Instituto de Química, Universidade de São Paulo, 05513-970, PO Box 26077, São Paulo, SP, Brazil.
Talanta. 2010 Apr 15;81(1-2):327-33. doi: 10.1016/j.talanta.2009.12.005. Epub 2009 Dec 16.
An environmentally friendly analytical procedure with high sensitivity for determination of carbaryl pesticide in natural waters was developed. The flow system was designed with solenoid micro-pumps in order to improve mixing conditions and minimize reagent consumption as well as waste generation. A long pathlength (100 cm) flow cell based on a liquid core waveguide (LCW) was employed to increase the sensitivity in detection of the indophenol formed from the reaction between carbaryl and p-aminophenol (PAP). A clean-up step based on cloud-point extraction was explored to remove the interfering organic matter, avoiding the use of toxic organic solvents. A linear response was observed within the range 5-200 microg L(-1) and the detection limit, coefficient of variation and sampling rate were estimated as 1.7 microg L(-1) (99.7% confidence level), 0.7% (n=20) and 55 determinations per hour, respectively. The reagents consumption was 1.9 microg of PAP and 5.7 microg of potassium metaperiodate, with volume of 2.6 mL of effluent per determination. The proposed procedure was selective for the determination of carbaryl, without interference from other carbamate pesticides. Recoveries within 84% and 104% were estimated for carbaryl spiked to water samples and the results obtained were also in agreement with those found by a batch spectrophotometric procedure at the 95% confidence level. The waste of the analytical procedure was treated with potassium persulphate and ultraviolet irradiation, yielding a colorless residue and a decrease of 94% of total organic carbon. In addition, the residue after treatment was not toxic for Vibrio fischeri bacteria.
开发了一种用于测定天然水中克百威农药的环保分析方法，灵敏度高。该流路系统采用电磁阀微泵设计，以改善混合条件并最小化试剂消耗和废物生成。采用基于液芯波导（LCW）的长光程（100 cm）流通池，以提高检测由克百威与对氨基酚（PAP）反应形成的靛酚的灵敏度。探索了基于浊点萃取的净化步骤，以去除干扰有机物，避免使用有毒有机溶剂。在 5-200 μg L（-1）范围内观察到线性响应，检测限、变异系数和采样率分别估计为 1.7 μg L（-1）（99.7%置信水平）、0.7%（n=20）和 55 次/小时。试剂消耗量为 1.9 μg PAP 和 5.7 μg 高碘酸钾，每次测定的流出物体积为 2.6 mL。该方法对克百威的测定具有选择性，不受其他氨基甲酸酯农药的干扰。向水样中添加克百威的回收率在 84%和 104%之间，在 95%置信水平下，与批量分光光度法得到的结果一致。分析方法的废物用过硫酸钾和紫外线照射处理，得到无色残渣，总有机碳减少 94%。此外，处理后的残渣对发光菌 Vibrio fischeri 无毒性。
