Determination of Chlorophenols and Alkylphenols in Water and Juice by Solid Phase Derivative Extraction and Gas Chromatography–Mass Spectrometry

Abstract

A solid phase derivative extraction method using acetic anhydride was developed for the determination of chlorophenols and alkylphenols in water and fruit juice by gas chromatography–mass spectrometry (GC–MS). The quantitative extraction was performed by passing 100 mL of sample prepared in 0.1 mol L⁻¹ sodium hydroxide through a column packed with 500 mg of a strong anion-exchange resin at a flow rate of 0.75 mL min⁻¹. The retained phenols were quantitatively derivatized in the column by the introduction of 0.25 mL of acetic anhydride. The derivatized phenols were eluted with 3.0 mL of hexane and the effluent was dried under nitrogen. The final volume was diluted to fifty microliters with hexane and analyzed by GC–MS. Under the optimum conditions, preconcentration factors of 2000, limits of detection between 0.005 and 1.796 µg L⁻¹, and relative standard deviations of 2.1% to 6.7% were obtained. The method was successfully applied to wastewater and fruit juice and the recoveries of phenols were between 76% and 111%.

Keywords:

• Alkylphenols
• Chlorophenols
• Fruit juice
• Gas chromatography–Mass spectrometry
• GC–MS
• Solid phase derivatization
• Wastewater

Notes

^a RSD, peak area ratios for 5 µg L⁻¹ each phenols.

^b LOD, limit of detection S/N = 3.

^c LOQ, limit of quantification S/N = 10.

4-MP: 4-methylphenol; 2,4-DMP: 2,4-dimethylphenol; 4-EP: 4-ethylphenol; 2,6-DCP: 2,6-dichlorophenol; 4-t-BP: 4-tert-butylphenol; 2,4,6-TCP: 2,4,6-trichlorophenol; o-PP: o-phenylphenol; 2,3,4,6-TeCP: 2,3,4,6-tetrachlorophenol; 4-t-OP: 4-tert-octylphenol; PCP: pentachlorophenol; and 4-n-NP: 4-n-nonylphenol.

Note: Sample volume: 100 mL, n = 3.

ND: Not detected; 4-MP: 4-methylphenol; 2,4-DMP: 2,4-dimethylphenol; 4-EP: 4-ethylphenol; 2,6-DCP: 2,6-dichlorophenol; 4-t-BP: 4-tert-butylphenol; 2,4,6-TCP: 2,4,6-trichlorophenol; o-PP: o-phenylphenol; 2,3,4,6-TeCP: 2,3,4,6-tetrachlorophenol; 4-t-OP: 4-tert-octylphenol; PCP: pentachlorophenol; and 4-n-NP: 4-n-nonylphenol.

^a Extraction time, centrifugation time, desorption time; LOD: Limit of detection; RSD: Relative standard deviation; SPDE/GC-MS: Solid phase derivative extraction/ Gas chromatography coupled to mass spectrometry; 4-MP: 4-methylphenol; 2,4-DMP: 2,4-dimethylphenol; 4-EP: 4-ethylphenol; 2,6-DCP: 2,6-dichlorophenol; 4-t-BP: 4-tert-butylphenol; 2,4,6-TCP: 2,4,6-trichlorophenol; o-PP: o-phenylphenol; 2,3,4,6-TeCP: 2,3,4,6-tetrachlorophenol; 4-t-OP: 4-tert-octylphenol; PCP: pentachlorophenol; 4-n-NP: 4-n-nonylphenol; HF-LPME: Hollow fiber based liquid phase microextraction; SPE: Solid phase extraction; SBSE: Stir bar sorptive extraction; LPE: Liquid phase extraction; IL-SPME: Ionic liquid-coated solid-phase microextraction; UA-HF-LLLME: ultrasound-assisted hollow fiber liquid-liquid-liquid microextraction; MASE: Membrane assisted solvent extraction; SPDE: Solid phase derivative extraction; GC/MS: Gas chromatography coupled to mass spectrometry; HPLC-DAD/FLD: High performance liquid chromatography coupled to a diode array detector and/or fluorescence detector; GC-AED/MS: Gas chromatography with atomic emission spectrometry/mass spectrometry; LC/MS: Liquid chromatography coupled to mass spectrometry; HPLC-UV: High performance liquid chromatography coupled to ultraviolet-visible spectrophotometry.