超声萃取-气相色谱法测定芒果园土壤中多效唑残留量

Determination of Paclobutrazol Residue in Soil of Mango Garden by Ultrasonic Extraction-GC Method

[目的]研究超声萃取芒果园土壤中多效唑残留量的毛细管气相色谱检测方法。[方法]采用超声波振荡从经丙酮浸泡的样品中提取多效唑,然后通过装有无水硫酸钠的带滤纸的漏斗过滤后,浓缩、定容,上气相色谱仪测定。利用正交试验确定了多效唑的提取条件。以多效唑标准溶液的浓度为横坐标,峰面积为纵坐标,绘制线性关系曲线,对测定结果进行线性相关分析。[结果]正交试验表明,多效唑的最佳提取条件是：提取液用量为50 m l,浸提时间为24 h,超声时间为60 m in。标准曲线表明,线性关系良好。多效唑添加水平为0.064、0.128、0.256、1.000 mg/kg时,方法的回收率为96.3%～106.0%,相对标准偏差（RSD）为2.8%～5.7%,最低检出限为0.010mg/kg。[结论]采用该方法测定土壤中多效唑的残留量,操作简便、快捷、准确,达到了残留分析的要求。

[Objective] The aim was to research the detection method of capillary gas chromatography on paclobutrazol residue in the soil of mango garden by ultrasonic extraction.[Method] Paclobutrazol was extracted from the acetone-dipped sample by ultrasonic extraction,which was filtrated by the filler with loading the filter paper of anhydrous sodium sulfate,condensed,constanted in volume,measured by gas chromatography.The orthogonal test was used to make sure the extraction condition of paclobutrazol.With the concn.of paclobutrazol standard solution as abscissa and the peak area as ordinate,the linear relationship curve was drawn and the linear correlation analysis on determination result was made.[Result] The orthogonal test showed that the optimum extraction condition of paclobutrazol was as that the extraction fluid volume was 50 ml,extraction time was 24 h,ultrasonic time was 60 min.The standard curve showed that the relationship of linear was good.When the adding level of paclobutrazol was 0.064,0.128,0.256,1.000 mg/kg,the method recovery was 96.3%-106.0%,the relative standard deviation（RSD） was 2.8%-5.7%,the lowest detection limit was 0.010 mg/kg.[Conclusion] This detection method was used to measure the paclobutrazol residue in the soil,which was simple in operation,rapid in speed,accurate in result and reached the requirement of residue analysis.