Analysis of 35 priority semivolatile compounds in water by stir bar sorptive extraction–thermal desorption–gas chromatography–mass spectrometry

Optimisation of stir bar sorptive extraction and liquid desorption combined with large volume injection-gas chromatography–quadrupole mass spectrometry for the determination of volatile compounds in wines

“…3b. For the 10 volatile compounds under study, the inlet temperature at 0 • C gave, in general, unexpectedly smaller peak areas compared with those obtained at 10 or 20 • C. The mass transfer of the trapped analytes from the PTV inlet to the column is less effective at 0 • C due probably to water condensation and frosting of the injection port, a phenomenon that was also reported by León et al [14]. Therefore, as the higher reproducibility and recovery were observed for 10 • C this was the cryofocusing inlet temperature selected for the further experiments.…”

Stir bar sorptive extraction for the analysis of short‐chain chlorinated paraffins in water

“…All the glass tubes containing a twister were placed in a magazine which is assembled in the TDSA autosampler, and were successively introduced into the thermodesorption module by the autosampler. For desorption of the stir bars, the conditions optimised in a previous study developed for compounds with similar properties were chosen [24]. The stir bars were thermally desorbed in the solvent venting mode at 408C, ramped at 608C/min to 2808C and held for 8 min and the analytes were transferred with a helium flow rate of 50 mL/min to the PTV injector.…”

“…To the best of our knowledge, none of the published papers reports the use of SBSE for the analysis of CPs. The SBSE technique has been used with excellent results for the analysis of pesticides [24,25], PAHs [24, 26 -29], PCBs [30], PBDEs [31], alkylphenols and bisphenol A [32,33], etc.…”

Environmentally friendly analysis of emerging contaminants by pressurized hot water extraction–stir bar sorptive extraction–derivatization and gas chromatography–mass spectrometry

“…2b). In general, addition of NaCl reduced the extraction of most of the apolar compounds (e.g., HHCB, OC, NP, and others having a log K ow value higher than 5) by more than 30 %, which can presumably be attributed to enhanced sorption onto the glass walls [21,24]. The opposite effect was observed for some of the more hydrophilic compounds (e.g., DEP and amitriptyline) but this benefit was not offset by large losses generated in other compounds.…”

“…Higher percentages of methanol (30 %) were also tested (data not shown) but this proved to decrease dramatically (>30 %) the affinity for the PDMS bar of most compounds, except very hydrophobic fragrances. Extraction recovery percentages decreased progressively for most compounds within the medium to high polarity range (e.g., gemfibrozil, diclofenac, TCS, and DBP) as larger volumes of methanol were added to the samples [24]. Overall, and due to the combination of enhanced extraction of highly hydrophobic analytes from water samples and the need to add methanol to improve extraction of solid samples by PHWE (see below), 10 % methanol was selected [26].…”