A multianalyte method has been developed for the confirmation and quantitation of 16 selected post-emergence (POE) herbicides (three imidazolinones (IMIs), three diphenyl ethers (DPhEs), six sulfonylureas (SUs), two aryloxyphenoxypropionic acids, and two triazolopyrimidine sulfonanilides (SAs)) in soil samples. The method proposed takes advantage of the specificity provided by sample preparation and liquid chromatography tandem mass spectrometry (LC-MS/MS). The analytes are extracted using soil column extraction (SCE) and the extracts are cleaned up using Carbograph-1 cartridge. The final extract is evaporated to dryness, redissolved in water/acetonitrile (80/20, v/v) acidified with 15 mmol/l formic acid and analyzed using LC-MS/MS interfaced via a turbo ion spray (TISP). To establish the suitable extraction conditions for sample preparation, several variables affecting the performance of SCE, such the use of extractant, temperature, sample size, extractant volume and solvent flow rate, have been studied. Maximum yields were obtained by extraction with a solution of 0.1 mol/l KH2PO4, pH=8, at ambient temperature. In order to evaluate the matrix effect in SCE of POE herbicides, recovery experiments were performed for soil samples with different physical and chemical characteristics. The results of SCE were compared with the results of classical ultrasonication (USE) and microwave-assisted solvent extraction (MASE). The recovery data including precision were evaluated statistically. It was found that recoveries and precision of SCE compared with USE and MASE gave better results. Using SCE, the average recoveries of POE herbicides in the different samples ranged between 63 and 99%. The relative standard deviation ranged between 3 and 8%. Low detection limits at the parts per billion (ppb) level can be obtained. For confirmation, the parent ion and the product ions were monitored in the multiple reaction monitoring (MRM) mode. (C) 2000 Elsevier Science B.V. All rights reserved.
Liquid chromatography mass spectrometry tandem for multiresidue determination of selected post-emergence herbicides after soil column extraction / Lagana', Aldo; Fago, Giovanna; Marino, Aldo; Vittoria Maria, Penazzi. - In: ANALYTICA CHIMICA ACTA. - ISSN 0003-2670. - STAMPA. - 415:1-2(2000), pp. 41-56. [10.1016/s0003-2670(00)00857-6]
Liquid chromatography mass spectrometry tandem for multiresidue determination of selected post-emergence herbicides after soil column extraction
LAGANA', Aldo;FAGO, Giovanna;MARINO, Aldo;
2000
Abstract
A multianalyte method has been developed for the confirmation and quantitation of 16 selected post-emergence (POE) herbicides (three imidazolinones (IMIs), three diphenyl ethers (DPhEs), six sulfonylureas (SUs), two aryloxyphenoxypropionic acids, and two triazolopyrimidine sulfonanilides (SAs)) in soil samples. The method proposed takes advantage of the specificity provided by sample preparation and liquid chromatography tandem mass spectrometry (LC-MS/MS). The analytes are extracted using soil column extraction (SCE) and the extracts are cleaned up using Carbograph-1 cartridge. The final extract is evaporated to dryness, redissolved in water/acetonitrile (80/20, v/v) acidified with 15 mmol/l formic acid and analyzed using LC-MS/MS interfaced via a turbo ion spray (TISP). To establish the suitable extraction conditions for sample preparation, several variables affecting the performance of SCE, such the use of extractant, temperature, sample size, extractant volume and solvent flow rate, have been studied. Maximum yields were obtained by extraction with a solution of 0.1 mol/l KH2PO4, pH=8, at ambient temperature. In order to evaluate the matrix effect in SCE of POE herbicides, recovery experiments were performed for soil samples with different physical and chemical characteristics. The results of SCE were compared with the results of classical ultrasonication (USE) and microwave-assisted solvent extraction (MASE). The recovery data including precision were evaluated statistically. It was found that recoveries and precision of SCE compared with USE and MASE gave better results. Using SCE, the average recoveries of POE herbicides in the different samples ranged between 63 and 99%. The relative standard deviation ranged between 3 and 8%. Low detection limits at the parts per billion (ppb) level can be obtained. For confirmation, the parent ion and the product ions were monitored in the multiple reaction monitoring (MRM) mode. (C) 2000 Elsevier Science B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
