摘要
研究了3,5-二溴-2-吡啶偶氮重氮氨基偶氮苯(3,5-DB-PDAB)与银的显色反应,在pH 11.0的硼砂-氢氧化钠缓冲介质中,乳化剂-OP存在下,3,5-DB-PDAB与银反应生成2∶1稳定配合物.该配合物可用pH 1～12的Waters XterraTM RP18固相萃取小柱富集,小柱上富集的配合物用含0.01mol/L pH为11.0的四氢吡咯-醋酸缓冲盐的乙醇洗脱后用光度法测定,在洗脱剂介质中λmax 526nm,摩尔吸光系数1.72×105L·mol-1·cm-1,银含量0.01～1.0g/mL范围内符合比尔定律.方法用于环境水样中银的测定.
The color reaction of silver with 3, 5-dibromo-2- pyridinediazoaminoazobenzene （ 3, 5-DB-PDAB ） was studied. Based on the color reaction of 3,5-DB-PDAB with silver（ Ⅰ ） and the solid phase extraction of its colored complex with Waters Xterra TM RP18 cartridge, a new method for the determination of silver（ Ⅰ ） was established. In pH 11.0 borax-sodium hydroxide buffer solution and emulsifier-OP medium,3,5-DB-PDAB can react with silver（ Ⅰ ） to form a stable 2 ： 1 complex. The colored complex can be extracted by Waters Xterra TM RPIs cartridge and eluted from the cartridge with ethanol（containing 0.01mol/L of pH 11 pyrrolidine-acetic acid buffer）, then determined by spectrophotometry. The molar absorptivity is 1.72 × 10^5L·mol^-1· cm^-1 at 526 nm. Beer＇s law is obeyed in the range of 0.01 - 1.0μg/mL.This method was applied to the determination of silver in water with good results.
出处
《化学试剂》
CAS
CSCD
北大核心
2005年第8期474-476,共3页
Chemical Reagents
