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

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

应用高效的在线流动注射赘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中痕量铅。实验用内装 ２００ｍｇ Ａｍｂｅｒｌｉｔｅ ＸＡＤ－４键合的 ５－碳酸－８－羟基喹淋螯合树脂的锥形柱，在 ｐＨ ９条件下样品流速为 ８．０ ｍＬ／ｍｉｎ，９０ ｓ采样，用 ０．５ ｍｏｌ／Ｌ ＨＣＩ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 １μ／Ｌ。铅含量水平５０μｇ／Ｌ的水样连续测定 １１次的相对标准偏差为 ２．５％，可直接测定水体中μｇ／Ｌ级的铅。

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.