The mechanism of nitrocompounds quenching of the fluorescence of 5, 5′ dipheny1 2, 2′ bisoxazole (POOP) and trans 1, 2 bis [2 (5 phenyloxazolyl)] ethene (POEOP) has been studied. It was found that the fluores...The mechanism of nitrocompounds quenching of the fluorescence of 5, 5′ dipheny1 2, 2′ bisoxazole (POOP) and trans 1, 2 bis [2 (5 phenyloxazolyl)] ethene (POEOP) has been studied. It was found that the fluorescence of oxazoles was quenched mainly by the absorption competition and radiationless energy transfer of nitrocompounds. The fluorescence quenching rate constants of nitrobenzene and nitromethane are 3.0×10 10 L·mol -1 ·s -1 and 1.5×10 8 L·mol -1 ·s -1 respectively for POEOP. This remarkable difference was explicated.展开更多
文摘The mechanism of nitrocompounds quenching of the fluorescence of 5, 5′ dipheny1 2, 2′ bisoxazole (POOP) and trans 1, 2 bis [2 (5 phenyloxazolyl)] ethene (POEOP) has been studied. It was found that the fluorescence of oxazoles was quenched mainly by the absorption competition and radiationless energy transfer of nitrocompounds. The fluorescence quenching rate constants of nitrobenzene and nitromethane are 3.0×10 10 L·mol -1 ·s -1 and 1.5×10 8 L·mol -1 ·s -1 respectively for POEOP. This remarkable difference was explicated.
文摘采用正己烷作为萃取剂,采用液液萃取-气相色谱法对水样中的硝基苯类化合物进行测定,采用保留时间定性,外标标准曲线法定量,该法分析时间短,准确度好(5种物质的平均加标回收率介于93.9-105.7%),精密度高(RSD均小于5%),易于操作;同时还对萃取条件(萃取剂用量、萃取次数、萃取时间、无机盐添加量)进行优化,结果表明,萃取回收率最高的萃取剂用量为5 mL、萃取次数为2次、萃取时间为1.5 min、NaCl用量为10 g.