Analisis Residu Klorpirifos pada Sawi Hijau (Brassica Rapa Var. Parachinensis L.) Terhadap Parameter Waktu Retensi Metode Kromatografi Gas

The purposed of the research is analyzed the chlorpyrifos in green mustard of the retention time parameter with gas chromatography. The green mustard was collected of ready harvest condition with sample collecting point on diagonal form in the farm. As standard was used chylorpyrifos 99,9%. The research was begin with make the standard at 0,05 ppm dan sample extraction was made duplo. Standard solution and sample was injected by rolling over in the gas chromatography with column of fused silica Rtx-1 (crossbond dimetyl polisiloxan length 30 meter, inner diameter 0,25 mm and the partikel diameter of stationary phase fase diam 0.25 um), electron capture detector, carrier gas nitrogen with flow rate 1,61 mL/min, conditioned at column temperatur 250 C, injector temperature 280 C and detector temperature 300 C and operating time for 15 minutes. The parameter was used is time retention (tR). The result showed at chromatogram in sample I and II, time retention was obtained similar with standard solution time retention although showed time retention difference above required limit while in sample I and II having the characteistic retention time of standard solution. The retention time based on gas chromatography method can be knew the concentration of chlorpyrifos as 1,0024 mg/kg but it still on tolerance threshold the maximum residue limits (MRL) is 0,1 mg/k