Mayumi Nishikawa

Determination of Methamphetamine and Its Related Compounds Using Fourier Transform Raman Spectroscopy

Fourier transform Raman spectroscopy (FT-Raman) is investigated as a simple and rapid method for the determination of the abused drug methamphetamine and its related compounds. Compounds can be reliably identified by using measurements made nondestructively and without the need for any sample preparation in around 1 min. The Raman spectrum of methamphetamine hydrochloride (MA) shows clear differences in spectra from a range of its related compounds such as amphetamine sulfate and ephedrine hydrochloride. These differences are adequate for spectral differentiation of the compounds. With the use of the FT-Raman technique, MA is also reliably identifiable to a detection limit of 1% (w/w) diluted in sodium chloride or water. FT-Raman spectra of MA were recorded through plastic packaging (polyethylene or polypropylene bags) typical of that used either by criminals for transportation or by law enforcement for containing and sealing evidence. Measurements could be made directly without removing the drug from the bag; excellent-quality spectra could be obtained with very little perturbation by the plastic bag.

The analysis of cocaine and its metabolites by liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (LC/APCI-MS)

The method for simultaneous determination of cocaine and its four metabolites (benzoylecgonine, ecgonine methyl ester, ecgonine and norcocaine) in urine by liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (LC/APCI-MS) was studied. The mass spectra showed the quasi-molecular ions, [M+H]+ as the base peak. LC/APCI-MS analysis was performed by focusing the characteristic ions at m/ = 186, 290, 200, 304 and 290 for ecgonine, benzoylecgonine, ecgonine methyl ester, cocaine and norcocaine, respectively. Cocaine and its four metabolites were well separated by high performance liquid chromatography (HPLC). The recoveries of cocaine and its metabolites from the spiked urine were 40.3-94.7% by solid-phase extraction with two type cartridges (Bond Elut Certify and Bond Elut SCX).

Determination of the main hydrolysis product of O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate, ethyl methylphosphonic acid, in human serum

For the unequivocal proof of the use of a nerve agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX), a rapid, accurate and sensitive method which allows us to identify its main hydrolysis product ethyl methylphosphonic acid (EMPA) in human serum was explored by GC-MS. GC-MS analysis was performed after solvent extraction with acetonitrile in acidic conditions from the serum sample, which was previously deproteinized by micro-ultrafiltration, and subsequent tert.-butyldimethylsilyl derivatization with N-methyl-N-(tert.-butyldimethylsilyl)trifluoroacetamide (MTBSTFA) with 1% tert.-butyldimethylsilyl chloride (t-BDMSC). Linear calibration curves were obtained in the concentration range from 50 to 500 ng/ml for EMPA in the full-scan EI mode and from 5 to 50 ng/ml for EMPA in the SIM EI mode. The relative standard deviation obtained at a sample concentration of 50 ng/ml was 8.4% in the full-scan mode and 7.3% in the SIM mode. Upon applying the full-scan EI and CI mode, 40 ng/ml and 80 ng/ml were the detection limits. Using the SIM-EI mode, in which the ion at m/z 153 was chosen, the limit was 3 ng/ml.

Determination of the main hydrolysis products of organophosphorus nerve agents, methylphosphonic acids, in human serum by indirect photometric detection ion chromatography

For the verification of the use of chemical warfare agents (CWA), sarin, soman and VX, a simple rapid and accurate method which allows us to simultaneously determine their degradation products, isopropyl methylphosphonic acid (IPMPA), pinacolyl methylphosphonic acid (PMPA), ethyl methylphosphonic acid (EMPA) and methylphosphonic acid (MPA), in human serum, was explored by indirect photometric detection ion chromatography (IPD-IC) which employs an anion-exchange column. IC analysis was performed after sample preparation with an Ag+-form cation-exchange resin cartridge, and the four methylphosphonic acids could be separated well. The proposed conditions are as follows: eluent, 0.5 mM phthalic acid-0.1 mM Tris (hydroxymethyl) aminomethane-5% acetonitrile; flow-rate, 1.0 ml/min; temperature, 50 degrees C; UV detector, 266 nm. All four methylphosphonic acids were eluted within 30 min with hardly any disturbance by impurities in the serum. Linear calibration curves were obtained for MPA, EMPA and IPMPA in the concentration range from 50 ng/ml to 1 microg/ml and for PMPA from 100 ng/ml to 1 microg/ml. The relative standard deviation for the methylphosphonic acids ranged from 3.8 to 6.9% at 500 ng/ml and the detection limits were 40 ng/ml for MPA, EMPA and IPMPA and 80 ng/ml for PMPA. The method would be suitable for analysis of human serum samples.

Direct detection of serum psilocin glucuronide by LC/MS and LC/MS/MS: time-courses of total and free (unconjugated) psilocin concentrations in serum specimens of a “magic mushroom” user

Psilocin glucuronide (PCG) was directly identified in serum specimens of a “magic mushroom” user by liquid chromatography/mass spectrometry (LC/MS) and LC/MS/MS, together with the free (unconjugated) psilocin (PC). A major part of serum PC existed in the conjugated form. To quantify the total (conjugated plus free) PC in serum, enzymatic hydrolysis conditions were optimized using the user’s urine as the source of PCG; PCG in serum could be completely hydrolyzed by Escherichia coli β-glucuronidase. Using the established procedure, both total and free PC in the serum specimens of the user collected at various intervals were quantified. For the first specimen collected 5h after magic mushroom ingestion, 71.0 ng/ml of total PC and 13.3 ng/ml of free PC were detected. The ratio of free PC to total PC decreased with time after ingestion. The β-glucuronidase treatment of serum was found to clearly extend the detectable period of the serum PC; PC could be detected even 52 h after ingestion of magic mushroom.

Applications of Lc/Ms in Forensic Chemistry

AbstractVarious analytical techniques for highly sensitive liquid chromatography / mass spectrometry (LCIMS) and their applications in forensic chemistry have been investigated The following three types of LCMS instruments were used for this study 1) a Micromass model PLATFORM II equipped with an atmospheric pressure chemical ionization (APCI) or an electrospray ionization (ESI) interface, 2) a Shimadzu model QP-1100EX combined with a thermospray TSP interface; 3) a JEOL model JMS-SX102A fitted with a Frit-fast atom bombardment ionization (Frit-FAB) interface Optimization of capillary voltage and the flon rate of the inobile phase were found for ESI-LCfilS The relationship between the composition of mobile phase and ionization efficiency was investigated in the ESI, APCI and TSP types of LC/MS In ESI-LC/MS analysis. the use of a semi-micro column (15 mm 1D) allowed about ten times more sensitive an analysis than a conventional column (46 mm ID)In order to examine the provable period of triazolam, which is...

Screening Test of stimulants in human urine utilizing headspace gas chromatography for field test

An accurate and simple screening method of stimulants in human urine using headspace gas chromatography utilizing heat of dissolution of potassium carbonate was developed. A 4.9-g portion of potassium carbonate was put into the vial prior to sending to the field, and a 5-ml aliquot of urine, suspected of containing stimulants and internal standard components was pipetted. After the vial was sealed and shaken by hand, 1 ml of its headspace gas was taken by disposable syringe and injected into the gas chromatograph. A compact gas chromatograph device with flame ionization detector and fused silica capillary column was developed for this experiment. Detection limits of methamphetamine and amphetamine were 1.0 micrograms/ml and 1.5 micrograms/ml, respectively.

Analysis of methylbenactyzium bromide in human urine by thin-layer chromatography and pyrolysis gas chromatography

A rapid and simple method of utilizing thin-layer chromatography (TLC) and pyrolysis gas chromatography (PyGC) for the identification and determination of methylbenactyzium bromide in human urine was studied in this report. Methylbenactyzium bromide was extracted from urine with ODS-cartridge (Sep-Pak C18), then spotted onto a silica gel 60 F254 TLC plate. After development, the separated spot of methylbenactyzium bromide was scraped and wrapped with a ferromagnetic foil without extraction by any organic solvents. The sample was applied into PyGC analysis. The optimum temperature for pyrolysis was 590 degrees C. The main degradation product of methylbenactyzium bromide was identified as diphenylmethane in this procedure by gas chromatography/mass spectrometry (GC/MS). A calibration graph prepared by absolute calibration method showed a good linearity over the concentration range of 1-75 micrograms/spot for methylbenactyzium bromide. The coefficient of variation obtained for eleven replicate analyses of the 3 micrograms/spot of standard methylbenactyzium bromide was 3.8%. The detection limit of this compound by this procedure was 0.1 micrograms/spot.