The use of injector loops made of the inert polymer PEEK(TM) was studi
ed for the analysis of non-steroidal anti-inflammatory drugs (NSAID) u
sing microbore LC with peak compression. Surprisingly it was found tha
t 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 phenomen
on was investigated. Comparison was also made between PEEK(TM) and oth
er materials used for injector loops.