Determination of aryloxyphenoxypropionic acid herbicides in water using different solid-phase extraction procedures and liquid chromatography-diode array detection.
For isolation and trace enrichment of aryloxyphenoxypropionic acid (ArPP) herbicides from drinking, spring, and ground water a sensitive, robust method is presented. A 1-2 1 volume of aqueous samples was passed through a disposable solid-phase extraction cartridge, packed with 500 mg of Carbograph-1 at a flow-rate of 100 ml/min. After washing, ArPPs are selectively eluted with 8 ml of dichloromethane-methanol (80:20, v/v) with 50 mmol/1 formic acid and evaporated to dryness. The mixture was reconstituted with 250 microliters of water-acetonitrile (75:25; v/v) acidified with 0.1% trifluoroacetic acid and 100 microliters was injected into the high-performance liquid chromatography system. The ArPPs were separated via a binary gradient of water and a mixture of methanol-acetonitrile. Detection and confirmation were performed by diode array detection. Recovery of the six acid herbicides ranged between 90% and 98%. The limits of detection of ArPPs were 7-20 ng/l for drinking water and 16-36 ng/l for spring water. In terms of recovery and selectivity the effectiveness of Carbograph-1 cartridges was compared with that of LiChrolut-EN cartridges and polystyrene-divinylbenzene Empore disks. Relevant parameters such as pH and flow-rate for solid-phase extraction with divinylbenzene resins were optimized.
Laganà
A
A
Department of Chemistry, La Sapienza University, Rome, Italy.
Fago
G
G
Marino
A
A
D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006540:Herbicides / Q000032:analysis* / Q000302:isolation & purification; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000302:isolation & purification
D006540:Herbicides; D014874:Water Pollutants, Chemical