Analysis of phthalates via HPLC-UV in environmental water samples after concentration by solid-phase extraction using ionic liquid mixed hemimicelles

Abstract

Ionic liquid mixed hemimicelles-based solid-phase extraction for the preconcentration of five phthalates in environmental water sample was investigated in this paper. A comparative study on the use of room temperature ionic liquids (RTILs) 1-hexyl-3-methylimidazolium bromide ([C 6 mim]Br) and 1-dodecyl-3-methylimidazolium bromide ([C 12 mim]Br)-coated silica as sorbents was presented. Owing to having bigger adsorption amounts for analytes [C 12 mim], Br-coated silica was selected as SPE material and the five analytes di-ethyl-phthalate (DEP), di-n-propyl-phthalate (DnPP), di-n-butyl-phthalate (DnBP), di-cyclohexyl-phthalate (DcHP) and di-(2-ethylhexyl)-phthalate (DEHP) can be quantitatively extracted under optimal conditions. The analytes retained on the cartridge were desorbed completely with 3 mL methanol (pH 2). Predominant factors influencing the extraction efficiency, such as RTILs concentration, pH value, ionic strength and breakthrough volume were discussed. The proposed method had been applied to determining the five phthalates in four environmental water samples and concentration factor of 600 was achieved easily. Detection limits obtained ranged between 0.12 and 0.17 g/L. The accuracy of this method was evaluated by recovery measurement on spiked samples, and good recovery results (85-107%) with relative standard deviation (R.S.D.) of below 6% were achieved.

Ionic liquids in sample preparation

“…Pretti et al [141] evaluated the acute toxicity and histological damage derived from exposure of Danio rerio (zebrafish) to several ILs (including imidazolium, pyridinium, pyrrolidinium and ammonium-based ILs). The results show that the LC 50 (96 h) values of the most commonly tested ILs (13 out of 15) were greater than 100 mg/l, which is non-highly lethal towards zebrafish, while two of them (AMMOENG 100 and AMMOENG 130) showed LC 50 values that were significantly lower than the organic solvents and tertiary amines. Docherty [142] and coauthors assessed the mutagenicity of some ILs by Ames test.…”

“…Nafion was coated onto the fiber prior to the IL coating, which enhanced the amount and stability of the IL film adsorbed onto the fiber. Recently, Li et al [50] used silica coated with [C n MIM]Br (n=8, 12) as a sorbent for the solid-phase extraction of phthalates in environmental water samples. Five target analytes were quantitatively extracted with enrichment factors as high as 600.…”

Determination of Phthalates in Polymer Materials Comparison of GC/MS and GC/ECD methods

“…In recent years, several methods for the determination of phthalates by gas chromatography (GC) [1,[5][6][7][8][9][10] and by high performance liquid chromatography (HPLC) [11][12][13][14][15][16][17][18][19][20] were described. Different methods of sample preparation and extraction have been used, such as liquid -liquid extraction (LLE) [7,21] , solid phase extraction (SPE) [1,6,11,12,16,17,21] , solid phase microextraction (SPME) [8,20,22,23] , supercritical fluid extraction [21] , microwave extraction [13,21] , Soxhlet extraction [10,21,24] and ultrasonic extraction [5,21,25] . In this paper, the studies of gas chromatography in combination with mass spectrometry detector (MS) and electron capture detector (ECD) for determination of seven kinds of phthalates, e.g.…”

Extraction of Phthalate Esters in Environmental Water Samples Using Layered-Carbon Magnetic Hybrid Material as Adsorbent Followed by Their Determination with HPLC

“…Up to now, various sample pretreatment techniques have been developed to extract PAEs from different samples, such as liquid-liquid extraction (LLE), 4,5 solid-phase extraction (SPE), [6][7][8][9] liquid-phase microextraction (LPME), 10,11 solidphase microextraction (SPME), [12][13][14][15] single-drop microextraction (SDME), 16 dispersive liquid-liquid microextraction (DLLME), [17][18][19][20] hollow fiber-based liquid-phase microextraction (HF-LPME), 21 accelerated solvent extraction (ASE) 22 and liquid-phase microextraction based on the solidification of a floating organic microdrop (LPME-SFO). 23 Among them, LLE and SPE are the most commonly used techniques for environmental analysis.…”