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📅 Last Updated: October 24, 2026
The difference between High-Performance Liquid Chromatography (HPLC) and Liquid Chromatography–Mass Spectrometry (LCMS) with schematic diagram comes down to what each technique does. HPLC separates and analyses compounds in a mixture. LC-Mass Spectrometry (MS) adds mass spectrometry to identify and quantify them. LC-MS is more sensitive but needs trained analysts. HPLC with Ultraviolet (UV) detection can use volatile and non-volatile buffers, while LC-MS needs volatile buffers.
One practical difference between HPLC and LCMS, shown in the schematic diagram below, is the buffer you can use. HPLC with UV detection can use volatile and non-volatile buffers. LCMS needs volatile buffers, because non-volatile salts such as phosphate precipitate in the ion source and reduce sensitivity.
Common Difference between HPLC and LCMS/HPLC-MS with schematic diagram
This section explains what HPLC, LC-MS and HPLC-MS are and how they relate to each other.
HPLC full form is High-Performance Liquid Chromatography. HPLC is a liquid chromatography technique that separates and analyses compounds in a mixture based on their physical and chemical properties. It is a precise method, widely used in pharmaceuticals, and it can detect even trace amounts of a substance. United States Pharmacopeia (USP) <621> Chromatography sets the system suitability and allowable adjustment requirements for HPLC methods used in pharmaceutical testing. You can read more in our post on system suitability in HPLC.
LC-MS stands for Liquid Chromatography-Mass Spectrometry. LC-MS is a technique that combines liquid chromatography (LC) separation with mass spectrometry (MS) identification and quantification. Mass spectrometry measures the mass-to-charge ratio (m/z) of charged particles (ions). LC-MS works for different types of compounds in complex mixtures, including:
- small molecules
- proteins
- peptides
It is highly sensitive and finds low levels of substances in a sample. Under International Council for Harmonisation (ICH) Q2(R2), an HPLC or LC-MS assay used for pharmaceutical release testing must be validated. This covers parameters such as specificity, accuracy, precision and detection limit.
HPLC-MS: HPLC-MS is commonly called LC-MS. Combining both techniques adds specificity, sensitivity and identification, because HPLC separates the components and the mass spectrometer acts as a highly specific detector. LC-MS is widely used for a variety of compounds.
Difference between HPLC and LCMS (comparison table)
The table below shows the HPLC and LC-MS setups side by side.
| HPLC | LCMS |
|---|---|
| Full Name: High-Performance Liquid chromatography (or) High-Pressure Liquid chromatography. | Full Name: Liquid Chromatography Coupled with Mass Spectrometry. |
| Buffers: Non-volatile and Volatile buffers will be used Examples: Phosphate buffers, Citrate buffers, Trifluoroacetic acid, Ammonium Acetate, Ammonium formate (NH4HCO2), Formic acid, Acetic acid, and Bicarbonate buffers. | Buffers, Only volatile buffers will be used Examples: Ammonium acetate, Ammonium formate (NH4HCO2), Formic acid, Acetic acid, and Ammonium bicarbonate buffers -Phosphate buffers (Non-volatile buffers) will not be used. |
| It helps in the separation and identification of a mixture of compounds through a PDA or UV detector. | LC helps in the separation of a mixture of compounds whereas Mass Spectrometry helps in the identification of compounds. |
| Low sensitivity and specificity and will not give any molecular structure information. | It can provide high sensitivity, specificity, and molecular structural information for the qualitative assay of drugs and their metabolites. |
| Sample Processing: Mostly Clean or Aqueous sample -No sample extraction required. | Sample Processing: Mostlybiological sample -Sample extraction is required to extract the compound to the solution which can be injected into the LCMS. |
| Detection: The detection of a compound is based on the wavelength. | Detection: The detection of a compound is based on m/z (mass/charge ratio). |
| Detector: PDA or UV detector. | Detector: CEM ( Channel Electro Multiplier). |
| Uses: It is used for identifying, quantifying, and purifying the individual components of the mixture. | Uses: It is used for the separation, identification, and quantification of both unknown and known compounds as well as to elucidate the structure and chemical properties of different molecules. |
| Analysis: It is used to analyze finished drug products and their ingredients quantitatively and qualitatively. | Analysis: It is used to analyze biochemical, organic, and inorganic compounds quantitatively and qualitatively. |
Advantage of LCMS over HPLC
LC-MS is more sensitive, selective and accurate than HPLC, and it gives molecular mass and structural information for identification. It is not inherently faster, because the column, mobile phase and gradient set the run time. It needs trained analysts because it is harder to operate. Schedule M and World Health Organization (WHO) Good Manufacturing Practice (GMP) require analysts to be qualified and trained for the instruments they operate, which applies to LC-MS systems. Choose the technique by the job:
- Use HPLC for routine separation and assay work.
- Use LC-MS when identification or trace-level detection is needed.
Frequently Asked Questions
Ans: LC-MS technique is often considered to be a more accurate, sensitive, and specific method than HPLC because it combines the separation capabilities of LC with the identification and quantification capabilities of MS. In summary, LC-MS instruments are more effective than HPLC.
HPLC stands for High-Performance Liquid Chromatography. It is a liquid chromatography technique that splits a mixture into its compounds and analyses them based on their physical and chemical properties. It is a precise method, widely used in pharmaceuticals, and it can detect even trace amounts of a substance.
Yes. LC-MS is more sensitive, selective and accurate than HPLC. It is not inherently faster, because the liquid chromatography conditions set the run time. It is highly sensitive and finds low levels of substances in a sample. The trade-off is that it is harder to operate, so a trained analyst must run it.
LC-MS is not easy to operate, so the analyst needs training on the instrument. Schedule M and WHO GMP require analysts to be qualified and trained for the instruments they operate. This applies to LC-MS systems as much as to any other laboratory equipment.
HPLC with UV detection can use both volatile buffers (such as formic acid, acetic acid, ammonium formate and ammonium acetate) and non-volatile buffers such as phosphate. LC-MS needs volatile buffers, because non-volatile salts precipitate in the ion source and reduce sensitivity. The limit comes from the MS detector, not from HPLC itself. It is one practical difference between HPLC-UV and LC-MS, and it is the first point to keep in mind when you move a method from HPLC to LC-MS.
HPLC-MS is the combination of HPLC and mass spectrometry, and it is commonly called LC-MS. Combining both techniques adds specificity, sensitivity and identification, because HPLC separates the components and the mass spectrometer acts as a highly specific detector. LC-MS is widely used for a variety of compounds, including small molecules, proteins and peptides in complex mixtures.
References
- USP <621>, United States Pharmacopeia (USP–NF)
- ICH Q2(R2), International Council for Harmonisation (ICH)
- Schedule M, CDSCO, Drugs Rules, 1945
- WHO GMP, World Health Organization
Pankaj Sharma — Quality Control Specialist
Pankaj Sharma is a pharmaceutical QC professional who reviews our technical content for GMP accuracy, laboratory practices, and regulatory relevance.