UNUSUAL ANALYTE ADSORPTION EFFECTS ON INERT LC COMPONENTS

The use of injector loops made of the inert polymer PEEK(TM) was studied for the analysis of non-steroidal anti-inflammatory drugs (NSAID) using microbore LC with peak compression. Surprisingly it was found that the use of PEEK not only failed to prevent adsorption of analyte in the loop but, in this instance, actually exacerbated the problem. The effect of loop overfill volume, competing NSAID in the sample solution and percentage organic component in the mobile phase on this phenomenon was investigated. Comparison was also made between PEEK(TM) and other materials used for injector loops.