Chemicals for LC-MS Biopharmaceutical Applications

LC-MS techniques, which couple liquid chromatography (LC) with mass spectrometry (MS), have increasingly become the method of choice for characterizing biopharmaceutical drugs. Mobile phase solvents and reagents must have low organic impurities to reduce interference with detection by electrospray (ESI) MS.

Analytical Methods

Biopharmaceutical drugs are therapeutic proteins with far more complex structures than small-molecule drugs. At the structural level, protein post-translational modifications (PTMs), which can arise at different stages of manufacturing and storage, can impact drug efficacy and safety. PTMs are therefore classified as critical quality attributes (CQA) and must be monitored and controlled.

LC-MS is used to understand the structure of protein-based drugs, including:

  • Amino acid sequencing for peptides and proteins
  • Profiles of host cell proteins (HCPs) and other process-related impurities
  • Disulfide bond mapping
  • N-glycan profiles of monoclonal antibodies (mAbs)
  • Oligonucleotide sequencing

The combined power of LC separation and the sensitivity and specificity of MS detection makes LC-MS the best choice for mapping peptides to detect multiple PTMs, also called the multi-attribute method (MAM) workflow. Critical to the MAM workflow is the separation of various peptides from the digested therapeutic protein. This is typically achieved using a long LC gradient of water and acetonitrile, with formic acid added as a modifier. (See Figure 1.)

Quantitative determination of mitragynine and 7-hydroxymitragynine as two major psychoactive components of kratom use in human urine by UHPLC-MS/MS for forensic toxicology

Figure 1: Typical LC gradient in a MAM workflow for the separation of NIST mAb peptides with a binary mobile phase: B: 0.1% formic acid in acetonitrile (Cat. No. LS120).

High-Purity Solvents and Reagents

Fisher Chemical Optima grade LC-MS solvents meet your purity needs for LC-MS analysis. Convenient, ready-to-use LC-MS blends are precisely mixed for lot-to-lot consistency and are quality tested using LC-MS. Thermo Scientific UHPLC-MS grade solvents meet even more stringent specifications for your most-demanding analyses. Both LC-MS and UHPLC-MS grade solvents and blends are tested to confirm low organic impurity levels to minimize interference and ion suppression.

These high-purity LC-MS reagents also have extremely low metal impurity levels. Trace metal impurities can cause poor peak shape, peak tailing, and diminished recovery when metal-ion mediated adsorption occurs with the column media. Sodium (Na+), potassium (K+), and other alkali metal ions are electrostatically attracted to the negative charges of carboxyl group of C-terminal amino acids in peptides and proteins or the polyanionic backbone of oligonucleotides. The Naand Kadducts decrease overall sensitivity and compromise peptide identification.

All Thermo Scientific LC-MS grade chemicals strictly control trace metal contamination during production, which is confirmed with ICP-MS testing. Table 1 displays a comparison of impurities in pre-blended LC-MS grade water (with 0.1% formic acid) among four competitive brands.

Purity grades for every LC-MS application are available through the Fisher Scientific channel.

Table 1. Metal Ion Levels (ppb) in LC-MS Grade Water with 0.1% FA from Four Suppliers

Metal IonCat. No. LS118Competitor MCompetitor HCompetitor J

Solvents and Blends

GradeDescriptionPackagingQuantityCat. No.

Optima LC-MS
AcetonitrileAmber Glass Bottles500 mL, 1 L, 2.5 L, 4 LA955
MethanolAmber Glass Bottles500 mL, 1 L, 2.5 L, 4 LA456
WaterAmber Glass Bottles500 mL, 1 L, 2.5 L, 4 LW6
2-PropanolAmber Glass Bottles500 mL, 1 L, 2.5 L, 4 LA461

AcetonitrileClear Glass Bottles1 LA956-1
MethanolClear Glass Bottles1 LA458-1
WaterClear Glass Bottles1 LW8-1

Optima LC-MS Blends
Acetonitrile with 0.1% FAAmber Glass Bottles500 mL, 1 L, 2.5 L, 4 LLS120
Acetonitrile with 20% Water and 0.1% FAAmber Glass Bottles500 mLLS122-500
Acetonitrile with 0.1% TFAAmber Glass Bottles500 mL, 1 L, 2.5 L, 4 LLS121
Acetonitrile with 0.05% TFAAmber Glass Bottles4 LLS1174
Water with 0.1% FAAmber Glass Bottles500 mL, 1 L, 2.5 L, 4 LLS118
Water with 0.1% TFAAmber Glass Bottles500 mL, 1 L, 2.5 L, 4 LLS119
Water with 0.05% TFAAmber Glass Bottles4 LLS115-4

Optima LC-MS Additives

Formic Acid
Poly Bottles50 mLA117-50
Ampules0.5, 1, 2, 10 × 1 mLA117

Acetic Acid
Poly Bottles50 mLA113-50
Ampules0.5, 1, 2, 10 × 1 mLA113

Trifluoroacetic Acid
Amber Glass Bottles50 mLA116-50
Ampules0.5, 1, 2, 10 × 1 mLA116
Ammonium AcetateGlass Bottles50 gA114-50
Ammonium FormateGlass Bottles50 gA115-50

Installation Kit

DescriptionCat. No.
UHPLC-MS Reagent Installation Kit for New LC/MS Systems, Includes:

  • • Acetonitrile, 1 L (Cat. No. A956-1)
  • • Methanol, 2 × 1 L (Cat. No. A458-1)
  • • Water, 2 × 1 L (Cat. No. W8-1)
  • • Thermo Scientific ChromaCare Instrument Flush Solution, 1 L (Cat. No. T111101000); 25% Each of Acetonitrile, Methanol, Water, and 2-Propanol

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