In analytical chemistry, particularly in fields like biochemistry, food science, and clinical diagnostics, accurate amino acid analysis is essential. The use of internal standards is a well-established method to compensate for variations in sample preparation and analytical processes, ensuring the reliability of quantitative results. DL-Norvaline (CAS 760-78-1) is frequently employed as an amino acid internal standard due to its stable nature and distinct chromatographic properties. For laboratories and research institutions, procuring high-quality DL-Norvaline as a standard is paramount for achieving precise analytical outcomes. This guide focuses on understanding its role and how to buy reliable standards.

The Importance of Internal Standards in Amino Acid Analysis

Amino acid analysis typically involves complex sample preparation, including hydrolysis, derivatization, and chromatographic separation. Each of these steps can introduce variability that might affect the accuracy of quantification. An internal standard, such as DL-Norvaline, is a compound that is added to both calibration standards and unknown samples at a known concentration. By measuring the ratio of the analyte's signal to the internal standard's signal, analysts can correct for variations in sample injection volume, detector response, and other process-related fluctuations. DL-Norvaline, being a non-proteinogenic amino acid, is ideal as it is typically absent in biological samples, thus minimizing interference.

Quality Specifications for DL-Norvaline Standards

When purchasing DL-Norvaline specifically for use as an analytical standard, quality is of utmost importance. While general DL-Norvaline might have a standard purity of 98%, analytical standards often require even higher purity and tighter specifications. Suppliers of analytical standards should provide a comprehensive Certificate of Analysis (CoA) that details the purity, identity confirmation (e.g., via NMR or MS), and potentially even traceability to national metrology institutes. The physical form, often a precisely weighed lyophilized powder, and its reconstitution instructions are also critical for ease of use and accuracy. Buyers should look for suppliers that explicitly market their products as 'Amino Acid Internal Standards' or 'Reference Standards.'.

Finding Reliable Suppliers and Purchasing DL-Norvaline Standards

Procuring reliable analytical standards requires careful selection of suppliers. While many chemical manufacturers offer DL-Norvaline, not all are specialized in producing high-purity analytical standards. It is advisable to seek out companies known for their expertise in supplying laboratory reagents and analytical standards. These suppliers often have dedicated quality control departments and rigorous testing protocols for their standard products. Companies may also look to purchase DL-Norvaline from established global brands known for their commitment to analytical accuracy, or from trusted regional suppliers, including those in China who specialize in fine chemicals and analytical reagents.

Factors to Consider When Buying

When you decide to buy DL-Norvaline for use as an internal standard, consider the packaging size – often smaller quantities are sufficient for laboratory use. Investigate the supplier's shipping and storage recommendations, as standards often require specific conditions (e.g., refrigeration) to maintain their integrity. Compare pricing, but always prioritize a supplier with a proven track record for producing accurate and reliable analytical standards. For laboratories and research institutions, investing in high-quality DL-Norvaline standards is an investment in the accuracy and credibility of their analytical work.