The 4000 QTRAP LC/MS/MS System is our premier hybrid triple quadrupole/linear ion trap mass spectrometer. Ideal for drug discovery and development, metabolite identification, contaminant testing, and proteomic applications including post-translationally modified protein discovery, protein identification, and biomarker validation. Enable high-sensitivity, full-scan MS, MS/MS, and MS3 spectra with high selectivity from true triple quadrupole precursor ion (PI) and neutral loss (NL) scans. Perform multiple reaction monitoring (MRM) scans for quantitation using high-sensitivity triple quadrupole instrumentation. Identify, characterize, and quantitate metabolites more quickly and easily. Identify and sequence post-translationally modified (PTM) peptides automatically in a single LC/MS/MS run. Facilitate hypothesis-driven biomarker discovery and validation.