Dimethyl(3,3,3-trifluoropropyl)silyldiethylamine--a new silylating agent for the derivatization of β-blockers and β-agonists in environmental samples

Abstract

Research into alternative derivatizing agents remains a major task in the trace analysis of polar compounds using GC. DIMETRIS (dimethyl(3,3,3-trifluoropropyl)silyldiethylamine) is a new and interesting proposition in this field. This agent possesses strong nucleophilic properties and reacts selectively with hydroxyl groups. The derivatization reaction takes place in the absence of any catalysts. The derivatives possess good chromatographic properties and are easily detected by mass spectrometry. By introducing fluorine atoms into the structure of the derivatives, we were able to use an electron-capture detector for their GC determination. No degradation of new derivatives was observed after seven days of storage in a refrigerator or during the GC analyses. Unlike a number of acylation agents, DIMETRIS does not corrode the analytical equipment. In this work β-blockers and β-agonists were used for testing the derivatizing properties of DIMETRIS. Derivatization of these drugs was optimal at 30 °C for 30 min. The method quantification limits of the target compounds determined in tap water samples by SPE-GC-MS(SIM) ranged from 3 to 40 ng L(-1) and resembled those obtained with samples derivatized using a mixture of N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and 1% chlorotrimethylsilane (TMCS) (hitherto regarded as optimal). This work confirmed that DIMETRIS is suitable for the trace analysis of pharmaceuticals in natural samples and provides an interesting alternative to silylating and acylating agents.