Fig. 1.

General concept of the ID-LFIA direct MS approach. After a simplified extraction of the sample, a regular or smartphone-based screening LFIA is performed. If the result is suspect (“positive”), then the same extract is used to develop the ID-LFIA. In the lab followed by washing, dissociation, and rapid direct analysis by Q-orbitrap MS, or QqQ-MS/MS. Only if more specification and/or a more accurate quantification is needed, then conventional time-consuming LC-MS/MS analysis is performed, for example, for the purpose of specific regulatory requirements