Pesticide Residues In Soil-plant System And The Combined Pollution's Bioeffects

In this paper, SPE that is commonly used to pretreat water samples when analyzing organic pollutants is introduced to the pretreatment of soil and agro-products, including rice, fruits and vegetables, in order to purify and concentrate these samples before analyze pesticide multi-residues with CGC-NPD. An off-line method of SPE-CGC method that is applicable to daily analysis of pesticide multi-residues of large quantities of soil and agro-products samples is founded in this paper. Then, this method is used to real soil and agro-product samples' pesticide multi-residues analysis. Through bulk case studies, the situation of pesticide residues in real environment is detected and analyzed. On this basis, the pesticides combined pollution's toxic effects to aquatic creature, zebra fish (Brachydanio rerio), are studied.The target pesticides' chromatographic peaks' separation and distribution, their linearity, relative standard deviation (RSD) and fortified recovery is studied. The result shows that this analysis method is fast, economical, exact and credible, which can meet the requirement of bulk samples' pesticide multi-residues analysis in ordinary domestic laboratories.The statistical results of pesticide multi-residues in large quantities of soil and agro-products' samples show that some familiar pesticides that are commonly used can be detected in the soil and agro-product samples analyzed. The detected commonly used pesticides in soil samples are, Dichlorovos, Acephate, Omethoate, Triazophos, Phorate, Dimethoate, Carbofuran, Parathion-methyl and Parathion. The number of detected commonly used pesticides in fruits and vegetable samples is six, they are Methamidaphos, Dichlorovos, Dimethoate, Parathion, Carbendazin and Triadimefon. Among them, because of virulent property, Methamidaphos and Parathion are forbidden to be applied to fruits and vegetables, while they can still be detected. There are 4 commonly used pesticides are detected in rice samples, they are Methamidaphos, Dichlorovos, Parathion-methyl and Parathion. In addition, the two organochlorine pesticides HCHs and DDTs residues can be detected in both soil andrice samples. Though if compare to related regulations the concentrations are far below the MRLs, their detection rate are very high. Therefore, the situation of persistent organochlorine pesticide residues should be highly concerned.From the analysis of pesticide residues in soil and agro-product samples, it can be obviously observed that the pesticide multi-residues are ordinarily occurred in environment. So, in real environment, to study combined pesticide pollution is of great importance for the right solutions to pollution problems and decision-making. Therefore, in the third part of this paper, the combined toxic effect of organochlorine pesticide - Lindan, organophosphorus pesticide -Parathion-methyl and aminoformin pesticide - Carbofuran by twos are studied. Among the four groups, except one group - that is the group fixing the concentration of Parathion-methyl to 2.15mg/L and set five different levels of Carbofuran - cannot be observed to get obvious increase on toxic effect to zebra fish, the other 3 groups' toxic effect are highly reinforced.