在线流动注射螯合树脂预富集石英缝管增敏火焰原子吸收法测定水中痕量铅

应用高效的在线流动注射螯合树脂预富集石英缝管增敏火焰原子吸收系统直接测定水呈痕量铅。实验用内装２００ｍｇＡｍｂｅｒｌｉｔｅＸＡＤ－４键合的５－磺酸－８羟基喹啉螯合树脂的锥形柱，在ＰＨ９条件下样品流速为８．０ｍＬ／ｍｉｎ，９０ｓ采样，用０．５ｍｏｌ／Ｌ Ｈｃｌ洗脱，在分析速度为３０样／ｈ，获得３６倍的富集，经石英缝管增敏，灵敏度提高达１１５倍，线性范围为０－２００μｇ／Ｌ，检出限为１μｇ／Ｌ。铅含量水平５０μｇ／Ｌ的水样连续测定１１次的相对标准偏差２．５％，可直接测定水体中μｇ／Ｌ级的铅。

Flow-Injection Quantification of Trace Lead in Water by On-line Preconcentration-Flame Atomic Absorption Spectrometry

Flow-injection flame atomic absorption spectrometry (FIA-FAAS) with the slotted quartz tube has been applied to determine lead in water via on-line preconcentration with chelating resin. Water sample mixed with the pH buffer (pH 9.0) was pumped through a conical column packed with 200 mg poly(8-HQ-SO3H) chelate resin and the lead in water sample was absorbed and then eluted into the nebulizer of AAS with a soltted quartz tube using 0.5 mol/L HCI. A linear response for 5 ug/L to 200 ug/L and a detection limit of 1 ug/L were achieved. This system improved the sensitivity of Pb by a factor of 115 compared with conventional FAAS. The proposed method has been successfully applied to the direct measurement of lead in drinking water at a sampling frequency of 30/h.