Determination of Pesticides in Sunflower Seeds by High-Performance Liquid Chromatography Coupled with a Diode Array Detector

2014 ◽  
Vol 97 (4) ◽  
pp. 1012-1020 ◽  
Author(s):  
Tomasz Tuzimski ◽  
Tomasz Rejczak

Abstract The application of RP-HPLC with a diode array detector for identification and quantitative analysis of pesticides in sunflower seed samples is demonstrated. An HPLC procedure on C18 RP column has been developed for analysis of selected pesticides from different chemical groups: simazine, isoproturon, terbuthylazine, linuron, captan, terbutryn, procymidone, fenitrothion, clofentezine, and bromopropylate. We investigated the possibility of expanding the scope of the four analyte extraction procedures for isolation of pesticides from plant matrixes with high levels of lipids. The following procedures were tested: A, ultrasound-assisted solvent extraction (UAE) and SPE; B, dispersive-SPE (d-SPE); C, UAE and d-SPE; and D, UAE/SPE/d-SPE. Average recoveries from spiked samples at different concentrations in the range from 0.1 to 1.40 μg/g in the plant materials and the SDs for C18 cartridges and solvents by the proposed RP-HPLC-DAD method after the extraction procedures are also presented. The efficiency of procedures A–D was evaluated using real food samples from Hungary, Bulgaria, and Poland. The quantity of terbuthylazine determined was in the range of 7.1–12.7 ng/g (n = 6), whereas the quantity of procymidone determined was in the range of 3.7–5.7 ng/g (n = 3) in plant materials. The quantities of pesticides determined in sunflower seeds were below the maximum residue levels (excluding captan) established in the European Union legislation. The method was validated for precision and accuracy.

2012 ◽  
Vol 95 (5) ◽  
pp. 1357-1361 ◽  
Author(s):  
Tomasz Tuzimski

Abstract The application of HPLC-diode array detector (DAD) after SPE for identification and quantitative analysis of pesticides in red and green pepper samples is demonstrated. An HPLC procedure on an RP column (C18) was developed for analysis of selected pesticides from different chemical groups: metamitron, metalaxyl, linuron, and prometryn. Average recoveries for C18 Polar Plus cartridges and solvents by the proposed RP-HPLC-DAD method after SPE are presented. Average recoveries from the spiked samples and the SDs were 22.5 ± 2.2, 138.0 ± 4.1, 78.6 ± 2.8, and 109.2 ± 2.3% for metamitron, metalaxyl, linuron, and prometryn, respectively, at concentrations of 7 μg/g in the plant material. The efficiency of the SPE procedure was evaluated using real food samples. The quantities of prometryn, linuron, metalaxyl, and metamitron determined were in the ranges of 0.02–2.24 μg/g (n = 24), 0.08–1.01 μg/g (n = 9), 1.61–2.28 μg/g (n = 4), and 0.05–1.07 μg/g (n = 3), respectively, in plant material sampled in 2011. The method was validated for precision, repeatability, and accuracy.


Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 321
Author(s):  
Maria Orfanoudaki ◽  
Anja Hartmann ◽  
Julia Mayr ◽  
Félix L. Figueroa ◽  
Julia Vega ◽  
...  

This study presents the validation of a high-performance liquid chromatography diode array detector (HPLC-DAD) method for the determination of different mycosporine-like amino acids (MAAs) in the red alga Bostrychia scorpioides. The investigated MAAs, named bostrychines, have only been found in this specific species so far. The developed HPLC-DAD method was successfully applied for the quantification of the major MAAs in Bostrychia scorpioides extracts, collected from four different countries in Europe showing only minor differences between the investigated samples. In the past, several Bostrychia spp. have been reported to include cryptic species, and in some cases such as B. calliptera, B. simpliciuscula, and B. moritziana, the polyphyly was supported by differences in their MAA composition. The uniformity in the MAA composition of the investigated B. scorpioides samples is in agreement with the reported monophyly of this Bostrychia sp.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Thiyagarajan Sathishkumar ◽  
Ramakrishnan Baskar ◽  
Mohan Aravind ◽  
Suryanarayanan Tilak ◽  
Sri Deepthi ◽  
...  

Flavonoids are exploited as antioxidants, antimicrobial, antithrombogenic, antiviral, and antihypercholesterolemic agents. Normally, conventional extraction techniques like soxhlet or shake flask methods provide low yield of flavonoids with structural loss, and thereby, these techniques may be considered as inefficient. In this regard, an attempt was made to optimize the flavonoid extraction using orthogonal design of experiment and subsequent structural elucidation by high-performance liquid chromatography-diode array detector-electron spray ionization/mass spectrometry (HPLC-DAD-ESI/MS) techniques. The shake flask method of flavonoid extraction was observed to provide a yield of 1.2±0.13 (mg/g tissue). With the two different solvents, namely, ethanol and ethyl acetate, tried for the extraction optimization of flavonoid, ethanol (80.1 mg/g tissue) has been proved better than ethyl acetate (20.5 mg/g tissue). The optimal conditions of the extraction of flavonoid were found to be 85°C, 3 hours with a material ratio of 1 : 20, 75% ethanol, and 1 cycle of extraction. About seven different phenolics like robinin, quercetin, rutin, sinapoyl-hexoside, dicaffeic acid, and two unknown compounds were identified for the first time in the flowers of T. heyneana. The study has also concluded that L16 orthogonal design of experiment is an effective method for the extraction of flavonoid than the shake flask method.


Author(s):  
M. F. Zayats ◽  
S. M. Leschev

Based on the distribution constants of biphenazate, obtained experimentally and also calculated from literature data on the solubility of biphenazate in water and organic solvents, as well as experimental data on the extraction of biphenazate from plant matrices by various extractants, we selected the optimal conditions for extracting biphenazate from apples and cucumbers. The conditions for the purification of the extracts were also selected. Acetonitrile in the presence of ammonium sulfate and hexane was used for extraction of the pesticide. Purification of extracts of plant materials was carried out by partitioning between hexane and water-acetonitrile mixture. The samples obtained after this treatment were pure enough to determine the residual amounts of biphenazate in them at the maximum residue level determined in Belarus and the countries of the European Union, or lower using widespread liquid chromatography with diode-array (ultraviolet) detection.


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