Sample Preparation: Supelco C18 Solid phase Extraction.
Std Prep: pipet 25.0, 50.0, 100.0, 150.0, 200.0 ul from EPA stock STD solution ( 10 ug/ ml) into 5 ml VF, then bring to volume with acetone to obtain a serial of Conc. 50.0, 100.0, 200.0, 300.0, 400.0 ug/L STD solution.
Column: DB - 5MS ( 30 m × 0.25 mm id × 0125μm)
Initial Temp: 120℃ hold 2 min, ramp to 240℃ at 15℃/min, Hold 5 min, ramp to 260℃ at 10℃/min, hold 2 min
Carrier gas: He
Flow rate: 1 ml/min
Injection Volume: 1 ul
Split-Splitless: Splitless at 1 min, Splitl ratio: 1∶20
Mass: EI ion sources ( 70 v) ;Ion Sources Temp: 240℃;
Connect Temp: 260℃;
Solvent delay: 310 min;
Full Scan Range M/Z:40 ～ 450 amu。
Selecting Ion Monitor (SIM) for quantitative analysis ( Please see the table)
Chlorothalonil: 139, 141, 250, Molecular Ion: 139
Dicofol : 264, 266, 268, Molecular Ion: 266
http://en.wikipedia.org/wiki/Chlorothalonil
Pesticides Molecular Ion ( M/Z) Selecting Ion Monitor ( M/Z) Retention Time
Chlorothalonil 268 264, 266, 268 10.5
Quintozene 249 214, 247, 249 8.5
Dicofol (DDT) 139 141, 250 139 14.2
