Isoamyl nitrite depolymerized heparin as a universal calibrator for heparins and low molecular weight heparins

Because the subcutaneous absorption of heparin depends on its molecular wei ght, high performance size exclusion chromatography methods, among others, have been developed for its determination. Because heparin consists of poly mer chains of varying lengths, a large number of calibrators, 19 in our wor k, are required for these molecular weight analyses. Because the preparatio n of that many calibrants is both time-consuming and expensive, other metho ds requiring fewer calibrants are being sought. In pursuit of these aims, a heparinase-degraded heparin has been accepted as the first international r eference preparation low molecular weight heparin for molecular weight cali bration. We have previously proposed another calibrant, the Heparin Mass Ca librator. In this article, we introduce another calibrant, called the Hepar in Molecular Mass Calibrant. It offers the advantage of a much wider availa bility because it is a commercial product. In addition to having a superior refractive index chromatography run profile, when used in combination with two Narrow Range Calibrators with molecular weights of 34.4 and 18.4 KDa, this new calibrant covers both the higher and the lower molecular weight ra nges. Besides, ultraviolet detection is not needed fur molecular weight cal culations. Therefore, it is proposed that its feasibility as a universal re ference calibrator for both heparins and low molecular weight heparins be c onsidered.