Simple procedures for extraction and chromatographic determination of dimethachlon residues in fresh tobacco leaves and cut-tobacco are described.The determination was carried out by capillary gas chromatography(GC) w...Simple procedures for extraction and chromatographic determination of dimethachlon residues in fresh tobacco leaves and cut-tobacco are described.The determination was carried out by capillary gas chromatography(GC) with electron capture detection(ECD) and confirmed by GC-MS.The mean recoveries and relative standard deviation(RSD) were 93.2%～112.9% and 3.5%～6.7%,respectively at levels ranging from 0.01 to 0.1 mg/kg.The limit of determination was 0.001 mg/kg.Tobacco samples in routine check were successfully analyzed using the proposed method.展开更多
To clarify the suitable harvest maturity of Xiangyan 7 of the lower leaves of paddy-tobacco,the curing test of lower tobacco leaves with different maturities was carried out in Guiyang tobacco area of Hunan in China.T...To clarify the suitable harvest maturity of Xiangyan 7 of the lower leaves of paddy-tobacco,the curing test of lower tobacco leaves with different maturities was carried out in Guiyang tobacco area of Hunan in China.The results showed that the SPAD value of fresh tobacco and proportion of normal group decreased,the proportion of mottle tobacco increased,the appearance quality of tobacco leaves became worse,the level of total sugar,reducing sugar,nicotine and reducing sugar/total sugar increased,and the total nitrogen/nicotine decreased with increased harvest maturity of lower tobacco leaves.It could cause lower smoking quality,lower proportion of high-class tobacco leaves and lower average price if the harvest of lower tobacco leaves was delayed.Therefore,the lower leaves of Xiangyan 7 in Guiyang tobacco area of Hunan should be harvested early.Suitable harvest maturity required light green leaf blade,light green midrib,and curl leaf margin.When the SPAD value of fresh tobacco was 26.26~30.33,it could be used as a reference for guiding the appropriate harvest maturity of lower paddy-tobacco leaves of Xiangyan 7.展开更多
基金Project (No. 2006NG01) supported by the Agriculture Breakthrough Program of Yunnan Province, China
文摘Simple procedures for extraction and chromatographic determination of dimethachlon residues in fresh tobacco leaves and cut-tobacco are described.The determination was carried out by capillary gas chromatography(GC) with electron capture detection(ECD) and confirmed by GC-MS.The mean recoveries and relative standard deviation(RSD) were 93.2%～112.9% and 3.5%～6.7%,respectively at levels ranging from 0.01 to 0.1 mg/kg.The limit of determination was 0.001 mg/kg.Tobacco samples in routine check were successfully analyzed using the proposed method.
文摘To clarify the suitable harvest maturity of Xiangyan 7 of the lower leaves of paddy-tobacco,the curing test of lower tobacco leaves with different maturities was carried out in Guiyang tobacco area of Hunan in China.The results showed that the SPAD value of fresh tobacco and proportion of normal group decreased,the proportion of mottle tobacco increased,the appearance quality of tobacco leaves became worse,the level of total sugar,reducing sugar,nicotine and reducing sugar/total sugar increased,and the total nitrogen/nicotine decreased with increased harvest maturity of lower tobacco leaves.It could cause lower smoking quality,lower proportion of high-class tobacco leaves and lower average price if the harvest of lower tobacco leaves was delayed.Therefore,the lower leaves of Xiangyan 7 in Guiyang tobacco area of Hunan should be harvested early.Suitable harvest maturity required light green leaf blade,light green midrib,and curl leaf margin.When the SPAD value of fresh tobacco was 26.26~30.33,it could be used as a reference for guiding the appropriate harvest maturity of lower paddy-tobacco leaves of Xiangyan 7.
