3. A series of calibration standards of metathione (a pesticide) containing internal standard was analyzed on a 30 m GC column. The concentration range of the standards was 1.00 to 100.00 ppm (m/V). The line formula y = 0.564x + 0.235 was obtained. Pulped tomatoes (100g) were made homogeneous and from this 1.00g sample was extracted three times with 20.00 mL ethyl acetate. The three extracts were combined and diluted to 100.00 mL and the same volume as used for the standards were analyzed by GC. The following results were obtained.
able[[,Retention time (min),Peak width (sec),Peak area],[Compound 1 (Unretained),1.7,,10765],[Compound 2 (Internal std),8.4,6.1,564],[Compound 3 (Analyte),13.3,7.3,1923],[Compound 4,15.4,8.6,176],[Compound 5,15.6,9.5,165]]
3.1 Calculate the metathione content of the tomatoes in ppm (m/m).
(7) = 0.563 ppm (m/V)
4. A technician must analyze tomato paste for the presence of atrazine and captafol, two active ingredients present in pesticide formulations. Stock solutions of the authentic reference materials were prepared by dissolving 5.00 mg of each and diluting to 10.00 mL with chloroform. Calibration standards were subsequently prepared in chloroform by accurately diluting 20.0; 100.0; 200.0 and 500.0 μL to volume in 10 mL volumetric flasks, following the addition of internal standard. An accurately weighed mass, 20.2158 g of tomato paste was extracted three times with 20 mL of ethyl acetate. The extracts were combined and dried. The residue was redissolved in dichloromethane, internal standard was added and diluted to 20.00 mL. Results:
able[[,Peak area Atrazine,Peak area Captafol,Peak area (IS)],[Std 1,42,36,118],[Std 2,210,185,120],[Std 3,413,354,116],[Std 4,2224,1907,125],[Sample,264,168,112]]
Calculate the concentration of the pesticides in the tomato paste expressed as ppm (m/m) with the aid of a graph. Please explain all of them respectfully thank you.
