Analyses of Indole Compounds in Sugar Cane (Saccharum officinarum L.) Juice by High Performance Liquid Chromatography and Liquid Chromatography-Mass Spectrometry after Solid-Phase Extraction

Wei Wong,Zhen Ma,Liya Ge,Swee Tan,Jean Yong

doi:10.3390/separations4010007

Wei Wong, Zhen Ma + Show 3 more

Open Access

https://doi.org/10.3390/separations4010007

Copy DOI

Abstract

Simultaneous quantitative analysis of 10 indole compounds, including indole-3-acetic acid (IAA, one of the most important naturally occurring auxins) and some of its metabolites, by high performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) after solid-phase extraction (SPE) was reported for the first time. The analysis was carried out using a reverse phase HPLC gradient elution, with an aqueous mobile phase (containing 0.1% formic acid) modified by methanol. Furthermore, a novel SPE procedure was developed for the pre-concentration and purification of indole compounds using C18 SPE cartridges. The combination of SPE, HPLC, and LC-MS was applied to screen for the indole compounds present in sugar cane (Saccharum officinarum L.) juice, a refreshing beverage with various health benefits. Finally, four indole compounds were successfully detected and quantified in sugar cane juice by HPLC, which were further unequivocally confirmed by LC-MS/MS experiments operating in the multiple reaction monitoring (MRM) mode.

Highlights

Sugar cane (Saccharum officinarum L.), a widely distributed crop in the world, has many economic dimensions, especially for the sugar industry, in many tropical and subtropical countries [1]
All indole standards were purchased from Sigma-Aldrich (Steinheim, Germany) except Indole-3-acetic acid (IAA), which was obtained from PhytoTechnology Laboratories (Shawnee Mission, KS, USA)
As the column with C18 provided a better peak shape in most cases, it was used for further study

Summary

Introduction

Sugar cane (Saccharum officinarum L.), a widely distributed crop in the world, has many economic dimensions, especially for the sugar industry, in many tropical and subtropical countries [1]. In many countries where sugar cane is cultivated, general population like to drink sugar cane juice as a delicious, refreshing, and popular beverage. Sugar cane juice contains sugar, vitamins, inorganic minerals and plant growth regulators (i.e., phytohormones). Sugar cane juice has been used in the plant tissue culture industry [3], though not as widely used as coconut water [4,5]. For the tissue culture work performed in our group (unpublished data), sugar cane juice supplementation

Objectives

Methods

Results

Conclusion