Derivatisation/solid-phase microextraction followed by gas chromatography–mass spectrometry for the analysis of phenoxy acid herbicides in aqueous samples

Passive extraction and clean-up of phenoxy acid herbicides in samples from a groundwater plume using hollow fiber supported liquid membranes

“…Dynamic ion-exchange solid-phase extraction (DIE-SPE), based on the ionic functional group of the surfactant adsorbed on the surface of C 18 bonded silica to act as ion-exchange sites to attract ionized phenoxy acid herbicides, was also established to eliminate the interference of humic acids [17]. Phenoxy acid herbicides in water were also extracted with solid-phase microextraction (SPME) after derivatization with benzyl bromide [18], alkylchloroformate [19] or N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide [20]. While the former two derivatization/SPME methods [18,19], with low sensitivity and poor repeatability, can only be used as screening technique; the later one [20] possesses sufficient sensitivity and good repeatability for determining phenoxy acid herbicides in real wastewater and groundwater samples.…”

“…Phenoxy acid herbicides in water were also extracted with solid-phase microextraction (SPME) after derivatization with benzyl bromide [18], alkylchloroformate [19] or N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide [20]. While the former two derivatization/SPME methods [18,19], with low sensitivity and poor repeatability, can only be used as screening technique; the later one [20] possesses sufficient sensitivity and good repeatability for determining phenoxy acid herbicides in real wastewater and groundwater samples. Supported liquid membrane (SLM) extraction, both flat membrane based [21] and hollow fiber membrane based [22,23], were also used as an alternative sample preparation technique for the determination of phenoxy acid herbicides.…”

Chemical Analysis of Pesticides Using GC/MS, GC/MS/MS, and LC/MS/MS

“…One chemical class of pesticides which has been successfully analyzed with derivatization prior to GC/MS analysis is the phenoxy acid herbicides. Derivatization agents have included pentafluorobenzyl (PFB) bromide, benzyl bromide, trimethylsilyl diazomethane, or alkylchloroformates to produce the corresponding PFB, benzyl, or methyl ester (Nilsson et al, 1998;Rimmer et al, 1996;Henriksen et al, 2001). Methylation with diazomethane or by reaction with 10% sulfuric acid in methanol has also been used (Shin, 2006).…”

Hollow fiber membrane supported thin liquid film extraction for determination of trace phenoxy acid herbicides and phenols in environmental water samples

“…These procedures usually require an appreciable amount of toxic solvent which pose threat to the environment. Therefore, solvent-free extraction technique termed as solid phase microextraction (SPME) [12,13] was adopted to preconcentrate phenoxy acid herbicides and phenols. SPME integrates sample preconcentration and injection in one step, which is very convenient to operate.…”

“…However, SPME also has some drawbacks, such as limited lifetime, fragility of fiber coating and the possibility of sample carry-over [14]. Meanwhile, derivatization is needed for the highly polar compounds such as phenoxy acid herbicides and phenols before the SPME extraction [12,13]. Additionally, SPME is best compatible with GC and less attractive in connection with liquid chromatography.…”