Development of a packed-column supercritical fluid chromatography/atmospheric pressure chemical-ionisation mass spectrometric technique for the analysis of atropine

Determination of Atropine Sulfate in Human Urines by Capillary Electrophoresis Using Chemical Modified Electrode as Electrochemiluminescence Sensor

A Ru(bpy)3 2+-based electrochemiluminescence (ECL) detection coupled with capillary electrophoresis (CE) was developed for the determination of atropine sulfate on the basis of an Eu-PB modified platinum electrode as the working electrode. The analyte was injected to separation capillary of 50 cm length (25 μm i.d., 360 μm o.d.) by electrokinetic injection for 10 s at 10 kV. Parameters related to the separation and detection were discussed and optimized. It was proved that 10 mM phosphate buffer at pH 8.0 could achieve the most favorable resolution, and the high sensitivity of detection was obtained by using the detection potential at 1.15 V and 5 mM Ru(bpy)3 2+in 80 mM phosphate buffer at pH 8.0 in the detection reservoir. Under the optimized conditions, the ECL peak area was in proportion to atropine sulfate concentration in the range from 0.08 to 20 μg⋅mL−1with a detection limit of 50 ng⋅mL−1(3σ). The relative standard derivations of migration time and peak area were 0.81 and 3.19%, respectively. The developed method was successfully applied to determine the levels of atropine sulfate in urine samples of patients with recoveries between 90.9 and 98.6%.

Bioanalytical applications using supercritical fluid techniques

The bioanalytical applications of supercritical fluid techniques, such as supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC), are of increasing interest. The main role of these techniques is in the sample preparation and separation of biologically active compounds, particularly drugs and their metabolites, as well as endogenous compounds. An insight is given into the different types of extracting fluids and modifiers, detectors, stationary phases, mobile phases and collection strategies. A critical discussion is presented on the existing state of the art concerning the applications of SFC and SFE with a specific focus on its advantages and limitations in the bioanalytical field. New developments and the possibilities for routine work in the near future are also covered.

Advantages and drawbacks of popular supercritical fluid chromatography/mass interfacing approaches--a user's perspective

Mobile phases in supercritical fluid chromatography (SFC) have low viscosities and high diffusion coefficients with respect to those of traditional high performance liquid chromatography (HPLC). These properties allow higher mobile phase flow rates and/or longer columns in SFC, resulting in rapid analyses and high efficiency separations. In addition, chiral SFC is becoming especially popular. Mass spectrometry (MS) is arguably the most popular "informative" detector for chromatographic separations. Most SFC/MS is performed with atmospheric pressure ionization (API) sources. Unlike LC/MS, the interface between the SFC column and the API source must allow control of the downstream (post-column) pressure while also providing good chromatographic fidelity. Here we compare and contrast the popular interfacing approaches. Some are simple, such as direct effluent introduction with no active back-pressure-regulator (BPR) in high speed bioanalytical applications. The pressure-regulating-fluid interface is more versatile and provides excellent chromatographic fidelity, but is less user friendly. The pre-BPR- split interface and an interface which provides total-flow-introduction with a mechanical BPR are good compromises between user friendliness and performance, and have become the most popular among practitioners. Applications of SFC/MS using these various interfaces are also discussed.

Analysis of tropane and related alkaloids

The current methods for tropane alkaloid chromatographic separation and determination are summarised. The alkaloids included are: the medicinally applied tropic acid esters hyoscyamine and scopolamine and their derivatives, cocaine and derivatives, the metabolites and degradation products of these compounds occurring in plant material, calystegines as nortropane alkaloids, anatoxins as homonortropane alkaloids, pelletierines and pseudopelletierines as alkaloids with isomeric structures. Developments in GC, HPLC, CE and TLC are presented and the advantages of each method for plant analysis are discussed. A summary for each chromatographic method lists the instrumentation and parameters applied for tropane alkaloids.