Mass spectrometry coupled with liquid chromatography (LC-MS) is a powerful technique for chemical and pharmaceutical analyses. An initial separation is performed using Ultra-High Performance Liquid Chromatography (UHPLC) to resolve analytes in time. The effluent is then directed into a mass spectrometer to determine the mass spectrum of each component based on the observed mass-to-charge ratio (m/z) for each species. High Resolution Accurate Mass Spectrometry (HRAMS) allows the determination of molecular weight and possible molecular formulae for unknowns, or can provide confident and hyper-specific characterization and quantitation of known species of interest. The extreme specificity and sensitivity of mass spectrometry make it an ideal choice for determining the concentrations and identities of low-level components present in pharmaceuticals and biologics. Tandem mass spectrometry (MS/MS) allows an additional level of specificity to testing, as well as providing structural confirmation or determination of known and unknown species. This technique also has the advantage of requiring very small sample sizes, down to the mg and ml level.
Improved Pharma uses LC-HRAMS(/MS), which is especially useful for:
Characterization:
- Chemical identity and purity of known species in API and drug product by a combination of retention time, exact mass measurement, and product ion distribution.
- Elucidation of unknown species and contaminants at concentrations far below the capabilities of NMR
- Isotopic distribution determination /confirmation of labeled compounds
- Peptide/protein sequence determination/confirmation of peptides and proteins
- Post-translation modification to proteins
- Antibody-Drug Conjugates (ADCs) Drug-Antibody Ratios (DAR)
- Polymer identity, molecular weight distributions (Mw, Mn, MP) and polydispersity (PD)
- Small molecules to large biological molecules characterized on the same platform, sometimes within the same method
Quantitation:
- Femtomolar to Attomolar-level (10-15M to 10-18M) quantitation possible
- Simultaneous quantitation of many components of complex mixtures
- UV-inactive species (no chromophore) can be quantitated
- 104 to 105 dynamic range for quantitation of analytes
Improved Pharma’s LC-MS Instrumentation: Improved Pharma features a SCIEX 6600 TripleTOF quadrupole time-of-flight mass spectrometer (QTOF) coupled to a SCIEX EXION UHPLC liquid chromatography system. The mass spectrometer features a dual APCI and ESI source, along with nanospray capability. An automated calibrant delivery system allows frequent mass calibration and very high mass accuracy. The mass analyzer configuration allows an initial ion selection using a quadrupole mass filter (10-10k Da for a single charge) followed by fragmentation in a collision cell and determination of product ions masses in the TOF. The high resolution of the TOF analyzer allows isotopic resolution up to its mass limit for a singly-charged species. The instrument can be operated in positive and/or negative ion modes. It also offers a unique additional mode of separation based on ion mobility with a SelexION differential mobility. This allows the separation of isobaric / isomeric compounds possessing the same chemical formula and characteristics. While not a replacement for chiral chromatography, the technique can operate on UHPLC timescales and is very useful for specific situations.
The SCIEX EXION UHPLC allows faster separations and superior resolution to traditional HPLC instruments. The instrument can operate at pressures of up to 18 kbar and allows for the exceptional performance of analytical columns with modern, small particle stationary phases.
At Improved Pharma, our LC-MS capabilities allow us to solve a huge range of problems for both small molecule pharmaceuticals up to the largest biologics. Explore our website to learn more about how our expert team can support your next project.
