An emerging analytical tool for highly sensitive quantitative analysis based on liquid chromatography-multiple-reaction monitoring cubed (MRM³)

Liquid chromatography-multiple-reaction monitoring (LC-MRM) has been widely recognized as the golden standard for multiple components-targeted quantitative analysis of complicated matrices,with extensive applications for analysis in such fields as chemical drugs, traditional Chinese medicines and foods.Unfortunately, when facing the task of quantitatively analyzing trace chemical components in complex matrices, MRM suffers dramatically from the background noise or matrix interference, leading to undesirable sensitivity and selectivity in terms of the lower limits of quantification (LOQ) and detection (LOD).In recent years, MRM cubed (MRM³), also known as MS³ scan, has received much attention because of its unique ability to significantly improve detection selectivity and sensitivity attributing to the successive ion filtering function, enabling LC-MRM³ as an emerging analytical tool.In this review,our attention is devoted to: 1) the illustration of the principle for MRM³; 2) parameter settings; and 3) the application progress of LC-MRM³ in such fields as the pursuit of biomarkers, pharmaceutical analysis, forensic analysis, toxicological analysis, food chemistry, and environmental analysis, aiming to provide a promising analytical tool of LC-MRM³ advantageous in the quantification analysis of trace chemical components in complex matrices.