Determination of inositol phosphates and other biologically important anions by ion chromatography

Ion chromatography has been applied to the simultaneous, multi-component determination of biologically important anions. More than 20 different biologically important anions were separated on high performance ion-exchange columns and detected using chemically suppressed conductivity. Application of the technique to the separation of inositol mono-, bis-, and trisphosphates shows that these compounds can be separated from the other ions tested and can be detected at concentrations that may be found in vivo. For inositol monophosphate, the conductivity was proportional to the amount of compound from less than 20 pmol to more than 400 nmol. Although alternative methods are available for assaying each of these anions individually, the advantages of ion chromatography lie in the sensitivity of detection, the speed of separation, and the ability to simultaneously determine numerous ions. This method should be broadly applicable to studies of second messengers, measurements of reaction rates, and various metabolic studies.