A simple and robust set-up for on-column sample preconcentration--nano-liquid chromatography--electrospray ionization mass spectrometry for the analysis of N-acylhomoserine lactones.

A simple method for the simultaneous, rapid and sensitive determination of N-acylhomoserine lactone signaling molecules in bacterial isolates, without prior sample preconcentration and with minimal sample cleanup, is presented. The analysis relies on the combination of analyte preconcentration and separation on a single device: a relatively large sample volume (1-5 microL) is directly loaded onto a laboratory-made, miniaturized (75 microm i. d.