Harmful algal blooms (HABs) which can produce a variety of marine biotoxins are a prevalent and growing risk to public safety. The aim of this research was to investigate, evaluate, develop and validate an analytical method for the detection and quantitation of five important groups of marine biotoxins in shellfish tissue. These groups included paralytic shellfish toxins (PST), amnesic shellfish toxins (AST), diarrheic shellfish toxins (DST), azaspiracids (AZA) and neurotoxic shellfish toxins (NST).