Yasumasa Iwasaki

Detection of amphetamines in urine using head space-solid phase microextraction and chemical ionization selected ion monitoring☆

An accurate, simple and rapid method for qualitative and quantitative analysis of amphetamine and methamphetamine in urine was developed using head space-solid phase microextraction and gas chromatography-mass spectrometry/chemical ionization selected iron monitoring. A vial containing a urine sample potassium carbonate and pentadeuterated methamphetamine which was used as an internal standard was heated at 80 degrees C for 20 min. The needle of a solid phase microextraction device was passed through the septum, and the extraction fiber in the needle was exposed for 5 min in the head space of the vial. The needle was removed from the vial and inserted into the injection port of gas chromatograph or gas chromatograph/mass spectrometer. The compounds adsorbed on the fiber were detached by exposing the fiber in the injection port, and analyzed. The proposed method was more than 20 times more sensitive than the conventional head space method.

Rapid analysis of amphetamines in blood using head space-solid phase microextraction and selected ion monitoring

A simple and rapid method for analysis of methamphetamine (MA) and amphetamine (AP) in blood was developed using head space-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry/electron impact ionization-selected ion monitoring (GC-MS/EI-SIM). A vial containing a blood sample, sodium hydroxide, and pentadeuterated methamphetamine as an internal standard, was heated at 80 degrees C for 20 min. The extraction fiber of the SPME was exposed for 5 min in the head space of the vial. First, heptafluorobutyric anhydride solution was injected into the injection port of the GC-MS to make heptafluorobutyramide (HFB) derivatives of amphetamines, and compounds absorbed on the fiber were detached by exposing the fiber in the injection port. Straight calibration curves of MA and AP were obtained from 0.01 to 2 micrograms/g in blood, respectively. No interfering substances were found, and the time for analysis was 30 min for one sample.

Simple analysis of local anaesthetics in human blood using headspace solid-phase microextraction and gas chromatography–mass spectrometry–electron impact ionization selected ion monitoring

A simple method for analysis of five local anaesthetics in blood was developed using headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry-electron impact ionization selected ion monitoring (GC-MS-EI-SIM). Deuterated lidocaine (d10-lidocaine) was synthesized and used as a desirable internal standard (I.S.). A vial containing a blood sample, 5 M sodium hydroxide and d10-lidocaine (I.S.) was heated at 120 degrees C. The extraction fiber of the SPME system was exposed for 45 min in the headspace of the vial. The compounds adsorbed on the fiber were desorbed by exposing the fiber in the injection port of a GC-MS system. The calibration curves showed linearity in the range of 0.1-20 microg/g for lidocaine and mepivacaine, 0.5-20 microg/g for bupivacaine and 1-20 microg/g for prilocaine in blood. No interfering substances were found, and the time for analysis was 65 min for one sample. In addition, this proposed method was applied to a medico-legal case where the cause of death was suspected to be acute local anaesthetics poisoning. Mepivacaine was detected in the left and right heart blood samples of the victim at concentrations of 18.6 and 15.8 microg/g, respectively.

Site dependence of methamphetamine concentrations in blood samples collected from cadavers of people who had been methamphetamine abusers

Various blood samples were collected from heart cavities and blood vessels in eight autopsy cases of people who had been methamphetamine abusers. Methamphetamine and its metabolite, amphetamine, were determined by gas chromatography-mass spectrometry-selected ion monitoring. In four cases where left and right heart blood samples were collected, methamphetamine concentrations in the left heart blood samples were 1.9–2.6 times higher than those in the right heart blood samples. In three cases where pulmonary vein blood samples were collected, methamphetamine concentrations in the pulmonary vein blood samples were higher than those in other blood samples sites. To interpret the blood methamphetamine concentrations, site dependence should be taken into consideration.

Tracheal intubation of a difficult airway using Airway Scope, Airtraq, and Macintosh laryngoscope: a comparative manikin study of inexperienced personnel.

BACKGROUND:The Airway Scope (AWS) (Pentax-AWS®, Hoya Corp., Tokyo, Japan) and the Airtraq® (ATQ) (Prodol, Vizcaya, Spain) have similarities in the novel structures of their blades. In this study, we evaluated the ease of use of the AWS and ATQ compared with the Macintosh laryngoscope (ML) by inexperienced personnel in a simulated manikin difficult airway. METHODS:Twenty-four fifth-year medical students with no previous experience in tracheal intubation participated in this study. We used an advanced patient simulator (SimMan®, Laerdal Medical, Stavanger, Norway) to simulate difficult airway scenarios including cervical spine rigidity, limited mouth opening, and pharyngeal obstruction. The sequences in selecting devices and scenarios were randomized. Success rates for tracheal intubation, and the time required for visualization of the glottis, tracheal intubation, and inflation of the lungs, and the number of optimization maneuvers and dental click sounds were analyzed. The 3 different intubation devices were tested in 4 different scenarios by 24 students. RESULTS:Both the AWS and ATQ had very high success rates of tracheal intubation compared with the ML (AWS 100%*; ATQ 98%*; and ML 89%; *P < 0.05 AWS, ATQ versus ML). The time to intubation with the AWS was significantly shorter than with the ATQ and ML (AWS 11 ± 6 seconds; ATQ 16 ± 12 seconds; and ML 16 ± 11 seconds; *P < 0.05 AWS versus ATQ, ML). The number of optimization maneuvers with the AWS was significantly lower than with the ATQ and ML. There were significantly more audible dental click sounds with the ML than with the AWS and ATQ. CONCLUSION:Both the AWS and ATQ may be suitable devices for difficult intubation by inexperienced personnel in this manikin simulated scenario. Further studies in a clinical setting are necessary to confirm these findings.

Simple analysis of arylamide herbicides in serum using headspace-solid phase microextraction and GC/MS

Abstract A simple and sensitive method for analysis of four arylamide herbicides (butachlor, propanil, diphenamide and propyzamide) in serum was developed using a headspace–solid phase microextraction (SPME) and a gas chromatograph–mass spectrometer (GC–MS). A vial containing a serum sample and sodium chloride was heated at 90°C. The extraction fiber of the SPME was exposed for 45 min in the headspace of the vial. The compounds adsorbed on the fiber were desorbed by exposing the fiber in the injection port of the GC–MS. The calibration curves, using an internal standard method, demonstrated good linearity throughout the concentration range from 0.25 to 10.0 μg/ml. Propyzamide was used for an internal standard. The limit of detection was 0.10, 0.05, and 0.25 μg/ml for butachlor, diphenamide, and propanil, respectively. No interferences were found, and the time for analysis was 60 min for one sample. In addition, this proposed method was applied to a suicide case in which the patient ingested Kusanon A ® , a herbicide. Propanil, which was the main ingredient in the herbicide, was detected in the eight serum samples collected from the patient during the hospitalization at the concentration range from 26.7 to 1.1 μg/ml.

On the influence of postmortem alcohol diffusion from the stomach contents to the heart blood

Alcohol concentrations in the mixed left and right heart blood, urine and stomach contents of 186 cadavers were analyzed by gas chromatography in order to find the influence of postmortem diffusion of alcohol from the stomach contents to the heart blood. In 39 cases where blood alcohol concentrations (BACs) were less than 0.10 mg/g, alcohol in the stomach contents was suggested to be due to postmortem production, and the postmortem diffusion of alcohol from the stomach contents to the heart blood was less than 10%. In 147 where BACs were 0.10 mg/g and more, ratios of BAC to urine alcohol concentration (UAC) were 1.0 and more in 47 cases (32%), and less than 1.0 in 100 cases (68%). In 17 of these 147 cases, alcohol concentrations in stomach contents (SACs) were more than ten times as high as BACs. Where the highest ratio of SAC/BAC was 60.1, the BAC of 0.14 mg/g was suspected to be due to drinking. In the case where the highest SAC was 50.8 mg/g, the BAC of 5.18 mg/g, the highest in this study, seemed to be little affected by the diffusion. These results suggest that it is important to compare BAC, UAC and SAC to assess the influence of postmortem diffusion of alcohol from the stomach contents to the heart blood.

Automated procedure for determination of barbiturates in serum using the combined system of PrepStation and gas chromatography-mass spectrometry.

A system of an automatic sample preparation procedure followed by on-line injection of the sample extract into a gas chromatograph-mass spectrometer (GC-MS) was developed for the simultaneous analysis of seven barbiturates in human serum. A sample clean-up was performed by a solid-phase extraction (SPE) on a C18 disposable cartridge. A SPE cartridge was preconditioned with methanol and 0.1 M phosphate buffer. After loading 1.5 ml of a diluted serum sample into the SPE cartridge, the cartridge was washed with 2.5 ml of methanol-water (1:9, v/v). Barbiturates were eluted with 1.0 ml of chloroform-isopropanol (3:1, v/v) from the cartridge. The eluate (1 microl) was injected into the GC-MS. The calibration curves, using an internal standard method, demonstrated a good linearity throughout the concentration range from 0.1 to 10 microg ml(-1) for all barbiturates extracted. The proposed method was applied to 27 clinical serum samples from three patients who were administrated secobarbital.

Automated preparation and analysis of barbiturates in human urine using the combined system of PrepStation and gas chromatography-mass spectrometry

A system for an automatic sample preparation procedure followed by on-line injection of the sample extract into a gas chromatography-mass spectrometry (GC-MS) system was developed for the simultaneous analysis of seven barbiturates in human urine. Sample clean-up was performed by a solid-phase extraction (SPE) on a C18 disposable cartridge. A SPE cartridge was preconditioned with methanol and 0.1 M phosphate buffer. After loading a 1.5 ml volume of a urine sample into the SPE cartridge, the cartridge was washed with 2.5 ml of methanol-water (1:9, v/v). Barbiturates were eluted with 1.0 ml of chloroform-isopropanol (3:1, v/v) from the cartridge. The eluate (1 microl) was injected into a GC-MS system. The calibration curves, using an internal standard method, demonstrated a good linearity throughout the concentration range from 0.02 to 10 microg/ml for all barbiturates extracted. The proposed method was applied to several clinical cases. The total analysis time for 20 samples was approximately 14 h.

Clinical and toxicological findings of acute intoxication with synthetic cannabinoids and cathinones

Reporting of the analytical and clinical findings of synthetic cannabinoids and cathinones is essential in carrying out a complete clinical assessment of new psychoactive substances.