DISSIPATION PROFILE OF AZOXYSTROBIN IN SOIL AS INFLUENCED BY TEMPERATURE, SOLAR RADIATION, AND SOIL CHARACTERISTIC

INDRA PURNAMA, Prof. Dr. Bambang Rusdiarso, DEA; Prof. Dr. Sri Noegrohati, Apt

2015 | Tesis | S2 Ilmu Kimia

Telah dilakukan kajian disipasi azoxystrobin dalam tanah dengan analisis menggunakan kromatografi cair kinerja tingkat tinggi (HPLC). Ekstraksi dilakuan dengan ekstraksi cair-cair (LLE) dengan menggunakan metode baku dari Environmental Protectian Agency (EPA) yang dianggap klasik dan metode modern Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) melalui eksperimen sistem batch. Kajian disipasi azoxystrobin dalam tanah dengan melakukan kontrol terhadap suhu dilakukan pada 5, 20, dan 35 oC. Pengaruh cahaya matahari terhadap laju disipasi azoxystrobin dalam tanah dilakukan pada dua kondisi yang berbeda, yaitu pada kondisi terang (terpapar radiasi matahari) dan reaksi gelap (dalam lemari gelap). Laju disipasi di dua karakteristik tanah yang berbeda juga dikaji dalam penelitian ini. Metode ekstraksi QuEChERS menunjukkan performa yang lebih baik dibanding metode EPA. Metode analisis azoxystrobin dengan menggunakan HPLC telah divalidasi dengan nilai rata-rata, akurasi, presisi, sensitivitas, dan linearitas. Batas deteksi (LOD) dan kuantifikasi (LOQ), masing-masing, 0,02 mg/Kg dan 0,05 mg/Kg. Kisaran perolehan kembali dari azoxystrobin dapat diterima (81,7-107,9%). Laju disipasi azoxystrobin dalam tanah pada suhu 35 oC (k = 0,0146/hari, t½ = 47 hari) lebih cepat dibanding pada suhu 20 oC (k = 0,0129/hari, t½ = 54 hari) dan 5 oC (k = 0,0072/hari, t½ = 96 hari). Sementara itu, laju disipasi azoxystrobin di tanah pada kondisi terang (k = 0,2018/hari, t½ = 3,4 hari) lebih cepat dibanding pada kondisi gelap (k = 0,0912/hari, t½ = 7,6 hari). Berkurangnya azoxystrobin di tanah akibat pengaruh suhu dan cahaya matahari berbeda secara signifikan (p < 0,05). Disimpulkan pula, jenis mikroba yang berbeda antara dua karakteristik tanah menjadi penyebab berbedanya laju disipasi azoxystrobin di tanah.

Dissipation studies of azoxystrobin in soil were analyzed by a HPLC. Extractions of the soil were done by liquid-liquid extraction (LLE) with two methods, Environmental Protectian Agency (EPA) method (classical) and Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method (modern) through the experimental batch system. Dissipation of azoxystrobin in soil by controlling the temperature was done at 5, 20, and 35 oC. Influence of solar radiation on dissipation rate of azoxystrobin in soil was studied in two different conditions, in light conditions (exposure to sunlight) and dark reactions (in a dark closet). Azoxystrobin dissipation rate in different characteristic of soil was studied in this study. QuEChERS method showed better performance than the EPA method. Analysis method of azoxystrobin has been validated using HPLC by means, accuracy, precision, sensitivity, and linearity. Limit of detection (LOD) and limit of quantification (LOQ) were 0.02 mg/Kg and 0.05 mg/Kg, respectively. The relative recoveries of the azoxystrobin were acceptable (81.7-107.9%). The dissipation rate of azoxystrobin in soil, under the control of the temperature at 35 oC (0.0146/day, t½ = 47 days) was faster than the temperature at 20 oC (0.0129/day, t½ = 54 days) and at 5 oC (0.0072/day, t½ = 96 days). The dissipation rate of azoxystrobin in light conditions (0.2018/day, t½ = 3.4 days) was faster than in dark conditions (0.0912/day, t½ = 7.6 days). Dissipation of azoxystrobin in soil as influenced by temperature and solar radiation were significantly different (P<0.05). Different type of microorganism in two soils characteristic was assumed to cause differences of dissipation rate of azoxystrobin in soil.

Kata Kunci : azoxystrobin, temperature, solar radiation, extraction, QuEChERS, chromatography