Selection of SPE cartridge for automated solid-phase extraction of pesticides from water followed by liquid chromatography-tandem mass spectrometry.
In environmental analyses there is an ever-increasing need to develop simple and sensitive multi-residue methods. In many agricultural regions, there is particular concern of the potential for pesticides to enter rivers and other waterways. This study reports on the development and validation of a multi-residue method of analysis for 30 pesticides in water samples using solid-phase extraction (SPE) followed by LC-MS/MS. The electrospray and MS/MS parameters were optimised for each pesticide, including capillary voltage, collision-induced dissociation voltage, and selection of a precursor ion and two product ions. A variety of SPE sorbents were tested for sample pre-concentration, including numerous polymeric based phases. Bond Elut PPL and Oasis HLB were the only phases capable of retaining the majority of the target analyte classes in a single method. An off-line pre-concentration method using a Gilson Aspec system was optimised using the Bond Elut PPL cartridges, with a concentration factor of 25 producing limits of quantitation in the order of 6-100 ng/L. Excellent linearity (r2 > 0.9), precision (<20%) and recovery (>60%) was obtained for nearly all of the analytes, covering a wide variety of chemical and physical properties. This is the first study to fully validate Bond Elut PPL cartridges for use in multi-residue pesticide analysis.
Jordan
Timothy B
TB
Analytical Services Tasmania, 18 St John's Ave, New Town, Hobart, Tasmania 7008, Australia. tim.jordan@environment.tas.gov.au
Nichols
David S
DS
Kerr
Neil I
NI
D002853:Chromatography, Liquid / Q000379:methods*; D005618:Fresh Water / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis* / Q000302:isolation & purification; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
D010573:Pesticide Residues