Development of a Special Two-Dimensional Fingerprint for the Quality Evaluation of Euonymus Alatu by HPLC with Diode Array Detector Coupled with Chemiluminescence Detection

A special two-dimensional fingerprint developed by a hyphenated method, HPLC–DAD coupled with flow injection analysis and chemiluminescence detection (HPLC–DAD–FIA–CL), was applied to evaluate the quality of Euonymus alatu. Chromatographic fingerprint and active characteristics of Euonymus alatu from different habitats were investigated by HPLC–DAD–FIA–CL method. The similarity of two-dimensional fingerprint obtained by a vectorial angle method was used to evaluate the quality of Euonymus alatu. The results suggested that the two-dimensional fingerprint could reveal more objective conclusions for the quality of Euonymus alatu, and might be helpful to improve the quality control ability of herbal medicines.     

Investigation on sensitized chemiluminescence systems and their mechanism for five fluoroquinolones

The novel chemiluminescence (CL) reaction systems were established for lomefloxacin (LMFX), ofloxacin(OFLX), norfloxacin (NFLX), gatifloxacin (GAFX) and enoxacin (ENX). The sensitized CL emission mechanism was investigated for the five systems by comparing the fluorescence emission with CL spectra. For LMFX-Ce(IV)-S₂O₃²⁻-H₂SO₄ and OFLX-Ce(IV)-S₂O₄²⁻-H₂SO₄ systems, the CL intensity is enhanced through intermolecular energy transfer from the excited SO₂^* to LMFX and OFLX. For NFLX-Ce(IV)-S₂O₄²⁻-HNO₃ system, the sensitized CL is based on intermolecular energy transfer from the excited SO₂^* to NFLX oxide. For Eu³⁺-GAFX-Ce(IV)-S₂O₄²⁻-HCl and Dy³⁺-ENX-Ce(IV)-S₂O₃²⁻-H₂SO₄ systems, the CL spectra are from the narrow characteristic emission at 590, 619 and 649 nm of Eu^3+* (⁵D₀ → ⁷F₁, ⁵D₀ → ⁷F₂, ⁵D₀ → ⁷F₃) and at 482 and 578 nm of Dy³⁺ (⁴F₉ → ⁶H_15/2, ⁴F₉ → ⁶H_13/2) through intermolecular energy transfer from the excited SO₂^* to GAFX and ENX, followed by intramolecular energy transfer from GAFX^* to Eu³⁺ and ENX^* to Dy³⁺. The conditions of CL emission were investigated and optimized. The proposed five enhanced CL systems have good linearity, higher sensitivity, precision and potential capability for residue analysis of studied analytes in foods and biological samples.     

流动注射化学发光法测定L-乳酸铝

发现L-乳酸铝对纳米金-酸性高锰酸钾体系化学发光的增强作用,其增强化学发光强度的能力与高锰酸钾及溶液的介质硫酸浓度、金浓度以及蠕动泵的转速、流动注射化学反应体系的流路设计等因素有关,在此基础上首次建立了测定L-乳酸铝的增强化学发光分析法。测定L-乳酸铝的线性范围为7.0×10-5～1.0×10-2g.mL-1,检出限为1.04×10-6g.mL-1(S/N=3),对8.0×10-4g.mL-1的L-乳酸铝标准溶液进行11次平行测定,相对标准偏差(RSD)为1.48%。该法直接用于L-乳酸铝制备合成反应液以及分离纯化废液中L-乳酸铝的测定,其回收率为95.8%～100.4%,本法与GB/T6987.8-2001法进行了对照,结果令人满意。探讨了该化学发光增强作用是由于L-乳酸铝注入体系后,加速了纳米金与酸性高锰酸钾的反应所致。     

化学发光法测定巯嘌呤的含量

在流动注射系统中,利用巯嘌呤在碱性Luminol-K₃Fe(CN)₆化学发光体系中发光信号强的特点,建立了一种测定巯嘌呤的新方法。在优化条件下,方法的线性范围是1.02×10-7～1.02×10-9mol·L-1, 回归方程是Y=36.315c+140.72(Y是相对发光强度,c是巯嘌呤浓度与10-8 mol·L-1的乘积), 相关系数是0.998 2,检出限(S/N=3)是6.33×10-10mol·L-1,RSD为3.54%（c_i=2.0×10-9mol·L-1, n=12）。该法用于合成样品的测定,简便、灵敏、快速,结果令人满意。文章简要地探讨了巯嘌呤在碱性Luminol-K₃Fe(CN)₆化学发光体系中的化学发光机理：在反应过程中,产生大量的过氧自由基和羟基自由基,自由基与鲁米诺反应,形成激发态的鲁米诺分子,鲁米诺分子由激发态回到基态产生化学发光现象。