探讨了顶空气相色谱法测定水中三氯乙醛的条件控制，阐述了加碱量对测定结果的影响，以及加热温度过高或加热时间过长导致三氯甲烷响应值变低的原因。结果表明，在5．0 mL水样中加入0．4 mL 5 mol/L NaOH水溶液，于45℃条件下加热30 min，可使目标产物三氯甲烷的响应值及稳定状态达到最佳。方法在2．00μg/L～30．0μg/L范围内线性良好，检出限为0．5μg/L。对三氯甲烷背景浓度较高的自来水样品的加标回收率为88．3％～105％，RSD为6．3％。%The keys were discussed on controlling the conditions of automatic headspace gas chromatograph -ic method for chloral hydrate determination in water .The effect of NaOH concentration on quantitative result was studied.The reasons were stated why the response of trichloromethane (CHCl3) decreased when extremely high temperature or the excessive long time of heating was performed .The results showed when a 0.4 mL 5 mol/L NaOH solution was added to the sample , and equilibrating at 45 ℃ for 30 minutes , the response of CHCl 3 reached its high point.The method detection limit come to be 0.5μg/L.The RSD of replicate standard solution was 8.5%.Spiked recoveries of tap water with high background of CHCl 3 ranged from 88.3%to 105%, with an RSD of 6.3%.
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