2015 Volume 6 Issue 1 Pages 3-10
In the CCLD method, calibration curves necessary for identification and quantification of chemicals and the information on the retention time are entered into the database. It is possible to efficiently analyze various types of chemicals without measuring the appropriate standards of the target chemicals.Since the CCLD method uses calibration curves registered in the database to calculate quantity, it is currently necessary to correct the mass spectrometer using the DFTPP turning method of EPA625 (hereinafter referred to as“D method”), and spectral patterns meet the standard of the relative strength ratio prescribed by EPA625.However, to satisfy the standard of the prescribed relative strength ratio, one cannot take full advantage of the secondary electron multiplier (SEM) with conversion dynode (CD), which aims to improve the sensitivity of higher-mass analyses. It was necessary to disable CD and lower the sensitivity of the higher-mass analyses.Therefore, we investigated a way to apply the CCLD method with the GC/MS method that has been corrected with the enabled CD (hereinafter referred to as “A method”) with the aim of improving the sensitivity of the CCLD method.We developed a conversion equation to correct the relative strength ratio of mass spectrometer obtained from the A method to the prescribed relative strength ratio, and converted the internal standard calibration curve registered in the CCLD method database.Pesticide standard was measured, and quantified by the converted calibration curve. For 37 out of 46 pesticides,measured values showed an agreement of 0.8.1.5 times between the A method and the conventional CCLD method,indicating the effective functioning of the developed conversion equation.These results indicate that this method is effective in increasing the sensitivity of the CCLD method.