Analysis of Dimethylsulphoniopropionate (DMSP), Betaines and other organic solutes in plant tissue extracts using HPLC

An HPLC method using a cation-exchange column and UV detection for the simultaneous determination of dimethylsulphoniopropionate (DMSP), glycinebetaine, prolinebetaine, proline and arginine in plant tissue extracts is described. Recoveries of DMSP and glycinebetaine in either 5% perchloric acid, or methanol:chloroform:water (12:5:1) extracts of sugarcane leaf tissue were 94.0-95.4%, Proline was resolved in the 5% perchloric acid extract (recovery was 93.8%), whereas in the methanol:chloroform: water extract quantification of proline was not possible due to interference by unidentified compounds. Retention times of DMSP and arginine were increased when the pH of the mobile phase was decreased from 4.6 to 3.5, and the adjustment of the pH of the mobile phase was shown to be necessary in order to resolve DMSP in extracts from sugarcane leaves. The quantification of DMSP in sugarcane leaves using the HPLC method was compared with an indirect GC method, and the values obtained using GC were 1.14-1.65-fold higher. This discrepancy remains to be resolved. The detection limit for DMSP using the HPLC technique was about 2 mu mol/g dry weight, while for the GC method it was 0.04 mu mol/g dry weight. Copyright (C) 2000 John Wiley & Sons, Ltd.