two extraction methods, agitation with 1% HCl in methanol at 38 degrees C and ultrasonication with methanol/5M HCl (20:1), followed by gas chromatography/mass spectrometry (GC-MS) after derivatization with trifluoroacetic anhydride (TFAA). Both analytical procedures were fully validated and their extraction efficiency was compared. The homogeneity of analytes was evaluated and their property values were determined with their uncertainties. The two methods were acceptable to analyze MA and AP in human hair through the validation and comparative studies using spiked and authentic hair samples as well as NIST SRM 2379 certified reference material. Satisfying homogeneity was reached for MA and AP in the prepared RM. Finally, a human hair RM containing MA and AP is prepared at the level of 7.64+/-1.24 and 0.54+/-0.07 ng/mg, respectively. This material can be useful in forensic laboratories for internal quality control and external quality assurance.