Solid-phase extraction: method development, sorbents, and coupling with liquid chromatography

Stir bar sorptive extraction for trace analysis

Monitoring of estrogens, pesticides and bisphenol A in natural waters and drinking water treatment plants by solid-phase extraction-liquid chromatography-mass spectrometry.

An extensive review on the consequences of chemical pesticides on human health and environment

Simultaneous quantification of neutral and acidic pharmaceuticals and pesticides at the low-ng/l level in surface and waste water

Trace analysis of pesticides by gas chromatography

The ASPEC (Automatic Sample Preparation with Extraction Columns) system has been coupled on-line to capillary GC-ECD by means of a loop-type interface equipped with a solvent vapour exit. Both ASPEC and GC conditions have been optimized leading to an effective clean-up of the extracts analyzed.



By means of solid-phase extraction cartridges filled with silica, it has been possible to analyze concentrated surface water extracts for a group of 18 electron-capturing compounds present in the water at ppt levels. ASPEC-GC has also been applied to the determination of synthetic pyrethroids at ppt levels in surface water.



The complete analytical procedure is greatly facilitated by automation and miniaturization. Miniaturization results in a considerable decrease in the sample volume required. The potential of the method for the analysis of other pesticides is estimated.

Clean-up of some organochlorine and pyrethroid insecticides by automated solid-phase extraction cartridges coupled to capillary GC-ECD

On-line combination of automated micro liquid-liquid extraction and capillary gas chromatography for the determination of pesticides in water

Reversed phase LC is coupled to capillary GC by means of an on-line extraction of the LC eluent. The extract is transferred to a loop-type LC-GC interface equipped with an early vapor exit. Using a phase switch from an aqueous reversed-phase (RP)LC solvent to an organic solvent facilitates the introduction of the analyte in the GC system, since organic solvents such as hexane, pentane, and dichloromethane are more appropriate for the GC-injection technique used in this study. As the partition coefficient of an organic solvent/aqueous system is correlated to the retention mechanism of reversed phase LC, the method has a general potential in LC/GC interfacing, viz. the extractability a component from the LC mobile phase eluting above a certain capacity factor from a RPLC column can be expected to be efficient. The method is applied to the determination of residues of the fungicide fenpropimorph in barley, oats, rye, and wheat. Another application of the interface which is feasible is the on-line extraction of aqueous samples prior to large volume injection on GC-NPD. The potential of the interface for the determination of residues nitrogen containing herbicides is estimated.

Reversed‐phase LC‐GC with a nitrogen‐phosphorus detector using a loop‐type interface combined with a sandwich‐type phase separator

Deactivation of precolumns with an ultra thin film of OV-1701 provided inertness at least equal to silylation, but better resistance to water Dynamic coating of the raw fused silica capillary is, furthermore, much faster than the hydrothermal treatment/silylation procedure

G. René van der Hoff

Papers

Trace analysis of pesticides by gas chromatography

Clean-up of some organochlorine and pyrethroid insecticides by automated solid-phase extraction cartridges coupled to capillary GC-ECD

On-line combination of automated micro liquid-liquid extraction and capillary gas chromatography for the determination of pesticides in water

Reversed‐phase LC‐GC with a nitrogen‐phosphorus detector using a loop‐type interface combined with a sandwich‐type phase separator

Deactivation of precolumns for capillary GC by a thin layer of OV‐1701