Paralytic Shellfish Poisoning (PSP) toxins are some of the most toxic substances known to man and consumption of shellfish containing these naturally-occurring neurotoxins can lead to a range of different symptoms including death in extreme cases. It is imperative therefore, to implement robust shellfish monitoring programs to minimise the possibility of contaminated product reaching the marketplace. To improve the quality assurance of these programs, QUASIMEME, the
proficiency test provider added to its scope PSP toxins in shellfish. Since 2009, six
proficiency testing exercises have been delivered by QUASIMEME with a total of thirty-four different laboratories submitting data using a range of different methods. These include animal and antibody based assays, together with High Performance Liquid Chromatography (HPLC) techniques using post and pre-column oxidation and more recently LC-MS/MS methodologies.
Data from these exercises is presented and laboratory performance is assessed to determine any changes in overall performance over the six rounds, together with any potential method-related performance issues. The data showed the improvement of laboratories over the six exercises with between laboratory CV% values decreasing from an average of 39% in the first year to 22% in 2014 and the average percentage of participants receiving satisfactory z-scores increasing from 50% in 2009 to over 66% in 2014.