Combination of femtosecond laser ablation with chemometric tools for direct food sample analyses

Abstract

Advantages of analytical techniques employing laser pulses as sampling tools (for example Laser Ablation Inductively Coupled Plasma Mass Spectrometry, LA-ICP-MS) are well known in the analytical community. Its main characteristics are direct analysis of any type of samples, reduction of chemical treatment steps eliminating potential sources of contamination, and last but not least reduction of analysis time. However, one of the biggest challenges for these direct sampling approaches is performing reliable quantitative analyses. The reliability of quantitative analysis depends greatly on the availability of appropriate standard reference materials. Some of the requirements for these "appropriate" standard reference material, in particular when using nanosecond lasers, is related to matrix matching between samples and standards. Chemometric tools (for data processing) or femtosecond lasers (to improve laser-material interaction) can improve method performance minimizing matrix effects. In this project, we propose to use a combination of femtosecond laser ablation with chemometrics data analysis to establish analysis protocols for food samples quality control. Food samples are among the most variable samples in terms of matrices and elemental composition. In particular, we propose to establish calibration strategies for determination of Ca, Cd, Cr, Fe, Mg, Pb and Zn in liquid (i.e. orange juice), and solid samples (i.e. dietary supplements).