Toshiyuki Mitsui

Use of a piezoelectric quartz crystal as a conductivity detector and its analytical application.

オシレーターから水晶発振子への回路を開き,その部分(電極)を液体に浸しても,水晶発振子は安定に発振し,その際の基本振動数は,電解質溶液に浸した場合には電気伝導度に,又,有機溶媒に浸したときには主に誘電率に依存して変化する.線状電極を電解質溶液に浸した場合には,電気伝導度に比例して振動数が変化し,更に電極間隔が狭くなるほど感度が増加した.従って,この水晶発振子は溶液の電気伝導度や誘電率の検出器として用いることができるので,液体クロマトグラフの電気伝導度検出器として,又,容量分析の終点検出器としての利用を試みた.

Forensic investigation of counterfeit coins

Counterfeit coins were investigated using X-ray fluorescence (XRF) for a quantitative analysis without any pretreatment and by a metallic microscope for observation of their microstructures. Copper, nickel, iron, zinc, manganese, chromium, cobalt and lead were detected by XRF. Cluster analysis was applied to classify the counterfeit coins using their major six elements (Cu, Ni, Fe, Zn, Mn and Cr). The analytical results showed that the eighty-nine counterfeit coins could be divided into three groups, which were dependent upon the content of iron, chromium and zinc. Many bent micro-structures were observed at the letter and figure position and at the edge using a metal microscope after chemical etching.

Classification of counterfeit coins using multivariate analysis with X-ray diffraction and X-ray fluorescence methods

Counterfeit coins (277 samples) were analyzed by both X-ray diffraction (XRD) and X-ray fluorescence (XRF) methods without any pretreatment. The counterfeit coins were clearly classified into two groups using cluster analysis (CA) and principal component analysis (PCA) for XRD peak patterns. One group (250 samples) was made by a pressed method and another one (27 samples) was made by a nickel-plated method. Using four elements (Cu, Ni, Fe and Zn) and obtaining XRF for 257 samples, they could be divided into four groups by CA. On the other hand, they were classified into five groups using their diameter, thickness, weight, density, density/thickness and density/weight. The latter classification method would suggest something of a change in the process of the pressed method.

Classification of hashish by pyrolysis - gas chromatography

Abstract The classification of hashish was studied by pyrolysis-gas chromatography. To estimate the route through which they had been obtained by suspects, detailed classification of samples of hashish was performed using cluster analysis after normalization of the peaks in the pyrograms against the highest peak in each pyrogram. The results of cluster analysis were presented as a dendrogram, an easily interpreted visual representation of the similarity among samples. The 13 different samples collected were roughly divided into two groups. The observed datum for an unknown sample was evaluated by comparison with the known samples and classified into one of the groups. The dendrogram proved to be effective in discriminating between hashish obtained from different sources.

Analysis of benzphetamine and its metabolites in rat urine by liquid chromatography-electrospray ionization mass spectrometry.

An analytical method to identify and determine benzphetamine (BMA) and its five metabolites in urine was developed by liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) using the solid-phase extraction column Bond Elut SCX. Deuterium-labeled compounds, used as internal standards, were separated chromatographically from each corresponding unlabeled compound in the alkaline mobile phase with an alkaline-resistant ODS column. This method was applied to the identification and determination of BMA and its metabolites in rat urine collected after oral administration of BMA. Under the selected ion monitoring mode, the limit of quantitation (signal-to-noise ratio 10) for BMA, N-benzylamphetamine (BAM), p-hydroxybenzphetamine (p-HBMA), p-hydroxy-N-benzylamphetamine (p-HBAM), methamphetamine (MA) and amphetamine (AM) was 700 pg, 300 pg, 500 pg, 1.4 ng, 6 ng and 10 ng in 1 ml of urine, respectively. This analytical method for p-HBMA, structurally closer to the unchanged drug of all the metabolites, was very sensitive, making this a viable metabolite for discriminating the ingestion of BMA longer than the parent drug or other metabolites in rat.

Determination of the total amount of morphine alkaloids in opium by pyrolysis-gas chromatography using principal component analysis

Abstract The total amount of morphine alkaloids in opium was determined by pyrolysis-gas chromatography (Py-GC) using principal component analysis. The sample suspended in ethanol was added to a pyrolysis foil (590 °C) in the presence of an iron and potassium chloride mixture. The twelve peaks obtained by Py-GC were used for quantitative principal component analysis. The total amount of morphine alkaloids in opium was calculated to substitute the principal component score and factor contribution for the peak area. The total content of morphine alkaloids in opium was found to range from 57.4 to 67.2%.

Curie-point pyrolysis-gas chromatography of aliphatic amines in the presence of metal powder and inorganic salt

Abstract A fundamental investigation has been undertaken to determine the optimum conditions for the addition of metal powder and metal chloride to a pyrolysis foil for the analysis of aliphatic amines by means of Curie-point pyrolysis-gas chromatography. It is suggested that the effectiveness of the addition of a suitable inorganic salt to the pyrolysis foil is associated with the ability of the metal ion to complex with amines. Nickel powder was useful when the pyrolysis was carried out at lower temperatures and chromium was preferred at higher temperatures. The suitable pyrolysis temperature was related to the molecular weight of the amine samples. The optimum conditions for the pyrolysis of three butylamines resembled one another. The recommended conditions for dibutylamine hydrochloride are that the pyrolysis be carried out at 333°C in the presence of a mixture of nickel powder and cobaltous chloride hexahydrate (10:3 w/w). The calibration curves for dibutylamine hydrochloride, constructed by using the peak area method, were linear over the sample size range of 2.1–41.2 μg. The relative standard deviation (n = 4) was 2.56% for 20.6 μg.

Determination of alkaloidal narcotics by pyrolysis-gas chromatography

Abstract The alkaloidal narcotics in urine are extracted with dichloromethane and heated to evaporate the solvent. The salts of alkaloidal narcotics are pyrolyzed and analyzed by gas chromatography. By this method, the alkaloidal narcotics can be determined with high sensitivity and with good reproducibility.

Classification of prepaid cards based on multivariate treatment of data obtained by X-ray fluorescence analysis.

Two hundred prepaid cards, which had been used in Nagoya-citys subway in Japan, and another 32 prepaid cards (11 were real turnpike cards, 20 were counterfeit cards and 1 was a white card) were evaluated by X-ray fluorescence (XRF) without any pre-treatment. A preliminary investigation was performed on 200 prepaid cards in order to find an identification method for the turnpike cards. By plotting the relative intensity of titanium versus that of iron obtained by XRF, the cards were clearly classified into seven groups. On the other hand, the cards could be divided into four groups by a multivariate analysis using the relative intensities of five elements such as chlorine, calcium or tin, titanium, iron and barium. Using these results to classify the Japanese turnpike cards, they were divided into three groups or two groups. One of three groups or two groups was the counterfeit card group.

Effect of adding metal powder and inorganic salt to a pyrolysis foil on selective pyrolysis of phenyl alkylamines by curie-point pyrolysis−gas chromatography

Abstract The purpose of this study was to determine the effects on pyrolysis of metal powder and inorganic salt additives. Aniline, benzylamine, 2-phenyl-1-ethylamine and 3-phenyl-1-propylamine were used as samples for pyrolysis, because they have a benzene ring and an amino group as common structural units, and alkyl side chains of varying length. It can be concluded that the choice of metal and inorganic salt additives is one of the most important factors in the design of procedures allowing a high degree of control over the products of pyrolysis. It is suggested that the choice of metal should be made on the basis of bond dissociation energy, and the choice of salt on the basis of cation complexation ability with amine.