scholarly journals Determination of Thiabendazole in Orange Juice and Rind by Liquid Chromatography with Fluorescence Detection and Confirmation by Gas Chromatography/Mass Spectrometry After Extraction by Matrix Solid-Phase Dispersion

2004 ◽  
Vol 87 (3) ◽  
pp. 664-670 ◽  
Author(s):  
Beatriz Albero ◽  
Consuelo Sánchez-Brunete ◽  
José L Tadeo

Abstract A method was developed for the determination of thiabendazole (TBZ) in orange juice and rind based on matrix solid-phase dispersion (MSPD). TBZ was extracted with ethyl acetate and the extract was subsequently cleaned up on a solid-phase extraction column. Fungicide residues were determined by liquid chromatography with fluorescence detection. Recoveries through the method ranged from 87 to 97% with relative standard deviations ≤11%. The detection and quantitation limits were 0.15 and 0.50 μg/kg, respectively. The confirmation of TBZ residues in positive samples was performed by solid-phase microextraction followed by gas chromatography with mass spectrometric detection using selected ion monitoring. The developed method was applied to determine TBZ levels in commercial orange juices and in juice and rind of fresh oranges. The influence of storage and washing of fruits on TBZ residues was also studied.

2003 ◽  
Vol 86 (3) ◽  
pp. 521-528 ◽  
Author(s):  
Zhao-Yang Li ◽  
Zhi-Chao Zhang ◽  
Qi-Lin Zhou ◽  
Qing-Min Wang ◽  
Ru-Yu Gao ◽  
...  

Abstract The separation of enantiomers and diastereomers of 8 commonly used pesticides was investigated by liquid chromatography (LC) using a Chiralcel OD column (cellulose tris-3,5-dimethylphenyl-carbamate as the chiral stationary phase) and a Pirkle-type Chirex 3020 column (urea derivative from the reaction of (R)-1-(α-naphthyl)ethylamine with (S)-tert-leucine, chemically bonded to 3-aminopropylsilanized silica as the chiral stationary phase). The pesticides studied included one organophosphorus insecticide (phenthoate), 3 triazole fungicides (uniconazole, diniconazole, and propiconazole), and 4 pyrethroids (fenpropathrin, β-cypermethrin, β-cyfluthrin, and α-fenvalerate). The enantiomers were separated within 20 min with a resolution of ≥1.5 using a mixture of n-hexane and 2-propanol as the mobile phase for all the pesticides studied except propiconazole, for which only the 2 diastereomers were baseline separated. This method allows determination of the enantiomers or stereoisomers of the above pesticides in soil. The strategy was as follows: (1) First, the total concentration(s) of the enantiomer pair(s) of a chiral pesticide in soil was (were) determined by a newly developed matrix solid-phase dispersion (MSPD) procedure, followed by silica-based LC quantification. The recoveries ranged from 76.5 to 93.6% with relative standard deviations of 6.0%. (2) Second, the enantiomeric ratio(s) (ER(s)) of the chiral pesticide was (were) determined by LC with a chiral stationary phase after fractionation of the MSPD extract by silica-based LC. The determined ERs or stereoisomeric ratio(s) (SR(s); for propiconazole, only the SR of the 2 diastereomers was determined) in soil samples spiked with the above 8 racemic pesticides agreed with those of the corresponding standard solutions. (3) Third, based on the total concentrations and the corresponding ERs, the concentration of each enantiomer in soil was calculated. The proposed method is rapid, precise, and sensitive, and is appropriate for the investigation of the stereo- and enantioselective degradation of pesticides in environmental media.


2001 ◽  
Vol 84 (4) ◽  
pp. 1165-1171 ◽  
Author(s):  
Beatriz Albero ◽  
Consuelo Sánchez-Brunete ◽  
José L Tadeo

Abstract A multiresidue method was developed for the determination of 15 pesticides (organochlorines, organophosphorus compounds, pyrethroids, and other acaricides) in various commercial honeys (eucalyptus, lavender, orange, rosemary, and multifloral). The analytical procedure is based on the matrix solid-phase dispersion of honey in a mixture of Florisil and anhydrous sodium sulfate; the mixture is placed in small plastic columns and extracted with hexane–ethyl acetate (90 + 10, v/v). The pesticide residues are determined by capillary gas chromatography with electron-capture detection. Recoveries with the method at concentrations between 0.15 and 1.5 μg/g ranged from 80 to 113%, and relative standard deviations were <10% for all the pesticides studied. The pesticide detection limits were within the range 0.5–5 mg/kg for organochlorines, around 3 μg/kg for the chlorinated organophosphorus pesticides studied, near 15 μg/kg for fluvalinate, and about 3 μg/kg for the other pyrethroids.


2003 ◽  
Vol 86 (3) ◽  
pp. 576-582 ◽  
Author(s):  
Beatriz Albero ◽  
Consuelo Sánchez-Brunete ◽  
José L Tadeo

Abstract A multiresidue method was developed for the determination of 16 polycyclic aromatic hydrocarbons (PAHs) in unifloral and multifloral honeys. The analytical procedure is based on the matrix solid-phase dispersion of honey on a mixture of Florisil and anhydrous sodium sulfate in small glass columns and extraction with hexane–ethyl acetate (90 + 10, v/v) with assisted sonication. The PAH residues are determined by gas chromatography with mass spectrometric detection using selected-ion monitoring. Average recoveries for all the PAHs studied were in the range of almost 80 to 101%, with relative standard deviations of 6 to 15%. The limits of detection ranged from 0.04 to 2.9 μg/kg. The simultaneous extraction and cleanup of samples makes this method simple and rapid, with low consumption of organic solvents.


2008 ◽  
Vol 91 (1) ◽  
pp. 252-258 ◽  
Author(s):  
Qiong-Hui Zou ◽  
Jin Wang ◽  
Xiang-Feng Wang ◽  
Yuan Liu ◽  
Jie Han ◽  
...  

Abstract A novel method for simultaneous determination of 8 sulfonamide residues (sulfathiazole, sulfapyridine, sulfadiazine, sulfamerazine, sulfamonome-thoxine, sulfachloropyridazine, sulfamethoxazole, and sulfadimethoxine) in honey samples by high-performance liquid chromatography (HPLC) has been developed on the basis of precolumn derivatization with 9-fluorenylmethyl-chloroformate (FMOC-Cl). Sulfonamide residues in honey samples were extracted and purified by matrix solid-phase dispersion with C18 as the solid support. The residues were derivatized by FMOC-Cl, and the FMOC-sulfonamide derivatives were further purified by solid-phase extraction with silica gel as the solid support prior to HPLC analysis. The average recoveries for most sulfonamide compounds at different spiking levels (from 10 to 250 g/kg) were >70 with relative standard deviations <16, and their limits of detection were 4.0 g/kg. The established analytical method has high sensitivity and repeatability and can be applicable for determining the sulfonamide residues in various honey matrixes.


2020 ◽  
Vol 12 (26) ◽  
pp. 3337-3343 ◽  
Author(s):  
Zhengming Qian ◽  
Zi Wu ◽  
Chunhong Li ◽  
Guoying Tan ◽  
Hankun Hu ◽  
...  

A green and rapid matrix solid-phase dispersion extraction-liquid chromatography analytical method for the determination of ergosterol in edible fungi was established.


Sign in / Sign up

Export Citation Format

Share Document