To potentially resolve the issues of sample clogging, it is important to identify the most frequent clogging location within the LC system. Analysis of our service records indicated that approximately 95% of the clogs occurred between the needle seat and the column head (Table ). To better understand why this region is so prone to accumulation of solid debris and subsequent clogging, it is instructive to examine Figure , from which we can see as would be expected that the initial point of entry of solids into the system is from the needle seat. Hence, if we can eliminate particulate build-up at this specific position, then it stands to reason that we can reduce the instances of clogging.