RESUMEN
The aim of this study was to develop a method for the separation of oxaliplatin enantiomers at attomolar concentration levels. A combination of capillary electrophoresis and inductively coupled plasma mass spectrometry was chosen due to their unique characteristics, including fast and easy modification of separation selectivity, and significant limits of detection and linearity. In the first step, we optimized conditions for the separation of oxaliplatin enantiomers including background electrolyte composition and concentration, pH, and type and concentration of the chiral selector. Under optimal conditions, sodium borate buffer pH 9.5, ionic strength 40â¯mmolâ¯L-1, with 60â¯mgâ¯mL-1 sulfated ß-cyclodextrin, separation was obtained with a resolution of 2.0. This electrolyte system was then used in the 'in-house' connection of capillary electrophoresis with inductively coupled plasma mass spectrometer. In this instance, separation lasted for 9.5â¯min. Calibrations were linear in the range of 0.1-500⯵gâ¯mL-1 with R2 of 0.9999. LOD and LOQ values were of 64â¯ngâ¯mL-1 and 116â¯ngâ¯mL-1 of oxaliplatin, respectively. This represents detection of 49â¯fg or 125 attomol of oxaliplatin enantiomers in the capillary electrophoresis injected sample zone. Finally, the method was successfully applied for detection of oxaliplatin enantiomers in spiked urine samples.
Asunto(s)
Electroforesis Capilar/métodos , Límite de Detección , Espectrometría de Masas/métodos , Oxaliplatino/análisis , Oxaliplatino/química , Gases em Plasma/química , Oxaliplatino/aislamiento & purificación , EstereoisomerismoRESUMEN
The combination of capillaries with different internal diameters was used to accelerate the separation of enantiomers in capillary electrophoresis. Separation of R,S-1,1'-binaphthalene-2,2'-diyl hydrogen phosphate using isopropyl derivative of cyclofructan 6 was studied as a model system. The best separation conditions included 500 mM sodium borate pH 9.5 with 60 mM concentration of the chiral selector. Separation lasted approx. 1.5 min using the combination of 50 and 100 µm id capillaries of 9.7 cm and 22.9 cm, respectively. It allowed approx. 12-fold acceleration in comparison to the traditional long-end separation mainly due to the higher electroosmotic flow generated in the connected capillaries.
Asunto(s)
Electroforesis Capilar/instrumentación , Electroforesis Capilar/métodos , Fructanos/química , Modelos Químicos , Naftalenos/química , Reproducibilidad de los Resultados , EstereoisomerismoRESUMEN
In our work, we introduced a novel concept of the lab-in-a-syringe tests. We solved the problem of detection in already published LIS tests by putting all the reaction and detection pads directly into the syringe barrel. We also used more layers to make the results visible for users. Two detection layouts: (i) with using rounded pads-based detection, and (ii) with using rectangular detection pads, were studied. As the proof of concept, we studied the determination of Ni(II) using dimethylglyoxime as the reagent and blocking of the interference of Fe(II). The calibrations for Ni(II) at the optimal conditions has excellent R2 of 0.998 with production costs of 0.2 USD per one test.