Combining ultra-high performance liquid chromatography with mass spectrometry (UHPLC-MS) builds a potent tool in analytical chemistry. However, it also demands the use of exceptionally pure solvents in mobile phase solutions to facilitate trace analysis.
By using solvents designed for UHPLC-MS mobile phases, researchers can achieve minimal metal ion content, ultra-low mass noise in both positive and negative mode ionization and an extremely low UHPLC-UV response when employed with photodiode array detection.
This whitepaper highlights how the latest advancements in UHPLC-MS grade solvents can accelerate complex sample analysis while maintaining accuracy.
Download this whitepaper to discover:
- How the latest UHPLC-MS grade solvents enhance analytical precision for trace-level analysis
- Practical applications and case studies showcasing the power of UHPLC-MS
- The critical role of ultra-pure solvents in UHPLC-MS applications to ensure minimal interference and optimal sensitivity
UHPLC-MS grade solvents for trace level analysis and research methods and assays Chemicals White paper | 0230801 Keywords UHPLC-MS, UHPLC UV, grade solvents, ultra-pure solvents, trace level analysis, research methods, research assays, acetonitrile, methanol, water. Authors Subhra Bhattacharya, Deva H. Puranam, Stephen C. Roemer; Thermo Fisher Scientific, One Reagent Lane, Fair Lawn, NJ, USA Summary Thermo Scientific™ manufactures the solvent grade, UHPLC-MS for use in mobile phases targeting trace level analysis and research studies using UHPLC-MS technology. These ultra-pure solvents provide a very low mass noise level in both positive and negative mode ionization, minimal metal ion content, and very low UHPLC UV response using photo diode array detection. These high purity solvents are specifically qualified for UHPLC-MS and offered in acetonitrile, methanol, and water. Chemicals Introduction Ultra-high performance liquid chromatography (UHPLC) is associated with submicron particle size column and high pressure flow resulting in increased resolution and sensitivity for complex sample mixtures and increased speed of analysis. Mass spectrometry (MS) enables the detection and identification of analytes at the parts per trillion level. UHPLC coupled with MS (UHPLC-MS) is a powerful tool in analytical chemistry that requires mobile phase solutions prepared with exceptionally pure solvents permitting trace analysis. UHPLC-MS solvent grade for mobile phases targeting UHPLCMS show a very low mass noise level in both positive and negative mode ionization, minimal metal ion content, and very low UHPLC-UV response using photodiode array detection.Material and methods Mobile phase Acetonitrile (ACN), methanol, and water were evaluated; all three solvents are UHPLC-MS grade. Instrument Thermo Scientific™ Accela™ UHPLC system comprised of an autosampler, photodiode array detector, and attached to an LTQ-XL mass spectrometer equipped with an electro-spray ionization interface. Column Thermo Scientific™ Hypersil Gold™ column (50 mm x 2.1 mm, 1.9 μm), Cat. no. 26102-052130. Standards Propazine (SPEX CertiPrep, S-3170,1000 μg/mL) as the positive mode standard and chloramphenicol (SPEX CertiPrep, S-4032, 1000 μg/mL) as negative mode standard. These standards provided adequate ionization without any additive applied to the mobile phase. Operation The mass spectrometer was operated in full scan ESI-MS from 100 to 1500 amu. The collision induced dissociation (CID) mass spectra were obtained with helium as the collision gas after isolation of the particular precursor ion. Other parameters including gas flow and capillary voltage were adjusted as required. HPLC gradient • 0 – 0.5 min: 90% water, 10% ACN • 0.5 min – 2.0 min: 0% water, 100% ACN • 2 min – 5 min: 100% ACN • Post run 5.1 min – 10 min: 90% water, 10% ACN Flow rate 0.6 mL/min for water/ACN, 0.5 mL/min for water/methanol Injection volume 5 μL Propazine Chloramphenicol Chemical folmula: CH16 CIN Exact mass: 229.11 Molecular weight: 229.71 (M+H)• = 230.11 Chemical folmula: C11 H12 CI€N€O Exact mass: 322.01 Molecular weight: 323.13 (M-H)- = 321.01 Results • Mobile phase solvent purity was evaluated by linking UHPLCMS sensitivity to trace analysis of positive and negative mode standards (Figures 1–10). • Propazine was used as positive mode standard (Figures 3–6) and chloramphenicol as negative mode standard (Figures 7–10) in order to assess interfering baseline peaks in both full scan ESIMS and CID generated product ions. Figure 1. Blank gradient of water/ACN – PDA, UV and TIC Figure 2. Blank gradient of water/methanol – PDA, UV and TIC 2Water/ACNWater/methanol Figure 3. Serial dilution of propazine – EIC of m/z 230 Water/methanol Water/ACN Figure 4. Mass spectra of m/z 230 propazine peak (250 pg) Figure 5. MS/MS of propazine from serial dilution Water/ACN Water/methanol Figure 6. MS/MS spectra of propazine in two different solvent systems Figure 7. Serial dilution of chloramphenicol Figure 8. Mass spectra of chloramphenicol in water/ACN and water/methanol Water/methanol Water/ACN Water/A
