College of Agriculture, Hebei University of Engineering, Handan 056038, PR China.
Chemosphere. 2011 Feb;82(6):901-4. doi: 10.1016/j.chemosphere.2010.10.053. Epub 2010 Nov 11.
The fate of pymetrozine was studied in rice field ecosystem, and a simple and reliable analytical method for determination of pymetrozine in soil, rice straw, paddy water and brown rice was developed. Pymetrozine residues were extracted from samples, cleaned up by solid phase extraction (SPE) and then determined by high-performance liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS-MS). The average recovery was 81.2-88.1% from soil, 83.4-88.6% from rice straw, 87.3-94.1% from paddy water and 82.9-85.3% from brown rice. The relative standard deviation (RSD) was less than 15%. The limits of detection (LODs) of pymetrozine calculated as a sample concentration were 0.0003 mg kg(-1) (mg L(-1)) for soil and paddy water, 0.001 mg kg(-1) for brown rice and rice straw. The results of kinetics study of pymetrozine residue showed that pymetrozine degradation in water, soil, and rice straw coincided with C=0.194e(-0.986t), C=0.044e(-0.099t), and C=0.988e(-0.780t), respectively; the half-lives were about 0.70 d, 7.0 d and 0.89 d, respectively. The degradation rate of pymetrozine in water was the fastest, followed by rice straw. The highest final pymetrozine residues in brown rice were 0.01 mg kg(-1), which was lower than the EU's upper limit of 0.02 mg kg(-1) in rice. Therefore, a dosage of 300-600 g a.i.hm(-2) was recommended, which could be considered as safe to human beings and animals.
研究了吡丙醚在稻田生态系统中的命运，建立了一种简单可靠的分析方法，用于测定土壤、稻草、稻田水和糙米中的吡丙醚。吡丙醚残留从样品中提取，通过固相萃取（SPE）进行净化，然后通过高效液相色谱-电喷雾串联质谱（LC-ESI-MS-MS）进行测定。从土壤中平均回收率为 81.2-88.1%，从稻草中为 83.4-88.6%，从稻田水中为 87.3-94.1%，从糙米中为 82.9-85.3%。相对标准偏差（RSD）小于 15%。吡丙醚的检出限（LODs）按样品浓度计算为 0.0003 mg kg(-1)（mg L(-1))）土壤和稻田水，0.001 mg kg(-1)糙米和稻草。吡丙醚残留动力学研究结果表明，吡丙醚在水中、土壤和稻草中的降解符合 C=0.194e(-0.986t)、C=0.044e(-0.099t)和 C=0.988e(-0.780t)；半衰期分别约为 0.70 d、7.0 d 和 0.89 d。吡丙醚在水中的降解速度最快，其次是稻草。糙米中吡丙醚的最终残留量最高为 0.01 mg kg(-1)，低于欧盟规定的大米中 0.02 mg kg(-1)的上限。因此，推荐使用 300-600 g a.i.hm(-2)的剂量，这对人类和动物是安全的。
