Amino acid analysis is an analytical testing approach used for the quantification of amino acids and evaluation of related substances in pharmaceutical APIs, excipients, nutraceuticals, dietary supplements, and other applicable products. Testing may support assay, purity, and quality control requirements, depending on the product, applicable specification, and testing objectives.
NJ Labs performs amino acid analysis using validated chromatographic methods, including post-column ninhydrin derivatization for applicable pharmaceutical testing requirements. This approach enables the separation and quantification of amino acids and relevant ninhydrin-positive substances, including ammonium where specified, within a single analytical workflow.
NJ Labs performs amino acid analysis using a bio-inert Titanium UPLC coupled with a closed Pickering PCX post-column derivatization system. This ion-exchange chromatography approach with post-column ninhydrin derivatization is used for applicable Ninhydrin Positive Substances (NPS) and ammonium testing in pharmaceutical amino acid materials and is consistent with the analytical principle described in Ph. Eur. 2.2.56 Method 1. Depending on the applicable monograph and specification, the analysis can provide assay and purity information, including NPS and ammonium results, within a single analytical workflow.
| System Component | Why It Matters for Amino Acid Analysis |
|---|---|
| Bio-inert Titanium UPLC | Titanium construction and PEEK tubing help minimize corrosion and potential metal-related interactions with specialized mobile phases used for amino acid analysis. |
| Pickering Cation-Exchange Lithium-Ion Column | Custom-manufactured by Pickering Labs for free amino acid separation. The lithium-ion column provides selective ion-exchange separation of amino acids prior to post-column derivatization and detection. |
| Closed Pickering PCX Post-Column System | Combines separated analytes with Trione-containing ninhydrin reagent under controlled temperature and flow conditions. The closed system supports consistent reagent delivery and reproducible post-column derivatization. |
| Dual-Wavelength Detection (440 nm / 570 nm) | Detection at 570 nm is used for the colored derivatives of primary amino acids, while 440 nm is used for the response of secondary amino acids such as proline and hydroxyproline. Using both wavelengths supports detection and quantification across different amino acid classes. |
NJ Labs offers amino acid analysis using post-column derivatization for applicable pharmaceutical testing requirements. Additional analytical approaches may be used where appropriate based on the product, applicable monograph, specification, and testing objectives.
| Method | Primary Application | Key Characteristics |
|---|---|---|
| Post-Column Derivatization (NPS Method) | Potency (assay) and purity testing, including NPS and ammonium where applicable, for pharmaceutical amino acid APIs and excipients. | Bio-inert Titanium UPLC with a Pickering cation-exchange lithium-ion column and closed PCX post-column derivatization system. The approach enables chromatographic separation followed by ninhydrin-based detection and quantification. The method is consistent with the analytical principle described in Ph. Eur. 2.2.56 Method 1 and may be applied to relevant pharmacopeial testing requirements. |
| HPLC Amino Acid Analysis | Amino acid content quantification in pharmaceutical and nutraceutical products. | HPLC methods for amino acid analysis may use derivatization and/or chromatographic detection appropriate to the specific analyte and method. Depending on the analytical procedure, separation may be performed using reversed-phase or ion-exchange chromatography with UV or fluorescence detection. |
| LC-MS Amino Acid Analysis | Amino acid identification and quantification in complex matrices, where mass spectrometric detection is appropriate. | Combines liquid chromatography separation with mass spectrometric detection to provide molecular-specific information and support identification and quantification of amino acids. |
| Titration | Amino acid raw material testing where specified by the applicable method or specification. | A classical analytical approach that may be suitable for certain raw materials but generally provides less chromatographic selectivity than separation-based methods. Suitability depends on the analyte, matrix, and applicable specification. |
Titration is used only where appropriate to the applicable raw material, method, or specification and is not a substitute for chromatographic impurity profiling or NPS testing where those tests are required.
NJ Labs has established testing capability for the following amino acids and selected related compounds. Specific salt, hydrate, or other physical forms may be evaluated based on method suitability and testing requirements. Contact NJ Labs to discuss any amino acid or related compound not listed.
NJ Labs also analyzes Glucosamine and Naringin on the same analytical platform. These compounds are not amino acids; however, testing may be available for applicable supplement and botanical matrices.
NJ Labs provides amino acid analysis services for pharmaceutical, nutraceutical, and dietary supplement manufacturers. Contact NJ Labs to discuss your analyte, product or material, applicable specification, and testing requirements.
Providing the amino acid and physical form, applicable monograph or specification, intended market, and desired timeline can help NJ Labs determine the appropriate analytical approach and project requirements. Contact NJ Labs today to discuss your amino acid testing needs. All project discussions are handled confidentially.
Amino acid analysis identifies, separates, and quantifies individual amino acids in a sample. In pharmaceutical quality control, testing may support assay and purity evaluation, including the determination of related substances and ammonium where applicable. Analytical approaches may include post-column ninhydrin derivatization, HPLC, LC-MS, or titration, depending on the analyte, matrix, applicable method, and specification.
