A sensitive catalytic spectrophotometric method for the determination of ruthenium （Ⅲ） has been developed, based on its catalytic effect on the oxidation reaction of methyl green with potassium bromate in acid solu...A sensitive catalytic spectrophotometric method for the determination of ruthenium （Ⅲ） has been developed, based on its catalytic effect on the oxidation reaction of methyl green with potassium bromate in acid solution medium at 100℃. The above reaction is followed spectrophotometrically by measuring the decrease in the absorbance at 625 nm for the catalytic reaction of methyl green. The calibration curve for the recommended reaction-rate method was linear in the concentration range over 0.00-0.80 μg/L and the detection limit of the method for Ru （III） is 0.006 μg/L. Almost no foreign ions interfered in the determination at less than 25-fold concentration of Ru （Ⅲ）. The method is highly sensitive, more selective and very stable, and has been successfully applied for the determination of trace ruthenium in some ores and metallurgy products.展开更多
The toxicity of methyl tert-butyl ether （MTBE） to Chlorella ellipsoidea and Aphanizomenon flos-aquae was tested and assessed for a 15-d incubation with concentrations of MTBE from high （2.00×10^4 mg/L） to low...The toxicity of methyl tert-butyl ether （MTBE） to Chlorella ellipsoidea and Aphanizomenon flos-aquae was tested and assessed for a 15-d incubation with concentrations of MTBE from high （2.00×10^4 mg/L） to low （2 mg/L）. The results showed that the toxicity was low when the concentration of MTBE was in the range 1.00× 10^4-2.00× 10^4 mg/L （the greatest inhibition of growth-rate was 70%-71%, occurred during the day 1-5）. Low concentrations （2-500 rag/L） stimulated algal growth up to the greatest effect of 85%-200% when the concentration of MTBE was 50-100 mg/L during day 3-5. The toxicity of MTBE （72-120 h EC50） was 6.65×10^3-9.58×10^3 mg/L for C. ellipsoidea and that is 1.14× 10^4-2.00× 10^4 mg/L for A. floc-aquae. We found that the toxicity and ecological risk of MTBE for the algal community structure were low and the toxicity was influenced by the duration time of the test.展开更多
采用甲基绿吸收光谱法同时测定糖果中酒石黄和日落黄含量,并对不同糖果前处理及甲基绿吸收光谱法检测条件进行单因素优化。结果表明,不同糖果前处理条件略有差异。在400~800 nm范围内,Tris-HCl用量1 m L,p H为9.43,甲基绿溶液用量2 m L...采用甲基绿吸收光谱法同时测定糖果中酒石黄和日落黄含量,并对不同糖果前处理及甲基绿吸收光谱法检测条件进行单因素优化。结果表明,不同糖果前处理条件略有差异。在400~800 nm范围内,Tris-HCl用量1 m L,p H为9.43,甲基绿溶液用量2 m L,反应时间15 min时,甲基绿与酒石黄和日落黄发生显色反应生成离子缔合物,酒石黄-甲基绿在574 nm处测得最大值,标准曲线为y=-0.0035x+0.7009(R^(2)=0.9993),线性范围是0.03~16 mg/L,检出限为0.069 mg/L;日落黄-甲基绿在488 nm处测得最大值,标准曲线为y=0.0378x+0.2104(R^(2)=0.9993),线性范围是0.04~14 mg/L,检出限为0.024 mg/L。对实际样品进行加标回收,酒石黄与日落黄的加标检测均在正常范围内。该方法简便、快速、灵敏度高,可以在不同波长下同时测定硬质糖果中的酒石黄和日落黄的含量。展开更多
Promoted and mediated by an ionic liquid-[bmim][BF4], fused pyrans or arylbis（4-hydroxy-6-methyl-2-oxo-2H-pyran-3- yl）methanes were efficiently and selectively prepared from the reaction of aldehyde and 4-hydroxy-6-...Promoted and mediated by an ionic liquid-[bmim][BF4], fused pyrans or arylbis（4-hydroxy-6-methyl-2-oxo-2H-pyran-3- yl）methanes were efficiently and selectively prepared from the reaction of aldehyde and 4-hydroxy-6-methyl-2-oxo-pyran with or without acetic anhydride. By using these novel procedures, pyrimidine nucleoside-fused pyran and arylbis（pyranon-3-yl）methane hybrids with potential biological activities were constructed.展开更多
基金Project 0520002 supported by Natural Science Foundation of Jiangxi Province, China
文摘A sensitive catalytic spectrophotometric method for the determination of ruthenium （Ⅲ） has been developed, based on its catalytic effect on the oxidation reaction of methyl green with potassium bromate in acid solution medium at 100℃. The above reaction is followed spectrophotometrically by measuring the decrease in the absorbance at 625 nm for the catalytic reaction of methyl green. The calibration curve for the recommended reaction-rate method was linear in the concentration range over 0.00-0.80 μg/L and the detection limit of the method for Ru （III） is 0.006 μg/L. Almost no foreign ions interfered in the determination at less than 25-fold concentration of Ru （Ⅲ）. The method is highly sensitive, more selective and very stable, and has been successfully applied for the determination of trace ruthenium in some ores and metallurgy products.
基金supported by the National Natural Science Foundation of China (No. 20476099)
文摘The toxicity of methyl tert-butyl ether （MTBE） to Chlorella ellipsoidea and Aphanizomenon flos-aquae was tested and assessed for a 15-d incubation with concentrations of MTBE from high （2.00×10^4 mg/L） to low （2 mg/L）. The results showed that the toxicity was low when the concentration of MTBE was in the range 1.00× 10^4-2.00× 10^4 mg/L （the greatest inhibition of growth-rate was 70%-71%, occurred during the day 1-5）. Low concentrations （2-500 rag/L） stimulated algal growth up to the greatest effect of 85%-200% when the concentration of MTBE was 50-100 mg/L during day 3-5. The toxicity of MTBE （72-120 h EC50） was 6.65×10^3-9.58×10^3 mg/L for C. ellipsoidea and that is 1.14× 10^4-2.00× 10^4 mg/L for A. floc-aquae. We found that the toxicity and ecological risk of MTBE for the algal community structure were low and the toxicity was influenced by the duration time of the test.
基金the National Natural Science Foundation of China(No.20772025)the Program for Science & Technology Innovation Talents in Universities of Henan Province(No.2008HASTIT006)the Natural Science Foundation of Department of Education of Henan Province(No.2008A150013).
文摘Promoted and mediated by an ionic liquid-[bmim][BF4], fused pyrans or arylbis（4-hydroxy-6-methyl-2-oxo-2H-pyran-3- yl）methanes were efficiently and selectively prepared from the reaction of aldehyde and 4-hydroxy-6-methyl-2-oxo-pyran with or without acetic anhydride. By using these novel procedures, pyrimidine nucleoside-fused pyran and arylbis（pyranon-3-yl）methane hybrids with potential biological activities were constructed.
