Filters/filtering high-resolution mass spectrometry

Detection and characterization of metabolites in biological matrices using mass defect filtering of liquid chromatography/high resolution mass spectrometry data. Drug Metab. Dispos. 2006, 34, 1722. 

Zhu, M., Ma, L., Zhang, H., and Humphreys, W. G. (2007). Detection and structural characterization of glutathione-trapped reactive metabolites using hquid chromatography-high-resolution mass spectrometry and mass defect filtering. Anal. Chem. 79 8333-8341. 

The quantitative reliability of inductively coupled plasma high-resolution mass spectrometry for phosphorus determinations was judged by comparing it to the standard total filterable phosphorus method (Gooper et al., 1999). That method includes a persulphate oxidation step to convert all forms of phosphorus to phosphate, which is then suitable for the molybdenum blue reaction. Using the same set of standards, calibration curves for both methods were developed over a range of 0-200 pg P/1. Fig-... 

Zhang H, Zhang D, Ray K, Zhu M. Mass defect filter technique and its applications to drug metabolite identification by high-resolution mass spectrometry. J Mass Spectrom 2009b 44 999-1016. 

Many applications of mass spectrometry do not require high resolution. Thus, other types of smaller, less expensive and lower performance mass spectrometers have been developed. Quadrupole mass filters that use an electric field to separate ions are in this category. These devices are used as mass detectors (GC/MS, LC/MS and ICP/MS) and in a variety of industrial processes for gas and residual gas analyses. 

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