Optimization of Solid-Phase Microextraction Procedure Coupled to GC-ECD for Triazole Fungicides Determination in Juice Samples

Abstract

A solid-phase microextraction (SPME) procedure followed by gas chromatography electron capture detection (GC/ECD) for the determination of triazole residues was developed. An experimental design with two steps was done. Firstly, a 2 6−2 fractional factorial design for screening several experimental variables (fiber-coating type, extraction temperature, extraction time, stirring rate, desorption temperature, and desorption time) was done. After, a twofactor central composite design for optimizing, the experimental conditions were carried out. The chosen experimental conditions were: fiber, PDMS/DVB; extraction time, 45 min; extraction temperature, 60°C; desorption time, 3 min; desorption temperature, 260°C, and stirring speed, 500 rpm. Using those conditions the limits of detection obtained for tetraconazole, myclobutanil, and diniconazole were in the order of few μg L −1 in grape and apple liquid extracts. Recoveries were from 93.6% to 112.1%. Relative standard deviation ranged from 1.2% to 11.6% (apple) and 6.7 to 18.0% (grape). The method was applied to five grape samples and 13 apple samples collected in Navarra, Rioja, and Basque Country. Quantification was performed by the standard addition method. Three standard additions by duplicate covering adequate range concentration were used. Myclobutanil was found in three apple samples (110-122 μg L −1 ) and diniconazole in one grape sample (9.4 μg L −1 ).

Vortex-Assisted Ionic Liquid Dispersive Liquid-Liquid Microextraction Coupled with High-Performance Liquid Chromatography for the Determination of Triazole Fungicides in Fruit Juices

“…Considering the fact that fruit juices are becoming more and more popular, it is necessary to develop sensitive and selective methods for the analysis of triazole fungicide residues usually present in trace amounts. Many chromatographic analytical methods for the trace determination of triazole fungicide residues in water and fruit juice samples included gas chromatography (GC) (Bordagaray et al 2011;Farajzadeh et al 2010Farajzadeh et al , 2011Farajzadeh et al , 2012Farajzadeh and Khoshmaram 2013;Freitas et al 2014;Li et al 2014;Sarafraz-Yazdi et al 2012), GC with mass spectrometry (GC-MS) (Farajzadeh et al 2012;Freitas et al 2014;Sarafraz-Yazdi et al 2012), GC with tandem mass spectrometry (GC-MS/MS) (Li et al 2011, highperformance liquid chromatography (HPLC) (Bordagaray et al 2013(Bordagaray et al , 2014Gao et al 2012;Luo et al 2013;Wang et al 2011;Ye et al 2012), HPLC with tandem mass spectrometry (HPLC-MS/MS) (Juan-Garcia et al 2004;Li et al 2013;Wang et al 2014;Zhang and Xu 2014), and capillary electrophoresis (CE) (Chicharro et al 2003;Rodriguez et al 2001;Wu et al 2001). On the other hand, quick and effective sample preparation coupled with a reliable analytical method is imperative.…”

Air-assisted liquid–liquid microextraction by solidifying the floating organic droplets for the rapid determination of seven fungicide residues in juice samples

“…Compared with the solid phase microextraction (SPME) [26,27] and single-drop microextraction (SDME) [23] methods, which require a extraction time longer than 30 min, the proposed AALLME-SFO method took less than 1 min to achieve a full extraction due to the large surface area between the fine droplets of the extraction solvent and the aqueous sample. Additionally, no relatively expensive special instruments such as magnetic stir bars or SPME fibers was required.…”

Use of SPME and Chemometrics in Method Development for Food and Environmental Analysis of Pesticide Residues

“…Multivariate calibration can be applied to near Infrared (NIR), reflectance analysis as well as to NMR, IR, UV, chromatography (GC, HPLC), thermal analysis, image analysis and electrophoresis [96]. The methods include partial least squares (PLS), principal component regression (PCR), classical least squares (CLS), inverse least squares (ILS), cluster analysis, discriminant analysis and artificial neutral network.…”