Determination of diborane in the air of workplace by ICP-AES / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>A sampling method was established to collect diborane in the air of workplace and an ICP-AES method was developed to determine the Boron in desorbed solution.</p><p><b>METHOD</b>Diborane in the air of workplace was collected by solid sorbent tube filled with oxidant impregnated activated carbon. The adsorbed diborane was desorbed into 3% H2O2 aqueous, and then the desorbed Boron was determined by ICP-AES.</p><p><b>RESULTS</b>The sampling efficiency of this method was 99.6% with the desorption efficiency of diborane with 5.660 microg and 56.6 microg spiked were 90.9% and 99.5%, respectively. Both the intra-and inter-precision RSD were less than 8%. The standard curve of this method ranged from 0.1 to 10.0 microg/ml (Boron), and the LOD and LOQ were 0.011 mg/m3 and 0.035 mg/m3 (15L samples) respectively.</p><p><b>CONCLUSION</b>The method established was suitable for diborane sampling and determination in the air of workplace.</p>

Analysis of paraquat in blood and urine by sodium borohydride/nickel chloride chemical reduction-gas chromatography/thermionic specific detector / 法医学杂志

OBJECTIVE@#To establish a new method for the analysis of paraquat in blood and urine by sodium borohydride/nickel chloride chemical reduction-gas chromatography/thermionic specific detector.@*METHODS@#An initial procedure of precipitation was performed by adding hydrochloric solution with sodium chloride and a mixture of chloroform and ethanol. Then the analyte contained in supernatant was reduced by a reduction system of sodium borohydride and nickel chloride and extracted by acetic ether. Ethyl paraquat (EPQ) was used as internal standard. GC/TSD was used to identify and quantify the analyte.@*RESULTS@#The limits of detection (S/N=3) in blood and urine were 0.002 and 0.004 microg/mL, respectively. The linear ranges were 0.050-30.0 microg/mL. Correlation coefficients in blood and urine were 0.999 and 0.998, respectively. The recoveries exceeded 80% both in blood and urine.@*CONCLUSION@#This method is applicable for quantification of paraquat in biological fluids.

Histopathological changes of testes and eyes by neutron irradiation with boron compounds in mice

This study was performed to investigate the biological effects of boron neutron capture therapy (BNCT) on the testes and eyes in mice using HANARO Nuclear Reactor, Korea Atomic Energy Research Institute. BNCT relies on the high capacity of (10)B in capturing thermal neutrons. Sodium borocaptate (BSH, 75 ppm, iv) and boronophenylalanine (BPA, 750 ppm, ip) have been used as the boron delivery agents. Mice were irradiated with neutron (flux: 1.036739E +09, Fluence 9.600200E+12) by lying flat pose for 30 (10 Gy) or 100 min (33 Gy) with or without boron carrier treatment. In 45 days of irradiation, histopathological changes of the testes and eyes were examined. Thirty-three Gy neutron irradiation for 100 min induced testicular atrophy in which some of seminiferous tubules showed complete depletion of spermatogenic germ cells. Lens epithelial cells and lens fiber were swollen and showed granular changes in an exposure time dependent manner. However, boron carrier treatment had no significant effect on the lesions. These results suggest that the examination of histopathological changes of lens and testis can be used as "biological dosimeters" for gauging radiation responses and the HANARO Nuclear Reactor has sufficient capacities for the BNCT.

Preparation of testosterone using microbial metabolite of cholesterol

Natural sterols are potential raw materials for the prepartion of pharmacologically active steroid products. This paper details preparation of testosterone, one of the steroidal hormones, through microbial metabolism of cholesterol followed by chemical reduction. The side chain of cholesterol was selectively cleaved by Mycobacterium smegmatis PTCC 1307, and then selective reduction of resulting 17-keton group of androst-4-ene-3, 17-dione [AD], the main product of microbial transformation, with sodium borohydride at -10°C gave testosterone in high yeild [90%]. Assignment of structures were made by IR, NMR, Mass, and UV spectroscopic data

Derivados de prostaglandinas partiendo de la prostaglandina A2: I. Estudio de la reacción de reducción del 15-acetato PGA2 metil ester / Prostaglandin derivatives from prostaglandin A2: I. Study of the reaction of the 15 acetate PGA2 methyl ester

Se efectúa el estudio de la reacción de reducción del 15-acetato PGA2 metil éster con borohidruro de sodio, el cual provoca la pérdida del doble enlace C10-C11 al seguir un mecanismo de adición 1,4 de acuerdo con nuestras condiciones de trabajo y se demuestra que es un reactivo no estereoespecífico. Esto se comprueba mediante el análisis espectroscópico IR y UV, así como por cromatografía de capa delgada de los productos obtenidos y verificados por el posterior producto de oxidación

Reduction of parochial ketones with optically active borohydride reagents

The phenomenon of asymmetric induction in the synthesis of compounds that already contain one or more asymmetric carbon atoms has been recognized for many years, the classic work in a cyclic system being that of McKenzie. Many types of asymmetric synthesis have been reported in which prochiral ketones have been reduced to optically active alcohols utilizing optically active reducing agents. Many studies mostly based on the use of lithium aluminium hydride [LAH] modified by chiral alcohols, amino alcohols and amines have been conducted altering both the reagents and the experimental conditions to obtain an optimum fit and to gain an insight into the mechanism of reduction. On the other hand, a few studies on the use of sodium borohydride [NaBH4] in the same type of asymmetric reduction have been reported. In the last few years, growing attention has been devoted to asymmetric synthesis under phase transfer condition. Recently, interesting results have been obtained by Sugimoto et al. in the asymmetric reduction of aromatic ketones with NaBH[4] in the presence of bovine serum albumin in alkaline solution. Accordingly, we were interested in the present investigations to study the asymmetric reduction of ketones with chirally modified reagents prepared from NaBH[4] and optically active acids