Multi-walled carbon nanotube multilayers were modified onto a newly proposed gold hair microelectrode via a simple layer-by-layer assembling method.The resulting electrode showed a sensitive oxidation response to estradiol with detection limit as low as 1.0×10^(-8) mol/L,foreseeing a promising approach to the fabrication of high-sensitive microsensors.
A new liquid chromatography-mass spectrometry method for the determination of carbamazepine,clonazepam,alprazolam,estazolam and phenytoin in human plasma has been developed by using diazepam as an internal standard.Chromatographic separation was performed on a Zorbax SB-C18 column(30 mm × 2.1 mm,3.5 ?m) with a mobile phase consisting of methanol and aqueous 25 mM ammonium acetate using gradient elution.A diethyl ether extraction method was used for the extraction of five anti-epilepsy drugs.The final extract was injected for analysis by LC-MS/MS.The method was validated within the concentration range of 50-5000 ng mL-1 for five anti-epilepsy drugs.The precision of the assay(RSD%) was less than 10% at all concentration levels within the tested range.The method recoveries for all samples were more than 90%.The results indicate that the method is specific,sensitive and accurate,and suitable to study the pharmacokinetics,to adjust the dosage for individual administration,and to monitor the drug-concentration and drug abuse of the five anti-epilepsy drugs.
In this work,the electrochemical behavior of methyl jasmonate(MeJA)on a glassy carbon electrode was investigated in 0.1 mol/L H2SO4 by voltammetry.MeJA exhibited enhanced oxidation behavior in the presence of sodium dodecyl sulfate(SDS). The electrochemical reaction of MeJA on the electrode was carried out with SDS micelles to improve the solubility of MeJA by hydrophobic interaction.Consequently,the oxidation peak current was sensitively enhanced.The effect of experimental parameters on the oxidative peak current was investigated including the surfactant concentration,supporting electrolyte,accumulation potential and time,and scan rate.
