Reducing evaporative crosstalk in urine assays using 96-well plates

LC-MS/MS analysis of volatile analytes is problematic when 96-well plates are used. Solid phase extraction of urine with high drug concentrations can cause contamination of the elution solvent during evaporation as the compounds volatilize then redistribute in adjacent wells. This phenomenon, known as “evaporative crosstalk”, can generate false positive results. Controlling crosstalk in samples with very high concentrations is particularly difficult for analytes like sympathomimetic amines. Addition of HCl in methanol (MeOH) to extracted samples before evaporation is used to reduce crosstalk. The type of evaporator, conditions and solvents used can all contribute to crosstalk. The Biotage® ACT Adapter was designed to reduce  crosstalk during evaporation.

Literature number: P223.V.1