Multiresidue procedures for determination of triazine and organophosphorus pesticides in water by use of large-volume PTV injection in gas chromatography

Abstract

Two procedures, based on large-volume injection with a programmed-temperature vaporizer (PTV), have been developed for the determination of several triazine and organophosphorus pesticides. The use of PTV for injection in gas chromatography (GC) has enabled the introduction of up to 200 ~L sample extract into the GC, thus increasing the sensitivity of the method. PTV injection has been combined off-line with two different microextraction procedures liquid-liquid partition and solid-phase extraction. A simple and rapid off-line liquid-liquid microextraction procedure (5 mL water/1 mL methyl tert-butyl ether) was applied to surface water samples spiked at levels between 0.01 and 5 #gL -1. Recoveries of the overall procedure were >80% and the precision was better than 15 %. Detection limits were <30 ng L 1 from 200-#L injections in GC-NPD analysis of triazines and GC-FPD analysis of organophosphorus pesticides. Off-line automated solidphase extraction with Cls cartridges has been applied to water samples (50 mL) spiked at 0.01, 0.1 and 1 #g L 1. The overall procedure was satisfactory (recoveries >80 % and coefficients of variation <12 %) and the limits of detection ranged from 1 to 9 ng L 1. Finally, several surface water samples were analysed, and triazine herbicides were detected at concentrations of approx. 0.1 0.2 #g L 1. The results were similar to those obtained by conventional solvent extraction then GC-MSD after splitless injection of 2/~L.

Multiresidue Method for Determination of 67 Pesticides in Water Samples Using Solid-Phase Extraction with Centrifugation and Gas Chromatography-Mass Spectrometry

“…With this in mind, two solid phase sorbents were chosen, Chromabond C 18 and Oasis HLB. Both sorbents have been applied widely in the research of environmental pollutant chemistry [11,12], and they proved to be suitable for pesticides extraction from water samples [7,[13][14][15][16].…”

Large-volume injection combined with gas chromatography/isotope ratio mass spectrometry for the analysis of polycyclic aromatic hydrocarbons

“…vapor‐overflow, loop‐type injection or on‐column injection . Using Large‐Volume Injection (LVI), not only large amounts of organic solvents can be introduced to the injector, but also aqueous solutions …”

Advantages of a programmed temperature vaporizer inlet and parallel factor analysis in the determination of triazines in the presence of non-intentionally added substances by gas chromatography

“…For instance, [14] shows the determination of 141 pesticide residues in apple juice. This kind of injection has been used to determine triazines and organophosphorus pesticide residues [15], drugs of abuse in biological fluids [16], polychlorinated biphenyls (PCBs) [17], phenols [18] and phthalates [19] in aqueous samples, estrogenic compounds in environmental samples [20], and dioxins in food and feed by means of PTV/GC/MS/MS [21], among many other possibilities. Real-world application examples of LVI techniques are collected together in [10].…”