Hollow Fiber Liquid-Phase Microextraction with in Situ Derivatization Combined with Gas Chromatography–Mass Spectrometry for the Determination of Root Exudate Phenylamine Compounds in Hot Pepper (Capsicum annuum L.)

Abstract

Hollow fiber liquid-phase microextraction (HF-LPME) with derivatization was developed for the determination of three root exudate phenylamine compounds in hot pepper ( Capsicum annuum L.) by gas chromatography-mass spectrometry (GC-MS). The performance and applicability of the proposed procedure were evaluated through the extraction of 1-naphthylamine (1-NA), diphenylamine (DPA), and N-phenyl-2- naphthaleneamine (N-P-2-NA) in a recirculating hydroponic solution of hot pepper. Parameters affecting the extraction efficiency were investigated. The calibration curves showed a good linearity in the range of 0.1-10 μg mL(-1). The limits of detection (S/N = 3) for the three compounds were 0.096, 0.074, and 0.057 μg mL(-1), respectively. The enrichment factors reached 174, 196, and 230 at the concentration of 5 μg mL(-1), and relative standard deviations (RSD) of 9.5, 8.6, and 7.8% and 8.4, 7.6, and 6.2% were obtained at concentrations of 2 and 5 μg mL(-1) for 1-NA, DPA, and N-P-2-NA, respectively. Recoveries ranging from 90.2 to 96.1% and RSDs below 9.1% were obtained when HF-LPME with in situ derivatization was applied to determine root exudate 1-NA, DPA, and N-P-2-NA after 15 and 30 days of culture solution, respectively.