Identification of ionic liquid components by RP-HPLC with diode array detector using chaotropic effect and perturbation technique

2012 ◽  
Vol 35 (2) ◽  
pp. 248-255 ◽  
Author(s):  
Jolanta Flieger ◽  
Anna Czajkowska-Żelazko
Author(s):  
Maria Paola Melis ◽  
Elisabetta Angioni ◽  
Gianfranca Carta ◽  
Elisabetta Murru ◽  
Paolo Scanu ◽  
...  

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.


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.


2013 ◽  
Vol 49 (2) ◽  
pp. 301-309 ◽  
Author(s):  
Syed Naeem Razzaq ◽  
Muhammad Ashfaq ◽  
Irfana Mariam ◽  
Islam Ullah Khan ◽  
Syed Saleem Razzaq

The present study describes the development and subsequent validation of simple and accurate stability indicating RP-HPLC method for the determination of sparfloxacin and dexamethasone in pharmaceutical formulations in the presence of their stress-induced degradation products. Both the drugs and their stress-induced degradation products were separated within 10 minutes using C8 column and mixture of methanol and 0.02 M phosphate buffer pH 3.0 (60:40 v/v, respectively) as mobile phase at 270 nm using diode array detector. Regression analysis showed linearity in the range of 15-105 µg/mL for sparfloxacin and 5-35 µg/mL for dexamethasone. All the analytes were adequately resolved with acceptable tailing. Peak purity of the two drugs was also greater than 0.9999, showing no co-elution peaks. The developed method was applied for simultaneous determination of sparfloxacin and dexamethasone in pharmaceutical formulations for stability studies.


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.


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4137
Author(s):  
Muhammad Afiq Ngadni ◽  
Muhammad Tayyab Akhtar ◽  
Intan Safinar Ismail ◽  
Anis Irfan Norazhar ◽  
Soo Yee Lee ◽  
...  

Clitorea ternatea has been used in Ayurvedic medicine as a brain stimulant to treat mental illnesses and mental functional disorders. In this study, the metabolite profiles of crude C. ternatea root extract (CTRE), ethyl acetate (EA), and 50% aqueous methanol (50% MeOH) fractions were investigated using ultrahigh-performance liquid chromatography–diode array detector–tandem mass spectrometry (UHPLC–DAD–MS/MS), while their effect on the stress-like behavior of zebrafish, pharmacologically induced with reserpine, was investigated. A total of 32 compounds were putatively identified, among which, a series of norneolignans, clitorienolactones, and various flavonoids (flavone, flavonol, isoflavone, and isoflavanone) was found to comprise the major constituents, particularly in the EA and 50% MeOH fractions. The clitorienolactones, presently unique to the species, were present in both the free and glycosylated forms in the roots. Both the EA and 50% MeOH fractions displayed moderate effects on the stress-induced zebrafish model, significantly decreasing freezing duration and elevating the total distance travelled and average velocity, 72 h post-treatment. The results of the present study provide further evidence that the basis for the use of C. ternatea roots in traditional medicine to alleviate brain-related conditions, such as stress and depression, is attributable to the presence of clitorienolactones and the isoflavonoidal constituents.


1986 ◽  
Vol 17 (5) ◽  
pp. 415-423 ◽  
Author(s):  
N. Everall ◽  
R. W. Jackson ◽  
J. Howard ◽  
K. Hutchinson

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