Fluoroalkyl chloroformates in treating amino acids for gas chromatographic analysis.

Novel fluoroalkyl chloroformates with three and four carbon atoms were investigated for the immediate conversion of amino acids into hydrophobic derivatives in water-containing media. Derivatization conditions were extensively studied and optimized sample preparation protocols elaborated. More than 30 amino acids were treated with the particular reagent in isooctane by simply vortexing the reactive organic phase with a slightly basified aqueous medium containing pyridine or 3-picoline as a catalyst.

Gas chromatographic analysis of amino acid enantiomers in Carbetocin peptide hydrolysates after fast derivatization with pentafluoropropyl chloroformate.

A novel sample preparation protocol for gas chromatographic (GC) analysis of amino acid enantiomers in peptides was developed. It comprises traditional acid hydrolysis, a novel treatment of the analytes with a fluoroalkyl chloroformate and GC/FID separation of enantiomers on a chiral capillary column. The major improvements consist in that the derivatization step proceeds in organic-aqueous media within seconds and the amino acid derivatives are volatile enough to suit the temperature range of the chiral Chirasil-Val capillary column.

Determination of D- and L-amino acids produced by cyanobacteria using gas chromatography on Chirasil-Val after derivatization with pentafluoropropyl chloroformate.

A rapid and simple method was developed for the determination of free amino acids (AAs) released from cyanobacteria. The procedure involves trapping of AAs from the centrifuged cyanobacterial culture fluid on a cation-exchange resin, their release together with the resin by direct treatment with the reaction medium, followed by immediate derivatization with a corresponding chloroformate. The extractive alkylation transfers the analytes into an organic phase, an aliquot of which is subjected to GC analysis.

(R)-2-{2-[(S)-(2'-Benzo-yloxy-1,1'-binaphthyl-2-yl)oxycarbonyl-amino]-3-phenylpropanamido-meth-yl}pyridinium picrate acetone solvate.

In the crystal structure of the title compound, C(43)H(34)N(3)O(5) (+)·C(6)H(2)N(3)O(7) (-)·C(3)H(6)O, the large dimension and shape of the cation are responsible for the elongation of the ortho-rhom-bic unit cell. The ions and acetone mol-ecules are linked together by a system of hydrogen bonds involving an inter-molecular hydrogen bond between one N atom of the cation and the O atom of acetone and two inter-molecular hydrogen bonds between the cation N atoms and the O atoms of the picrate anion. No intra-molecular hydrogen bonds exist in the structure.