Detection was typically set from 1000 m/z to 7000 m/z. After parameter optimization, the instrument was calibrated with CsI3 or PEG standards depending on the m/z range of the individual sample. Samples were prepared with α-cyano-4-hydroxycinnamic acid or with sinapinic acid as matrices, using the dried-droplet spotting technique (0.5-1.5 µL). Exemplarily, samples (1 g/L) were dissolved in MeOH (supplemented with 1.0 % TFA) or in MeCN. Laser power was set slightly above the threshold, typically at 50% -70%. Poisson distributions were calculated using eq 1: