AnAlyticAl support of hygienic control of ОXAthiApiprolin residual amounts in environmental objects and potatoes

for of Optimal conditions of oxathiapiprolin chromatography were established: mobile phase – acetonitrile mixture + bidistilled water (75+25), UV detector wavelength – 260 nm, thermostat column temperature – 30 °С. Retention time – 4.6±0.1 minutes. Linear detection range is 0.5–10.0 mg/ml. Dependence of calibration area (S) peaks of the substance on its concentration (ρ) described by linear regression equation: S oxathiapiprolin =272.4+36315.7×ρ. The best results are obtained when concentrating the air on a filter paper “blue ribbon” followed by extraction with acetone. When choosing extractants to оxathiapiprolin determination in water, the best result obtained with ethylacetate; soil – with acetone, potatoes – with a mixture of acetonitrile + 0.5 % aqueous phosphoric acid, followed by purification of extracts by adsorption. Conclusions. Thus, developed analytical methods meet modern requirements, are selective and allow to control oxathiapiprolin content in water at detection limit level – 0.002 mg/dm 3 , air of working zone – 0.2 mg/m 3 , atmosphere air – 0.003 mg/m 3 , soil – 0.03 mg/kg, potato – 0.003 mg/kg.

INTRODUCTION. Providing of analytical control over the application of pesticides in environmental objects and agricultural products -is a mandatory component of preregistration studies of new chemical plant protection products.
On the pesticide market new compound оxa thiapiprolin has appeared. The substance belongs to new piperidinylthiazoleisoxazoline chemical class pesticides with new mode of action. It effectively inhibits the growth of mycelium, has exceptionally oomycete activity and causes inhibition of oxysterolbinding proteins [1,2].
Specialists of the Institute of Plant and Environmental Protection, Peking Academy of Agriculture and forestry Sciences developed efficient and sensitive method for quantification of оxathiapiprolin residual amounts in foods using ultra performance liquid chromatography coupled with mass spec-trometry [3]. Expensive equipment and complexity of this method realization limit its use in Ukraine. Therefore, the most common for pesticides application control is a method of high performance liquid chromatography (HPLC) [4][5][6].
Given the above, the aim of the study -to develop analytical methods for оxathiapiprolin determination in the air, water, soil and potatoes for hygiene monitoring of compliance with hygienic standards in the environment and agricultural raw materials during the application of fungicides based on рiperidinylthiazoleisoxazolines. RESULTS AND DISCUSSION. On the first stage of the study we conducted a series of experiments to establish optimal conditions for оxathiapiprolin chromatography, given in Table 1.

RESEARCH
In the selection of the mobile phase, a series of studies in acetonitrile+bidistilled water systems in various combinations (85+15, 75+25 and 65+35, vol.+vol.) were conducted. To determine the optimal wavelength detection, we studied wavelength range from 220 to 300 nm.
On the next stage of research calibration curve was constructed ( Fig. 1), range in which there is a linear relationship between peak area and оxa thiapiprolin concentration was determined. Calibration curve was constructed in accordance with international standard [7].
Also, we conducted a series of laboratory experiments on the selection of extractants for the removal of the substance from the air, water, soil, potatoes samples and determining of the most effective way of extracts samples purification. At the stage of extractants selection the following organic solvents have been used -methanol, acetonitrile, acetone, chloroform, hexane, ethylacetate, dichloromethane, and combinations thereof.
As a result of the studies optimal conditions for extraction and purification, which provide selective removal of the test compound from matrices without impurities that interfere with chromatographic determination were set.
Air samples were taken on various sorption materials; the best results are obtained when concentrating the air on a filter paper "blue ribbon". After оxathiapiprolin concentration from air on sorp- CONCLUSIONS. Thus, developed analytical methods meet modern requirements, are selective and allow to control oxathiapiprolin content in different objects and can be used for air of working zone, atmosphere air, water and soil safety control during the application of pesticides based on рiperidinylthiazoleisoxazoline class compound. Note. * -LOQ -limit of quantification, DL -limit of detection.
tion materials, the best extraction of material from sorbent was carried out with acetone.
When choosing extractants to оxathiapiprolin determination in water, the best result obtained with ethylacetate. Best оxathiapiprolin extraction from soil samples was carried out with acetone, potatoes -with a mixture of acetonitrile + 0.5 % aqueous phosphoric acid, followed by purification of extracts by means of adsorption chromatography ( Table 2).
The obtained extracts of air and water samples after extraction and purification were dried with anhydrous sodium sulfate 20-25 g by infusion in a conical flask of 250 ml volume for 30 minutes. The extract was filtered through a filter "red tape" in the pearshaped flask for solvent distillation with a capacity 250 ml, sodium sulfate and filter were washed with 20 ml of extractant. Eluates from soil and potato samples were collected in pear-shaped flask for solvent distillation (50-100 ml). The combined extracts and eluates was evaporated on a rotary evaporator at water bath temperature no higher than 40 °С to volume 0.2-0.3 ml. The solvent residue was evaporated on air. The dry residue was quantitatively transferred to a graded test tube with a 10 ml capacity using acetonitrile. The final volume of the extract of air, water and soil samples was 2 ml potatoes -1 ml.
Metrological characteristics of oxathiapiprolin determination in environmental objects and agricultural raw materials by HPLC are given in Table 3.