Frequently Asked Questions How stable are NPS columns?
With the absence of pores and “internal pore blockage”, NPS columns offer high stability without sacrificing selectivity and efficiency. Internal studies are available upon request to show the high stability performance of NPS columns. Examples: 1) A study involving plasma matrices using an acidic washdown demonstrates excellent stability of retention time as well as column stability after more than 800 injections. Two different lots of 1.5ยต NPS and three different lots of bonded batches, over a period of one year, gave reproducible retention times within 1% of the mean. 2) A study of Vitamin A & E in blood serum shows no degradation on NPS after 1800 injections. 3) A study of 1000 injections of unfiltered commercial products (500 injections of a cough syrup plus 500 injections of a hand lotion) onto a NPS column showed no signs of degradation. After only a few hundred injections of the cough syrup onto a conventional porous silica based column, significant loss in selectivity was obse
