“…Thus far, several sample preparation techniques like conventional liquid-liquid extraction (LLE) (National Institute for Occupational Safety and Health, 2003), solid-phase extraction (SPE) (Marchese, Curini, Gentili, Perret, & Rocca, 2004), hollow fiber-liquid-phase microextraction (HF-LPME) (Ghamari, Bahrami, Yamini, Shahna, & Moghimbeigi, 2017), and dispersive assisted-solid phase microextraction (Behbahani, Bagheri, Omidi, & Amini, 2018) have been used to analyze MHAs in the urine of exposed people. However, the applications of LLE have several drawbacks, including requiring a high volume of sample, complicated sample preparation, multistep procedures, toxic organic solvents (in some cases they are expensive, produce large quantities of secondary wastes and cause environmental pollution), laboriousness and providing low pre-concentration (Bustamante et al, 2017;Golfinopoulos, Lekkas, & Nikolaou, 2001).…”