Objective To establish a method for determination of trace bromate in flour and the products by ion chromatography.Methods Conductance-ion chromatography and Ionpac~R AS9-HC column were employed and 9.0 mmol/L sodium carbonate was used as the eluent,the flow rate was 1.0 ml/min.BrO_3~-in the samples soaked in the purified water was extracted by ultrasonic microwave,the water-soluble macromolecules were removed by ultra filtration cup in the extract,then the direct injection determination was conducted.Results The lowest detection limit was 0.01 mg/L,the quantitative detection limit was 0.03 mg/kg,the relative standard deviation was 0.6%-7.6%,the recovery rate was 97.8%-103.6%.Conclusion This method is simple,rapid,accurate,sensitive and is applicable to the determination of trace bromate in flour and the products.

AIMTo study the microbial transformation of sinenxan A.

METHODSChoose two strains of Fungi (Mucor spinosus AS 3.3450 and Cunninghamella echinulata AS 3.3400) and a strain of bacterium (Proteus vulgaris AS 1.1208) to transform the substrate.

RESULTSThree products were obtained and identified as 10-deacetylsinenxan A1, 6 alpha-hydroxy-10-deacetylsinenxan A2 and 9 alpha-hydroxy-10-deacetylsinenxan A3 respectively.

CONCLUSIONSinenxan A is facile to be transformed by microorganisms, the 10-acetyl group of which is an active group.

Acetates ; isolation & purification ; metabolism ; Biotransformation ; Culture Techniques ; Cunninghamella ; metabolism ; Diterpenes ; isolation & purification ; metabolism ; Mucor ; metabolism ; Plants, Medicinal ; chemistry ; Proteus vulgaris ; metabolism ; Taxus ; chemistry