Analysis of human luteinizing hormone and human chorionic gonadotropin preparations of different origins by reversed-phase high-performance liquid chromatography.

Specific reversed-phase high-performance liquid chromatography conditions are reported for the analysis of recombinant and native human luteinizing hormone (hLH) and human chorionic gonadotropin (hCG) preparations. Heterodimeric hLH, hCG and their alpha- and beta-subunits migrated with significantly different retention times (t(R)) in the following order of increasing hydrophobicity: alpha-hCG<alpha-hLH<hCG<hLH<beta-hCG<beta-hLH. Under these conditions, the main peak of three hCG preparations ran about 4% faster than the average t(R) (38.35+/-0.42 min; RSD=1.1%) of four hLH preparations. Four heterogeneous urinary products were also analyzed, hLH, hFSH and hCG peaks being identified. Quantitative analysis was validated for the homogeneous preparations and a highly linear dose-response curve (r=0.99998; p<0.0001; n=20) used to assess the accuracy, precision and sensitivity of the analysis. Quantification of the different gonadotropins in the heterogeneous preparations was also carried out, but with limitations in accuracy.