PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 14763799

Solid-phase extraction versus solid-phase microextraction for the determination of chlorinated paraffins in water using gas chromatography-negative chemical ionisation mass spectrometry.

P Castells·F J Santos·M T Galceran
View original source ↗Export metadata ↓

Abstract

Solid-phase extraction (SPE) and solid-phase microextraction (SPME) were evaluated for the analysis of short-chain chlorinated paraffins (SCCPs) in water samples using gas chromatography coupled to negative chemical ionisation mass spectrometry (GC-NCI-MS). For SPE optimisation, four commercially available SPE cartridges were tested and several SPE parameters, such as the elution solvent, elution volume and breakthrough volume were studied. The best results were obtained with Varian Bond Elut-C18. In order to achieve a high selectivity in the determination of SCCPs, GC-NCI-MS was used. Quality parameters of the optimised SPE and SPME procedures were determined, and the best results were obtained for the SPE/GC-NCI-MS method with LODs of 5 and 20 ng l(-1) for tap and river water, respectively. This method was successfully applied to the analysis of SCCPs in river water samples at concentrations below the microg l(-1) level.

Explore related subjects

ChlorineMass SpectrometryParaffinSensitivity and SpecificityJournal ArticleResearch Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

P Castells, F J Santos, M T Galceran. 2004-02-06. Solid-phase extraction versus solid-phase microextraction for the determination of chlorinated paraffins in water using gas chromatography-negative chemical ionisation mass spectrometry.. https://doi.org/10.1016/j.chroma.2003.10.069

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Monitoring the trihalomethanes present in water after treatment with chlorine under laboratory condition.

In this work assays involving chlorinated water samples, which were previous spiked with humic substances or algae blue green and following the production of the THMs for 30 days is described. To implement the assays, five portions of 1,000 ml of water were stored in glass bottles. The water samples were treated with solutions containing 2, 3, 4 and 5 mg l(-1) chlorine. The samples aliquots (60 ml) were transferred into the glass vials, 10 ml were removed to have a headspace and 100 microl of the 10 mg l(-1) pentafluortoluene bromide solution was added to each vial. The extraction step was performed by adding 10 g of Na(2)SO(4) followed by 5 ml of n-pentane. The vials were stopped with a TFE-faced septum and sealed with aluminum caps. The generated THMs were determined by gas chromatography with electron capture detector using reference solutions with concentration ranging from 8 to 120 microg l(-1) THMs. Three assays were monitored during 30 days and chloroform was the predominant compound found in the water samples, while other species of THMs were not detected. The results showed that when the chlorine concentration was increased in water samples containing algae the concentration of THM varied randomly. Nevertheless, in water samples containing humic substances the increase of the THM concentration presented a relationship with the chlorine concentration. It was also observed that chloroform concentration increased with the elapsed time up to one and six days to water samples spiked with humic substances and algae blue green, respectively and decreased along 30 days. By other hand, assays performed using water samples containing decanted algae material showed that THM was not generated by the chlorine addition.

Chlorine↗
PubMed2006

Mononuclear Ni(III) complexes [NiIII(L)(P(C6H3-3-SiMe3-2-S)3)]0/1- (L = thiolate, selenolate, CH2CN, Cl, PPh3): relevance to the nickel site of [NiFe] hydrogenases.

The stable mononuclear Ni(III)-thiolate complexes [NiIII(L)(P(C6H3-3-SiMe3-2-S)3)]- (L = SePh (2), Cl (3), SEt (4), 2-S-C4H3S (5), CH2CN (7)) were isolated and characterized by UV-vis, EPR, IR, SQUID, CV, 1H NMR, and single-crystal X-ray diffraction. The increased basicity (electronic density) of the nickel center of complexes [NiIII(L)(P(C6H3-3-SiMe3-2-S)3)]- modulated by the monodentate ligand L and the substituted groups of the phenylthiolate rings promotes the stability and reactivity. In contrast to the irreversible reduction at -1.17 V (vs Cp2Fe/Cp2Fe+) for complex 3, the cyclic voltammograms of complexes [NiIII(SePh)(P(o-C6H4S)3)]-, 2, 4, and 7 display reversible NiIII/II redox processes with E(1/2) = -1.20, -1.26, -1.32, and -1.34 V (vs Cp2Fe/Cp2Fe+), respectively. Compared to complex 2 containing a phenylselenolate-coordinated ligand, complex 4 with a stronger electron-donating ethylthiolate coordinated to the Ni(III) promotes dechlorination of CH2Cl2 to yield complex 3 (kobs = (6.01 +/- 0.03) x 10-4 s-1 for conversion of complex 4 into 3 vs kobs = (4.78 +/- 0.02) x 10-5 s-1 for conversion of complex 2 into 3). Interestingly, addition of CH3CN into complex 3 in the presence of sodium hydride yielded the stable Ni(III)-cyanomethanide complex 7 with a NiIII-CH2CN bond distance of 2.037(3) A. The NiIII-SEt bond length of 2.273(1) A in complex 4 is at the upper end of the 2.12-2.28 A range for the NiIII-S bond lengths of the oxidized-form [NiFe] hydrogenases. In contrast to the inertness of complexes 3 and 7 under CO atmosphere, carbon monoxide triggers the reductive elimination of the monodentate chalcogenolate ligand of complexes 2, 4, and 5 to produce the trigonal bipyramidal complex [NiII(CO)(P(C6H3-3-SiMe3-2-S)3]- (6).

Chlorine↗
PubMed2006

Persistence of pharmaceuticals and other organic compounds in chlorinated drinking water as a function of time.

Ninety eight pharmaceuticals and other organic compounds (POOCs) that were amended to samples of chlorinated drinking-water were extracted and analyzed 1, 3, 6, 8, and 10 days after amendment to determine whether the total chlorine residual reacted with the amended POOCs in drinking water in a time frame similar to the residence time of drinking water in a water distribution system. Results indicated that if all 98 were present in the finished drinking water from a drinking-water treatment plant using free chlorine at 1.2 mg/L as the distribution system disinfectant residual, 52 POOCs would be present in the drinking water after 10 days at approximately the same concentration as in the newly finished drinking water. Concentrations of 16 POOCs would be reduced by 32% to 92%, and 22 POOCs would react completely with residual chlorine within 24 h. Thus, the presence of free chlorine residual is an effective means for transforming some POOCs during distribution.

Chlorine↗