摘要：

采用原位盐脱水-顶空气相色谱技术对煤焦化废水中的苯酚含量进行了测定。废水经脱水盐吸收后其所含苯酚自然由水相进入气相,用顶空-气相色谱仪进行检测。结果表明:无水氯化钙脱水效果较好;5.2 g无水氯化钙在90℃平衡12 h可完全吸收500 μL样品中的水分;顶空分析的平衡温度为150℃、时间为30 min时可达到苯酚的全气化;该方法平行检测的相对标准偏差为4.0%,最低检测极限为3.25 μg,回收率在91.1%~104%。方法操作简单、准确性高、无试剂干扰,适于检测煤焦化废水中的苯酚含量。

关键词: 原位盐脱水, 顶空气相色谱, 煤焦化废水, 苯酚, 无水氯化钙

Abstract:

An in-situ salt-dehydration headspace gas chromatography technique has been used for the determination of phenol content in coking wastewater. After the wastewater has been absorbed by anhydrous salt,its phenol content can naturally be converted from aqueous phase into vapor phase,and then be analyzed by headspace gas chromatography. The results show that anhydrous CaCl₂ has better dewatering effect. The addition of 5.2 g of anhydrous CaCl₂ could fully absorb 500 μL of water from the sample in an oven at equilibrium temperature 90℃ for 12 h. When the equilibrium temperature of headspace analysis is 150℃,phenol can be fully evaporated in 30 min. The relative standard deviation of parallel detection of this method is 4.0%,the lowest detection limit 3.25 μg,and the recovery rate is ranged from 91.1% to 104%. The method is characterized by simple operation,high accuracy,and no reagent interference,and suitable for the determination of phenol content in coking wastewater.

Key words: in-situ salt-dehydration, headspace gas chromatography, coking wastewater, phenol, anhydrous CaCl₂

中图分类号: 

• X703.1