Determination of Nine Fungicides in Grape and Wine Using QuEChERS Extraction and LC/MS/MS Analysis.

An analytic procedure was developed for the determination of the fungicides ametoctradin, boscalid, cyazofamid, dimethomorph, fenhexamid, kresoxim-methyl, mepanipyrim, metrafenone, and pyraclostrobin in grape and wine. A modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) procedure was used for the extraction. Analysis of the extract was performed by LC/triple quadrupole-MS/MS. A Poroshell 120 EC-C18 column was used with a programmed gradient mobile phase consisting of (A) acetonitrile containing 0.1% formic acid and (B) water containing 0.1% formic acid and 2 mM ammonium formate. The acceptance criteria for the method were those proposed in the SANCO guide. The method was linear for the range of concentration studied (5-100 µg/L), and R2 values were higher than 0.998 and RSD values below 18%. Recovery was over 73.2% in grape and 76.7% in wines, and there was no case of more than 100% recovery. The recovery RSDs in reproducibility conditions were below 17.13% in grape and 15.6% in wines.

Determination of natural pesticides in fresh fruits using liquid chromatography/mass spectrometry.

An analytical procedure was developed for the determination of some natural pesticides (piperonyl butoxide, nicotine, rotenone, spinosad, and abamectin B1a) in fruit matrixes. The quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was used for extraction. Analysis of the extract was performed by LC-electrospray ionization (ESI)-MS/MS. The ions prominent in the ESI spectra were [M+Na]+ for abamectin B1a, [M+NH4]+ for piperonyl butoxide, and [M+H]+ for the rest of the compounds. A Zorbax SB-C18 column was used with a programmed gradient mobile phase consisting of (A) water containing 0.1% formic acid and 5 mM ammonium formate, and (B) acetonitrile containing 2 mM sodium acetate. The method was linear within the investigated concentration range, displaying a calibration curve correlation factor of 0.99. The CVs obtained were below 20%, and recoveries were in the 70-110% range.

Determination of sixteen pesticides in peppers using high-performance liquid chromatography/mass spectrometry.

A method for the detection and quantification of 16 pesticides: flufenoxuron, fenoxycarb, dimethomorph, acetamiprid, imidacloprid, lufenuron, thiacloprid, thiabendazole, thiophanate-methyl, spinosad, fenbutatin oxide, methoxyfenozide, oxamyl, clothianidin, thiamethoxam and carbendazim has been developed based on high-performance liquid chromatography-mass spectrometry. Pesticide residues were extracted from the samples according to the QuEChERS method which stands for quick, essay, cheap, effective, rugged and safe. Homogenised analytical portions (10 g ± 0.1) of samples of peppers were spiked at two levels (10 and 100 µg kg⁻¹) with a small volume of an appropriate standard mixture solution containing each pesticide. Analyses were performed using electrospray ionization (ESI) and a MSD trap system. Chromatography separation was achieved using a ZORBAX SB-C18 3.5 µm particle size analytical column, 2.1 × 50 mm from Agilent, with gradient elution at a flow-rate of 0.4 mL/min with mobile phases: waters-0.1 % HCOOH-5 mM HCOONH4 and MeOH-5 mM HCOONH4. The method has been validated based on the SANCO European Guidelines. Under the optimized conditions the recoveries (n = 7) were in the range 70-110 % with satisfactory precision (CV ≤ 20 %). A linear dynamic range was obtained over a range of concentrations from 10 to 100 µg kg⁻¹ for each of the analytes, with correlation coefficients >0.997.

Validation of an analytical method for the quantification of pyrethrins on lemons and apricots using high-performance liquid chromatography/mass spectrometry.

An analytical procedure has been developed for the determination of natural pyrethrins (pyrethrin I, pyrethrin II, jasmolin I, jasmolin II, cinerin I and cinerin II) in lemon and apricot. The QuEChERS method, which stands for quick, easy, cheap, effective, rugged and safe was used for extraction. Analysis of the extract was performed by liquid-chromatography-electrospray ionisation-tandem mass spectrometry. The ions prominent in the ESI spectra were [M+H]+ for the six compounds. A Zorbax SB-C18 column was used with a programmed gradient mobile phase consisting of (A) water containing 0.1% formic acid and 5 mM ammonium formate and (B) ACN. The method was linear within the investigated concentration range, displaying a calibration curve correlation factor of 0.99. The coefficients of variation obtained (RSD) were below 20% and the recoveries were in the 70-110% range.