Selected reaction monitoring SRM confirmation

The instrument scan mode called selected reaction monitoring (SRM) is generally used for quantitative applications. SRM is similar to selected ion monitoring (SIM) in single quadrupole MS. The difference is that a product ion from the decomposition reaction in the collision cell is measured instead of a single ion formed in the 

At Bayer CropScience, the use of a stable isotope IS has become common practice to eliminate the effects of matrix suppression on instrument signals. The stable isotopes are synthesized by deuterium exchange reactions on authentic native standards or the 

The determination of the LQD and LQQ is an important aspect of any method used for water analysis. A review article by Keith outlines many of the issues concerning the determination of method detection limits. In general, the determination of the 

Two examples will be presented as an example of groundwater analyses at Bayer CropScience. Both analyses were carried out using DAI with the aid of a stable isotope IS. Attempts at conventional SEP extractions presented special problems because of adsorption of metabolites on the SEP media or oxidative instability during extraction. A brief description of the procedures is outlined below. 

Instrument type Specificity/sensitivity Sample preparation time Data quality Cost effectiveness 

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