Question

A researcher was attempting to quantify the amount of dichlorodiphenyltrichloroethane (DDT) in spinach using gas chromatography mass spectrometry (GCMS). First attempts using external calibration proved difficult, as reproducibility and external standard agreement were poor. To overcome these problems, the researcher used the internal standard calibration method with chloroform as the internal standard. To begin, the researcher analyzed a sample containing 6.58 mg/L DDT standard and 2.82 mg/L chloroform as the internal standard, which produced peak areas of 3713 and 10899 for the DDT and chloroform, respectively. Determine the response factor ( F ).

Answer 1

Answer:

Determine the response factor ( F ) = 0.146

Step-by-step explanation:

Recalling from Response factor;

• Ax/Cx = F x As/Cs

• where Ax = peak area of analyzed (DDT) = 3713

• As = peak area of standard = 10899

• Cx = concentration of analyzed = 6.58 mg/L

• Cs = concentration of standard chloroform = 2.82 mg/L

• From the equation; F = Ax/As x Cs/Cx

• F = 0.146