Osman Tiryaki

Adaptation and validation of QuEChERS method for the analysis of trifluralin in wind-eroded soil

This study was carried out to develop and validate a reliable analytical procedure for trifluralin analysis in wind-eroded sediments. Soil sediments trapped in BEST sediment traps were subjected to QuEChERS extraction method, incorporating a simple simultaneous cleanup step, followed by trifluralin analysis with GC-ECD. Results revealed that QuEChERS method offered a potential alternative technique for pesticide extraction from soil samples. The validity of analytical method was performed by the method-performance criteria such as, recovery, LOD, LOQ repeatability, precision, and all found to be within the required limits. It was also observed in this study that herbicide concentrations in the wind-eroded sediment did not vary with the time and trap height. Trifluralin concentrations of surface soil after four erosion events were higher (626.05 μg/kg) than wind-eroded soil (450.08 μg/kg).

Biodegradation of Trifluralin in Harran Soil

Abstract Degradation of trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) was investigated in soils taken from three different locations at Harran region of Turkey under laboratory conditions. Surface (0–10 cm) soils, which were taken from a pesticide untreated field Gürgelen, Harran-1 and Ikizce regions in the Harran Plain, were incubated in biometer flasks for 350 days at 25°C. Ring-UL-14C-trifluralin was applied at the rate of 2 µg g−1 with 78.7 kBq radioactivity per 100 g soil flask. Evolved 14CO2 was monitored in KOH traps throughout the experiment. Periodically, soil sub-samples were removed and extracted by supercritical fluid extraction (SFE). Unextractable soil-bound 14C residues were determined by combustion. During the 350 days incubation period 6.6, 5.4, and 3.3% of the applied radiocarbon was evolved as 14CO2 from the Harran-1, Gürgelen, and Ikizce soil, respectively. At the end of 350 days the SFE-extractable and bound 14C-trifluralin residues were 39.0 and 29.2% of the initially applied herbicide in Gürgelen soil. The corresponding values for Harran-1 and Ikizce soils were 36.2, 28.4% and 41.6, 18.5% respectively.

Parazitli Spodoptera littoralis Boisd. larvalarında 14C-Aldicarbın İzlenmesi

This study was carried out to determine the fate of 14C-aldicarb in parasitized Spodoptera littoralis Boisd (Lep.: Noctuidae) larvae fed with 14C-aldicarb treated lettuce leaves. 14C-aldicarb equivalent residues were found 75.49 % , 1.14 % and 3.4 % of initially applied radioactivity in the feces of Spodoptera littoralis and cadaver, and parasitoid (Chelonus oculator Panzer Hym.:Braconidae), respectively. Results showed that aldicarb metabolized rapidly and excreted out of body by feces within 24-48 hours, before the attack of parasitoid to host organs.

The effect of food processing on 14C‐trifluralin residues in carrot

Abstract Carrots were grown in a soil treated with the herbicide trifluralin labeled with 14C at the rate of 0.84 kg/ha. The total 14C‐residues in washed and unwashed carrots as well as in peel and pulp were determined. Higher concentration of 14C residues was found in the peel than in the pulp. Unwashed carrots contained more 14C residues than the washed carrots and the amount of 14C residue was higher in phloem than in xylem. The proportion of the total 14C residues content in carrot was also higher in juiced, boiled, and fried carrots.