The procedure for simultaneous extraction from soil and determination by means of GC-ECD insecticides: aldrin, dieldrin, endrin and herbicide: atrazine was worked out. The proposed GC-ECD technique provides limits of detection in range 12 μg/mL - 18 μg/mL and 2 μg/mL, for insecticides and atrazine, respectively. Two different types of extraction: microwave assisted extraction (MAE) and ultrasound assisted extraction (UAE) with different solvents were tested to choose the procedure that provides the highest recoveries of analytes and low detection limits, typical for trace analysis (100 ppm or 100 mg/g, IUPAC). On the basis of recoveries and precision both extraction methods were compared. The insecticides recovery from soil samples obtained by UAE were in range 40-85%, coefficient of variation (CV): 1.3-5.0%, whereas for atrazine recovery was below 15% (CV: 8-18%). The most efficient and precise extraction procedure turned out to be MAE with n-hexane: acetone. The recoveries were in range 70-85% for insecticides and 84% for atrazine, CV: 0.4-2.2% and 5.3% for insecticides and atrazine, respectively. The presented MAE-GC-ECD procedure enables extraction and determination of aldrin, dieldrin, endrin and atrazine in soil samples with high recoveries, precision and limits of detections in range 6 ng/g - 8 ng/g in the case of insecticides and 1.5 ng/g for atrazine.
The MAE-GC-ECD procedure was applied for the above mentioned pesticides determination in environmental samples. Soils were collected in agricultural as well as rural areas in Poland. In all cases atrazine was determined in concentration range: 0.0187 mg/g - 0.1107 mg/g. Aldrin and dieldrin was detected in soil samples from two locations.
The pesticide persistence, in particular in soils, often significantly exceeding the declarations of their manufacturers is surprising. There are many publications devoted to the explanation of this phenomenon in the field literature, but the diverse research methodologies used may lead to the ambiguous conclusions. On the basis of the collected literature, the attempt was made to systematize the available information on the interactions of commonly used groups of pesticides with individual soil components. The complex mechanisms of interactions between pesticides and soil based on van der Waals forces, ionic and covalent bonding, ligand exchange and charge transfer complexes formation were demonstrated. It was also proved that the nature of interactions is strictly dependent on the structure of the pesticide molecule. The conclusion of the review may contribute to the choice of plant protection products that, in addition to their effectiveness, are as little ballast for the environment as possible.
The aim of this study was to monitor pesticide residues in the blood of agricultural workers (farmers, pesticide dealers, and spraying workers) living in the Dakahlia Governorate, Egypt. Residue analysis revealed that 48, 76, and 84% of the farmers, pesticide dealers, and spraying workers had pesticide residues in their bloods, respectively. Eleven compounds were detected in the blood of examined individuals. According to the World Health Organization (WHO) classification, most of these pesticides (nine pesticides) were in moderately hazardous compounds. Carbofuran, a highlyhazardous compound was the most toxic. The compound with the lowest toxicity was hexytiazox, which is unlikely to pose an acute hazard in normal use. Chlorpyrifos was found in the blood of 38.3% of the study subjects, followed by acetamiprid (11.7%) and profenofos (10.7%), while fenvalerate was the lowest occurring compound (1.3%). Of the collected samples 41.3% was free of pesticide residues, while 58.7% of the samples was contaminated. Furthermore, the amounts of all detected pesticides were below the no observable adverse effect levels (NOAEL). Also, 38.7% of the samples had only one pesticide, while 8% of them contained residues of two pesticides, and 5.3% contained more than two compounds. The worker’s age did not affect the accumulations of pesticide residues in their bodies. However, there was a strong correlation between pesticide residues accumulation and an individual’s exposure time. Therefore, from these results it can be seen that encouraging greater awareness among pesticide users of the need to improve safe usage and handling of pesticides by education, advice, and warning them of the risks involved in the misuse of these poisonous materials is highly recommended.
The study was conducted at the University of Nebraska Pesticide Application and Technology Laboratory in North Platte, Nebraska in July 2015. Two application volume rates (100 and 200 l · ha−1) and three nozzle types (XR, AIXR, TTI) were selected at two flow rates (0.8 and 1.6 l · min−1) and at a single application speed of 7.7 km · h−1. Each collector type [Mylar washed (MW), Mylar image analysis (MIA), water-sensitive paper (WSP), and Kromekote (KK)] was arranged in a randomized complete block design. Each nozzle treatment was replicated twice, providing six cards of each collector type for each nozzle treatment. A water + 0.4% v/v Rhodamine WT spray solution was applied, given the fluorescent and visible qualities of Rhodamine, which allows it to be applied over all the collector types. MW had the highest coverage at 18.3% across nozzle type, followed by WSP at 18%, KK at 12% and lastly by MIA at 4%. MW resulted in a 58% increase in coverage, WSP in a 56% increase, and KK only an increase of 39% when the volume rate was doubled from 100 l · ha−1 to 200 l · ha−1 across nozzle type. MW coverage was similar to KK for half of the nozzles (XR 11002, XR 11004, AIXR 11002). Droplet number density fixed effects were all significant for nozzle type and collector type (p < 0.001) as was the interaction of nozzle type and collector type (p < 0.001). Results from this study suggest a strong correlation to data produced with WSP and MW collectors, as there was full agreement between both types except for the TTI 11004. Using both collector types in the same study would allow for a visual understanding of the distribution of the spray, while also giving an idea of the concentration of that distribution.
en
pl
