title: Comparison of polarimetry and crown ether-based HPLC chiral stationary phase method to determine (L)-amino acid optical purity.
abstract: Although various pharmacopoeias provide titration methods to assay (L)-amino acid content, none of these methods distinguish between (L)- and (D)-amino acids and do not consider the presence of enantiomeric impurities. Consequently, these methods are limited in scope to describe the relationship between content and specific rotation, [α]. In this study, the US Pharmacopoeia method was compared with the crown ether-based high performance liquid chromatographic (HPLC) chiral stationary phase (CSP) method to determine (L)-amino acid content and specific rotation. The (L)-amino acid content specified by the US Pharmacopoeia method was not consistent with the specific rotation in the presence of enantiomeric impurities, whereas the HPLC-CSP method was very effective for determining the (L)-amino acid content and the optical purity. The other advantage is that the HPLC-CSP method requires amino acid samples of quite low concentration (as low as 1 μg/mL), whereas the pharmacopoeia method requires higher concentrations (20-110 mg/mL).
authors.affiliation: Division of High Technology Materials Research, Busan Center, Korea Basic Science Institute (KBSI), Busan 618-230, Republic of Korea.
authors.forename: Mee Sung
authors.initials: MS
authors.lastname: Lee
authors.forename: F Nawaz
authors.initials: FN
authors.lastname: Khan
authors.forename: Sung Chul
authors.initials: SC
authors.lastname: Shin
authors.forename: Euh Duck
authors.initials: ED
authors.lastname: Jeong
authors.forename: Hae Gyeong
authors.initials: HG
authors.lastname: Kim
authors.forename: Mi Jin
authors.initials: MJ
authors.lastname: Kim
authors.forename: Yoon Jae
authors.initials: YJ
authors.lastname: Cho
authors.forename: Jae-Young
authors.initials: JY
authors.lastname: Cha
authors.forename: Myung Ho
authors.initials: MH
authors.lastname: Hyun
authors.forename: Jong Sung
authors.initials: JS
authors.lastname: Jin
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D043844:Crown Ethers / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000596:Amino Acids; D043844:Crown Ethers