Preparation of single‐walled carbon nanotube fiber coating for solid‐phase microextraction of organochlorine pesticides in lake water and wastewater

Abstract

The feasibility of single-walled carbon nanotubes (SWCNTs) as adsorbents for solid-phase microextraction was investigated by using organochlorine pesticides (OCPs) as model compounds. SWCNTs were attached onto a stainless steel wire through organic binder. Potential factors affecting the extraction efficiency were optimized, including extraction time, extraction temperature, desorption time, desorption temperature, and salinity. The developed method has a linear range of 2-800 ng/L for most analytes, with coefficients of correlation ranging from 0.9911 to 0.9996, LODs ranged from 0.19 to 3.77 ng/L (S/N = 3), and RSDs in the range of 3.5-13.9% (n = 5). Compared with the commercial PDMS fiber, the SWCNT fiber has better thermal stability (over 350 degrees C) and longer life span (over 150 times). The developed method was applied to determine trace OCPs in lake water and wastewater samples with external standard calibration. Results showed that OCP contamination was very low in these samples, and HCHs were detected in almost all water samples while DDT concentrations were almost under detection limits in these samples. Recoveries obtained at 20 ng/L spiking level were in the range of 88.4-111% for OCPs in lake water. For wastewater samples, however, the recoveries were satisfactory for HCHs (63.6-97.1%) but relatively low for DDTs (44.7-116%) due to the high content of organic matter in wastewater.

Development of Novel Solid-Phase Microextraction Fibers

“…Up to now, physical deposition [91], gluing [92][93][94][95][96][97][98][99], sol-gel method [100][101][102][103], electrophoretic deposition [104,105], depositions in conductive polymers [106][107][108][109], and chemical bonding [24,27,28,110,111] have also been adopted to immobilize CNTs on supporting substrates. Besides, CNTs and β-cyclodextrin-functionalized CNTs were also entrapped in pores of polypropylene hollow fibers for the preparation of novel SPME fibers (Fig.…”

“…• Polybrominated diphenyl ethers in water (DI [91] and HS [100]) and milk (DI [91]), • Phenols in water (DI [24,27,92,96,98,104,110,111] and HS [101,106]), • Pesticides in water (HS [28,93] and DI [108]), and tea samples (DI [95]), • Butyltin compounds in seawater (HS) [94], • p-Nitroaniline, aniline, o-dinitrobenzene in water (DI) [96], • Aniline, 4-methylaniline, 4-methoxybenzoic acid, benzyl alcohol, benzoic acid, and 3-chlorobenzoic acid in water (DI) [97], • Hydrocarbons in water (DI) and soil samples (HS) [99], • Benzene series in water (HS) [27,101,103] • Benzaldehyde, acetophenone, and 2-octanone in water (HS) [27], • Strychnine and brucine in urine (DI) [112], • Hormones of tomatoes (DI) [113].…”

Solid Phase (Micro)extraction Tools Based on Carbon Nanotubes and Related Nanostructures

“…This SPME fiber was used for the extraction of phenols from water samples by DI mode. Despite the good precision of the method, obtaining RSD values for a single fiber of 0.7-3.2%, the lifetime of the fiber decreased significantly after 80 analyses, which is shorter than that obtained with the organic binder (Lü et al, 2007). In a similar manner, Du et al (Du et al, 2009) covered a Pt fiber with a composite of MWCNTs and polyaniline (PANI) by electrochemical deposition for the determination of phenolic compounds in lake water samples.…”

“…Notwithstanding this, the procedure has been successfully used for a variety of applications. Lü et al (Lü et al, 2007) immobilized SWCNTs on a SPME fiber using an organic adhesive composed of terpineol, ethylcellulose and dibutyl phthalate. Once the fiber was coated, it was used to extract eight organochlorine pesticides in lake and wastewater samples by DI-SPME mode.…”

Polypyrrole/graphene composite‐coated fiber for the solid‐phase microextraction of phenols

“…As we know, carbon materials have high adsorption capacity for organic compounds and some of them (such as single-walled carbon nanotubes [24], multi-walled carbon nanotubes [25], activated carbon [26], and glassy carbon [27]) have already been employed in SPME. Compared with other graphitic materials, G shows many outstanding advantages, such as high surface area-toweight (2630 m 2 /g), remarkable thermal and chemical stability, and ultra-high mechanical strength [28,29].…”