A solid phase extraction technique for the determination of platinum(IV) at trace levels by inductively coupled plasma mass spectromA solid phase extraction technique for the determination of platinum(IV) at trace levels by inductively coupled plasma mass spectrometry (ICP-MS) was developed. The method was based on retention of platinum in a sample on silica gel modified with aminepropyl groups. The retention of platinum(IV) from the sample solution and the recovery of platinum with 1.0 mol L−1 thiourea solution were quantitative. The relative standard deviation (RSD) was calculated as 5% (n = 7) at the 10 ng L−1 level. The enrichment factor was found to be (50-fold) for 250 mL of water sample. Under optimum conditions, the method detection limit (MDL) was found to be 1 ng L−1 for platinum in water matrices. Recoveries of Pt from spike addition to atmospheric water samples were quantitative (80–95%). The present method was used for the determination of platinum in precipitation, throughfall and runoff water samples. [...]
Solid-phase extraction (SPE) is simple and inexpensive sample preparation procedure which can be applied for the isolation/fractionation of essential oil compounds from wide variety of samples, such as foodstuffs, biological and environmental. Due to the complex nature of the examined matrices and frequently low concentration level of target components, analytical procedures require the use of initial sample preparation stage. The paper shows the possibility of essential oil components fractionation from different plant materials using SPE method. The results presented in this paper shows that the proposed SPE procedure allows for easy and total fractionation of essential oil constituents (especially low-molecular oxygen compounds) from the sample matrix.
The development of a biosensor based on the immobilization of horseradish peroxidase (HRP) within a zirconium alkoxide-polyetilenimine film onto screen-printed electrodes (SPE) for acetaminophen detection and acetaminophen quantification in pharmaceutical products is described. The biosensor operation mode is based on monitoring the amperometric signal produced by the electrochemical reduction of the enzymatically generated electroactive oxidized species of acetaminophen in the presence of hydrogen peroxide. The enzyme immobilization is performed by retention in a polyethylenimine-zirconium alcoxide porous gel film, a technique that offers good entrapping and a protective environment for the biocomponent due to the hydration properties of the immobilization layer. SPEs have the advantage of being easily mass-produced at low costs with superior characteristics in comparison with classical electrode materials. In this configuration, zirconium alkoxide demonstrates its electrocatalytic activity. The biosensor allows the quantification of acetaminophen with a limit of detection of 6.21×10−8 M and a linear range between 4.35×10−7 M and 4.98×10−6 M. Finally, the biosensor is applied to the quantitative analysis of acetaminophen in Perdolan® tablets. [...]
Rutin is a flavonoid commonly employed for many therapeutic purposes. Although the electroactive phenolic groups of rutin might be oxidized at low applied potential, the adsorption of oxidized species changes the electrode surface. As a consequence, the repeatability and reproducibility of the method decreases, which limits electroanalytical applications. This paper describes the use of disposable screen-printed electrodes as an alternative to improve the electrochemical quantification of rutin in commercial and standard samples. The electrochemical behavior was consistent to what is observed using other carbon electrodes: an adsorption-involved step and a pH-dependent oxidation process. The replacement of the electrodes between the analyses ensured rapid analysis, good intermediate precision and repeatability. The proposed method was successfully applied to rutin determination in pharmaceutical samples of capsules, with the limit of quantification being 0.30 µM. [...]
Determination of non-steroidal anti-infl ammatory drugs (NSAIDs) in human and animal physiological fl uids requires the use of appropriate pro-cedures permitting rapid and effi cient recovery of the drugs from biological matrices. The aim of this study was to compare various methods of NSAIDs extraction from human serum that is essential for GC/MS analysis of the drugs. Commercially available biochemistry control human serum supplemented with ibuprofen, paracetamol, fl urbiprofen, nabumeton, naproxen, ketoprofen, mefenamic acid and diclofenac sodium salt was used. Solid phase extraction, HybridSPE- -PPT technology and liquid-liquid extraction were applied for NSAIDs isolation from the serum. GC/MS analysis of the drugs was preceded by their derivatization to trimethylsilyl esters with BSTFA. The highest extraction effi ciency and the best separation of the drugs from endogenous components of the serum were achieved using the solid phase extraction on octadecyl-bonded silica.
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Oznaczanie niesteroidowych leków przeciwzapalnych (NLPZ) w płynach fizjologicznych ludzi i zwierząt wymaga zastosowania szybkich i wydajnych procedur izolacji tych leków z biologicznej matrycy. Celem pracy było porównanie różnych metod ekstrakcji NLPZ z surowicy ludzkiej, jako etapu poprzedzającego analizę tych leków techniką GC/MS. W badaniach wykorzystano dostępną handlowo surowicę stosowaną jako materiał kontrolny w oznaczeniach biochemicznych, do której dodano ibuprofen, paracetamol, flurbiprofen, nabumeton, naproksen, ketoprofen, kwas mefenamowy oraz sól sodową diklofenaku. W celu wyizolowania NLPZ z surowicy zastosowano ekstrakcję do fazy stałej, technikę HybridSPE- -PPT oraz ekstrakcję ciecz-ciecz. Leki poddano derywatyzacji do pochodnych trimetylosililowych za pomocą BSTFA, a następnie analizowano techniką GC/MS. Najwyższą wydajność ekstrakcji oraz najlepszy stopień oddzielenia NLPZ od endogennych składników surowicy uzyskano metodą ekstrakcji do fazy stałej w postaci żelu krzemionkowego z aktywnymi grupami oktadecylowymi.
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