Determination of tocopherols and sterols in vegetable oils by solid-phase extraction and subsequent capillary gas chromatographic analysis

1999 ◽  
Vol 857 (1-2) ◽  
pp. 231-238 ◽  
Author(s):  
Marion Lechner ◽  
Birgit Reiter ◽  
Eberhard Lorbeer
Toxins ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 621 ◽  
Author(s):  
Li Yu ◽  
Fei Ma ◽  
Liangxiao Zhang ◽  
Peiwu Li

In this study, magnetic graphene nanocomposite Fe3O4/rGO was synthesized by facile one-pot solvothermal method. The nanocomposite was successfully used as magnetic solid phase extraction (MSPE) adsorbents for the determination of aflatoxins in edible vegetable oils through the π–π stacking interactions. MSPE parameters including the amount of adsorbents, extraction and desorption time, washing conditions, and the type and volume of desorption solvent were optimized. Under optimal conditions, good linear relationships were achieved. Limits of detection of this method were as low as 0.02 µg/kg and 0.01 µg/kg for aflatoxin B1 and B2, respectively. Finally, the magnetic graphene nanocomposite was successfully applied to aflatoxin analysis in vegetable oils. The results indicated that the recoveries of the B-group aflatoxins ranged from 80.4% to 106.0%, whereas the relative standard deviations (RSDs) were less than 8.1%. Owing to the simplicity, rapidity and efficiency, Fe3O4/rGO magnetic solid phase extraction coupled with high-performance liquid chromatography fluorescence with post-column photochemical derivatization (Fe3O4/rGO MSPE-HPLC-PCD-FLD) is a promising analytical method for routine and accurate determination of aflatoxins in lipid matrices.


2001 ◽  
Vol 73 (1) ◽  
pp. 119-124 ◽  
Author(s):  
Lolita Liberatore ◽  
Giuseppe Procida ◽  
Nicola d'Alessandro ◽  
Angelo Cichelli

2012 ◽  
Vol 35 (21) ◽  
pp. 2932-2939 ◽  
Author(s):  
PingGu Wu ◽  
DaJin Yang ◽  
Liqun Zhang ◽  
XiangHong Shen ◽  
XiaoDong Pan ◽  
...  

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2946 ◽  
Author(s):  
Ewelina Dziurkowska ◽  
Marek Wesolowski

Saliva is far less popular as a diagnostic material than blood. This has resulted in a lack of procedures for the sampling and handling of saliva, e.g., effective ways to purify endogenous compounds from saliva to enable a simultaneous determination of xenobiotics such as neuroleptics. Therefore, the aim of this study was to develop an analytical procedure to purify saliva samples so that it is then possible to simultaneously determine five neuroleptics (aripiprazole, clozapine, olanzapine, quetiapine and risperidone) and the antiepileptic drug carbamazepine, and their respective metabolites (dehydroaripiprazole, N-desmethylclozapine, N-demethylolanzapine, norquetiapine, 9-OH-risperidone and carbamazepine-10,11-epoxide). A study of three types of solid-phase extraction (SPE) columns showed that the purest eluates were obtained using columns containing ion exchange sorbent. The sorbents were first washed with water then with a mixture of water and methanol (1:1), and the adsorbed residue was eluted with a 5% ammonia solution in methanol. Saliva samples for SPE were diluted with 2% formic acid and a mixture of methanol and water (1:1). This procedure was developed to purify a saliva sample spiked with a mixture of neuroleptics and carbamazepine, and their respective metabolites. A chromatographic analysis confirmed the isolation of all compounds, indicating that this procedure can be used in further development and validation for a method designed to monitor the levels of neuroleptic drugs in saliva and to monitor their uptake by patients.


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