Calibration strategies for elemental analysis of biological samples by LA-ICP-MS and LIBS – A review

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and laser-induced breakdown spectroscopy (LIBS) are widely accepted techniques for direct sampling of biological materials for elemental analysis, with increasing applications being reported over the recent years. This review is focused on the calibration materials used to quantify trace elements in different biological samples such as soft tissues (for instance brain, liver, hair) and hard tissues (bones and teeth). The design of a correct calibration strategy relies on the choice of an adapted reference material that can be commercially available or prepared in-house, which will be reviewed here. A large variety of methods has been approached and considered promising over the years, and the development of matrix-matched reference biological materials seems now closer than ever and gives hope to even better quantitation using LIBS and LA-ICP-MS.