Hiromi Arimoto

Ferroceneboronic acid as a derivatization reagent for the determination of brassinosteroids by high-performance liquid chromatography with electrochemical detection.

Abstract A micro-scale method for the determination of brassinosteroids as ferroceneboronates by high-performance liquid chromatography with electrochemical detection has been developed. Ferroceneboronic acid (FBA) proved to be satisfactory for use in the derivatization of brassinosteroids with respect to reactivity and sensitivity. The steroids were readily condensed with FBA under mild conditions to provide the corresponding boronates, exhibiting maximum sensitivity at + 0.6 V vs. a silver-silver chloride reference electrode with a detection limit of 25 pg for brassinolide. The method was successfully applied to the determination of natural brassinosteroids in a plant. Brassinolide, dolichosterone, norcastasterone and castasterone were identified in the pollen of sunflower ( Helianthus annuus L.).

Determination of sultopride and tiapride in serum by gas chromatography using a surface ionisation detector

A sensitive and selective method has been developed for the determination of sultopride and tiapride in serum using gas chromatography with a surface ionisation detector. No interfering peaks from endogenous substances were observed. The method showed good reproducibility and accuracy, and the standard curve was linear up to 2 micrograms/ml with a correlation coefficient of 0.999. This method is applicable to pharmacokinetic studies and therapeutic drug monitoring of sultopride and tiapride.

Selective determination of haloperidol in human serum : surface ionization mass spectrometry and gas chromatography with surface ionization detection

Surface ionization organic mass spectrometry (SIOMS) has been performed on the clinically important drug haloperidol using quadrupole mass spectrometry in which the thermal ion source has a rhenium oxide emitter. The surface ionization (SI) mass spectrum is presented, interpreted in a purely empirical way by means of evidence from previous investigations, and then compared to results from conventional electron impact (EI) ionization. An approach to detection of this drug in serum by gas chromatography (GC) with a surface ionization detector (SID) and GC-SIOMS is described. This approach demonstrates that (a) haloperidol is efficiently surface-ionized, giving a unique SI mass spectrum, (b) experimental results rationalize the combined sensitivity and selectivity of the GC-SID for the examined drug, (c) the detection limit for haloperidol in serum is 1.1 ng/ml (S/N = 3) by GC-SID (the coefficients of variation of the assay are generally low, i.e., below 8.5%) and (d) the GC-SIOMS coupling can be used for sensitive and selective detection of haloperidol in serum.

High-performance emitters for use in a surface ionization detector for gas chromatography

Abstract An attempt has been made to find good emitter materials for use in a surface ionization detector for gas chromatography. The sensitivity, detectability and stability characteristics were examined for ten refractory metals such as Pt, Ir and Re using tri- n -butylamine as a test compound. Of these materials, iridium is the best in terms of detectability. It not only provides six times the detection ability of Pt, but also shows good stability, reproducibility and durability.

Some application of the surface ionisation detector in gas chromatography

The application of the surface ionisation detector to gas chromatography is illustrated using six examples of the analysis of formulations: (1) a butylamine mixture, (2) a polyaromatic hydrocarbon mixture, (3) a terpene mixture, (4) a steroid mixture, (5) a drug mixture and (6) the determination of lidocaine in serum. Advantageous sensitivity (better detection limit), substance specificity and applicability are reported.

Rapid and sensitive determination of aprindine in serum by gas chromatography using a surface ionization detector

A rapid and highly sensitive method for the determination in serum of aprindine, an antiarrhythmic drug, was developed employing gas chromatography with a surface ionization detector. No interfering peak from endogenous substances appeared when an organic phase was directly injected into the system after single extraction from a serum sample. A standard curve obtained was linear up to the serum level of 6 micrograms/ml, and the limit of sensitivity was 16 pg. The method described is applicable to routine therapeutic monitoring of serum concentrations of aprindine.