Understanding Laboratory Analysis
Understanding Laboratory Analysis
This page provides general educational information about analytical techniques commonly referenced within laboratory product specifications. It is intended for scientific reference only and does not constitute a Certificate of Analysis (COA) for any individual product or batch.
At Absolute Peptides UK, technical specifications are provided to help explain the scientific characteristics of laboratory research materials. The information below outlines commonly used analytical techniques and scientific terminology referenced throughout our product specifications.
High Performance Liquid Chromatography (HPLC)
High Performance Liquid Chromatography (HPLC) is one of the most widely used analytical techniques for assessing the relative purity of peptide materials.
During analysis, a dissolved sample passes through a specialised chromatography column where individual components separate according to their chemical properties. This allows the primary peptide to be distinguished from impurities, synthesis by-products or degradation products that may be present within the sample.
Purity is typically expressed as a percentage based on the chromatographic profile obtained under defined analytical conditions. For example:
- 99.5% HPLC Purity indicates that approximately 99.5% of the analysed material corresponds to the primary chromatographic peak under the conditions used for analysis.
HPLC is commonly used to assess sample purity but does not, by itself, confirm molecular identity.
Liquid Chromatography-Mass Spectrometry (LC-MS)
Liquid Chromatography-Mass Spectrometry (LC-MS) combines chromatographic separation with highly accurate molecular mass analysis.
Following chromatographic separation, the sample enters a mass spectrometer where molecules are ionised and their mass-to-charge ratio (m/z) is measured. Using this information, the instrument calculates the molecular mass of the compound with a high degree of accuracy.
LC-MS is widely used to help confirm that the measured molecular mass corresponds with the expected molecular mass of the intended peptide, providing additional confidence in compound identity.
In simple terms:
- HPLC helps assess how pure a sample is.
- LC-MS helps confirm the identity of the molecule being analysed.
These analytical techniques are frequently used together during peptide characterisation.
Karl Fischer Moisture Analysis
Residual moisture is commonly measured using Karl Fischer titration, an internationally recognised analytical technique specifically developed to determine water content.
Lyophilised peptide powders naturally retain very small amounts of residual moisture following the freeze drying process. Measuring this residual water helps characterise the material and may influence storage characteristics and long-term stability.
Residual moisture is typically reported as a percentage of the total sample weight.
Molecular Weight
Molecular weight describes the mass of a single molecule and is typically expressed in grams per mole (g/mol).
Every peptide possesses a unique molecular weight determined by its amino acid sequence and chemical structure.
For example:
- Retatrutide – 4671.41 g/mol
- Tirzepatide – 4813.45 g/mol
- MOTS-c – 2174.53 g/mol
Analytical techniques such as LC-MS are commonly used to verify that the measured molecular mass corresponds with the expected theoretical value.
Molecular Formula
A molecular formula identifies the number and type of atoms present within a molecule.
For example:
C₂₂₅H₃₄₈N₄₈O₆₈
indicates the precise numbers of carbon, hydrogen, nitrogen and oxygen atoms present within that particular peptide.
Every peptide has its own unique molecular formula based upon its chemical structure. Molecular formulas form part of the chemical identity of a compound and are commonly referenced alongside molecular weight and CAS numbers within technical documentation.
CAS Numbers
A CAS (Chemical Abstracts Service) Registry Number is a globally recognised numerical identifier assigned to a specific chemical substance.
CAS numbers provide a standardised method of identifying compounds across scientific publications, laboratories and chemical suppliers.
Each CAS number uniquely identifies one specific chemical substance regardless of its trade name, manufacturer or supplier.
A CAS number identifies a chemical substance but does not indicate purity, quality or intended use.
Lyophilised Powder
Most peptide research materials are supplied as a lyophilised powder.
Lyophilisation, also known as freeze drying, removes water from a material under carefully controlled low temperature and vacuum conditions. This process is commonly used to support the long term storage of many peptide research materials while preserving their physical characteristics.
Lyophilised materials are commonly stored under refrigerated or frozen conditions until required for laboratory research.
Certificates of Analysis (COAs)
A Certificate of Analysis (COA) is a batch specific analytical document that summarises the results of laboratory testing for an individual production batch.
Depending on the material and testing performed, a COA may include information such as:
- Batch or lot number
- Date of analysis
- HPLC purity
- LC-MS identity confirmation
- Residual moisture
- Appearance
- Storage recommendations
Product specification pages provide general scientific reference information. Where available, batch specific COAs provide analytical results relating to an individual production batch.
Product Specifications
Technical specifications published by Absolute Peptides UK are intended solely as scientific reference information.
Where analytical methods such as HPLC, LC-MS or Karl Fischer moisture analysis are referenced, they describe commonly used laboratory techniques for characterising peptide materials.
Product specification summaries are provided for informational purposes and should not be interpreted as batch-specific Certificates of Analysis (COAs) unless expressly stated. Where applicable, batch specific analytical documentation should be consulted separately.
Research Use Only
All products supplied by Absolute Peptides UK are intended exclusively for legitimate laboratory research and analytical purposes.
They are not intended for human or veterinary use, therapeutic use, diagnostic use, medicinal use, cosmetic use or as food or dietary supplements.
Please refer to our Research Use Disclaimer and Terms & Conditions for further information.