Determination of chlorinated phenoxy acid and ester herbicides in soil and water by liquid chromatography particle beam mass spectrometry and ultraviolet absorption spectrophotometry

Abstract

Eight chlorinated phenoxy acid and three ester herbicides are determined In soil and water by liquid chromatography with UV absorption for quantitation and particle beam mass spectrometry for confirmation. Chromatography (C-18 reversedphase column, 22 cm X 2.1 mm, water with methanol or acetonitrile and acetic acid mobile phase, 0.25 mL/mln flow) with UV detection (230 nm) gives quantitation limits of 12-80 ng In 10-µ . Injected volume (corresponding to 4.8-32 ppb in 125 mL of water and 20-133 ppb In 30 g of soil and 500 µ of final extract volume) with four-point calibration (ff > 0.99).Full scan electron Ionization particle beam mass spectra are given for chlorinated phenoxy acids at 1.25 pg each on-column, showing molecular and phenoxy (base) Ions. Both ackte and esters are efficiently and cleanly extracted from soli and water with ethyl acetate, and the esters are base hydrolyzed before analysis. The average recovery of eight carboxylic adds spiked Into water at 33.3, 1.0, and 0.1 ppm and spiked Into soil at 33.3 and 1.0 ppm is 78% (average standard deviation 4.2%). The average recovery and ester hydrolysis efficiency for the three esters 2,4-D mixed isobutyl, 2,4,5-T butoxyethanol ether, and 2,4-DB Isobutyl spiked at the same levels In soli and water Is 88% (average standard deviation 10%).

Overview of Analytical Techniques for Herbicides in Foods

“…The great advantage of HPLC tandem mass spectrometry (HPLC-MS/MS) is its highly selectivity, which greatly reduce the false positive results in detection. Kim (Kim et al, 1991) applied HPLC-MS to detect 2, 4, 5-T, 2, 4-D and fenoprop residues in water, which was the first application of HPLC-MS techniques in phenoxy acid herbicide detection. Ultra Performance Liquid Chromatography (UPLC) employs 1.7 um particles, resulting in a very flat VanDeemter plot and a linear velocity faster than usual one with 5 um packings; consequently, improves resolution, speed and sensitivity for many HPLC methods.…”

Is particle beam an up-to-date LC-MS interface? State of the art and perspectives

“…Phenoxy acids and ester herbicides are target compounds in another method for their determination in soil and water (Kim et al, 1991). The particle beam is used for the confirmation of UV detection results.…”

Kinetic spektrophotometric determination of 2,4-dichlorphenoxyacetic acid based on its inhibitory effect on the oxidation of sulfanilic acid by hydrogen peroxide

“…A number of analytical methods have been reported for determination of phenoxyacid herbicides in different matrices using high-performance liquid chromatography HPLC [3][4][5], gas chromatography GC-MS [6][7][8][9][10][11], capillary electrophoresis [12][13][14][15][16] and micellar electrokinetic chromatography [17]. Because of the complex structure of matrix and the presence of pesticides in small quantities, different procedures for extracting and preconcentration of pesticides from samples are needed to develop.…”