The Minjiang River basin is an important ecological barrier and water conservation area in the upper reaches of the Yangtze River.As the largest first-order tributary of the Yangtze River,the Minjiang River's organic pollution status deserves more attention.This study collected river sediments from 21 sites along the upper and middle reaches of the Minjiang River and,for the first time,systematically analyzed the characteristics of 40 pesticides using ultrasound-assisted extraction followed by gas chromatography-mass spectrometry.Through correlation analysis and principal component analysis,the study investigated the pollution characteristics of 40 pesticides in the sediment of the Minjiang River.In this study,35 pesticides from 8 classes were detected,including 11 pyrethroids,9 organophosphates,6 organochlorines,and 3 dichlorobenzenes,with detected concentrations ranging from 0.2 ng·g-1 to 633.9 ng g-1 dw.Pyrethroids and dichlorobenzenes contributed to 64.6％of the total concentration of pesticides.Significant differences in the types and concentrations of pesticides were found between the upper(Minjiang Source-Dujiangyan)and middle(Dujiangyan-Minjiang Bridge)reaches of the Minjiang River,i.e.,9 pesticides vs.35 pesticides,0.7-100.0 ng g-1 dw vs.0.2-633.9 ng·g-1 dw.Principal component analysis suggested that pesticide pollution characteristics were different between the upper and middle reaches of the Minjiang River,primarily due to differences in the concentrations of pyrethroids and organophosphates.Correlation analysis revealed that pyrethroids may have a common source.In addition to agricultural non-point source pollution,non-point source pesticides from urban parks and green spaces should also be given attention.The results also indicated that concentrations of pyrethroids decreased along the river flow in some specific sections of the Minjiang River,suggesting that they may undergo a certain degree of degradation.
维普
万方数据