In this paper, we describe a compact and low-cost light-emitting diode-induced fluorescence (LED-IF) detection coupled to microchip electrophoresis for the determination of sulfonamides in pharmaceutical formulations and rabbit plasma. Three fluorescein isothiocyanate-labeled sulfonamides in rabbit plasma were separated in the running buffer of 40 mM phosphate buffer (pH 7.0) at the separation voltage of 2.0 kV, and detected by LED-IF detector in which the high-power blue LED was driven at the constant current of 150 mA and the emitted fluorescence over 510 nm was collected by a planar photodiode. The linear concentration ranged from 2.0 to 125.0 μg mL−1, both for sulfadiazine and sulfamethazine with the correlation coefficients (r2) of 0.995 and 0.997, respectively, and from 2.0 to 100.0 μg mL−1 with the correlation coefficients (r2) of 0.997 for sulfaguanidine. The limits of detection for the three sulfonamides were 0.36–0.50 μg mL−1 (S/N = 3). Intra-day and inter-day precision of migration time and peak area for the determination of sulfonamides were <4.5 %. This method has been successfully applied to the analysis of sulfonamides in pharmaceuticals, and could be used to study the pharmacokinetics of sulfonamides in rabbit.
Recently, the frequency of combining MXene, which has unique properties such as metal-level conductivity and large specific surface area, with silicon to achieve excellent electrochemical performance has increased considerably. There is no doubt that the introduction of MXene can improve the conductivity of silicon and the cycling stability of electrodes after elaborate structure design. However, most exhaustive contacts can only improve the electrode conductivity on the plane. Herein, a MXene@Si/CNTs (HIEN-MSC) composite with hierarchical interpenetrating electroconductive networks has been synthesized by electrostatic self-assembly. In this process, the CNTs are first combined with silicon nanoparticles and then assembled with MXene nanosheets. Inserting CNTs into silicon nanoparticles can not only reduce the latter‘s agglomeration, but also immobilizes them on the three-dimensional conductive framework composed of CNTs and MXene nanosheets. Therefore, the HIEN-MSC electrode shows superior rate performance (high reversible capacity of 280 mA h−1 even tested at 10 A g−1), cycling stability (stable reversible capacity of 547 mA h g−1 after 200 cycles at 1 A g−1) and applicability (a high reversible capacity of 101 mA h g−1 after 50 cycles when assembled with NCM622 into a full cell). These results may provide new insights for other electrodes with excellent rate performance and long-cycle stability. 相似文献
In this paper, we give discreteness criteria of subgroups of the special linear group on Qp or Cp in two and higher dimensions. J rgensen's inequality gives a necessary condition for a nonelementary group of Mbius transformations to be discrete. We give a version of Jфrgensen's inequality for SL(m, Cp). 相似文献
The electrocatalysis of nitrate reduction reaction(NRR) has been considered to be a promising nitrate removal technology.Developing a highly effective iron-based electrocatalyst is an essential challenge for NRR.Herein,boron-iron nanochains(B-Fe NCs) as efficient NRR catalysts were prepared via a facile lowcost and scalable method.The Fe/B ratio of the B-Fe NCs-x can be elaborately adjusted to optimize the NRR catalytic performance.Due to the electron transfer from boron to metal,the metal-metal bonds are weakened and the electron density near the metal atom centers are rearranged,which are favor of the conversion from NO_3~-into N_2.Moreover,the well-crosslinked chain-like architectures benefit the mass/electron transport to boost the exposure of abundant catalytic active sites.Laboratory experiments demonstrated that the optimized B-Fe NCs catalyst exhibits superior intrinsic electrocatalytic NRR activity of high nitrate conversion(~80%),ultrahigh nitrogen selectivity(~99%) and excellent long-term reactivity in the mixed electrolyte system(0.02 mol/L NaCl and 0.02 mol/L Na_2 SO_4 mixed electrolyte),and the electrocatalytic activity of the material shows poor performance at low chloride ion concentration(Nitrate conversion of ~61 % and nitrogen selectivity of ~57% in 0.005 mol/L NaCl and 0.035 mol/L Na_2 SO_4 mixed electrolyte).This study provides a broad application prospect for further exploring the highefficiency and low-cost iron-based functional nanostructures for electrocatalytic nitrate reduction. 相似文献