Rapid separation and detection of ephedrine-type stimulants by microchip capillary electrophoresis with laser-induced fluorescence
Rapid separation and detection of ephedrine-type stimulants by microchip capillary electrophoresis with laser-induced fluorescence
This assay is mainly used for the detection of ephedrine stimulants.
Operation method
Chip capillary electrophoresis
Principle
The experimental conditions for the separation and determination of ephedrine and pseudoephedrine derivatized by 7-chloro-4-nitrobenzo-2-oax-1,3-diazole (NBD-Cl) were investigated using a laser-induced fluorescence detection system with chip capillary electrophoresis. The rapid separation of ephedrine and pseudoephedrine was achieved using a micellar capillary electrokinetic chromatographic separation system (12 mmol/L SDS+10 mmol/L borax buffer, pH 9.0) on a 45 mm-long channel, with a single separation time of less than 1.5 min. A good linear relationship between the peak heights and the concentrations was observed in the range of 10-100 mg/L, and the limits of detection of ephedrine and pseudoephedrine were 0.83 mg/L and 0.83 mg/L, respectively. The limits of detection of ephedrine and pseudoephedrine were 0.83 mg/L and 1.10 mg/L, respectively.
Materials and Instruments
Urine Sample Move 1. Chip preparation Cross-channel glass chip preparation. The total length of the separation channel was 45 mm (effective length 38 mm), the total length of the feed channel was 10 mm, the top width of the channel was 50 μm, and the depth was 15 μm. 2. Urine sample pretreatment Take 5 mL of urine sample in a 20 mL centrifuge tube, add 2 mL of ether and 1 g of anhydrous Na2SO4, and centrifuge for 5 min after shaking. Pipette the upper organic phase in 2 mL centrifuge tube, blow dry with N2, add 100 μL of water to dissolve the residue. 3. Derivatization of the substance to be measured Pipette 100 μL of EP and PEP mixed standard solution (or the above solution) in a 2 mL centrifuge tube, add 100 μL of 100 mmol/L borax buffer (pH 8.4), 25 mmol/L NBD-Cl solution 200 μL, dilute to 1 mL with water, and then warm bath at 50 ℃ for 30 min. 4. Separation and determination The cross channel was rinsed with 0.1 mol/L NaOH, water, and running buffer solution sequentially for 20, 10, and 20 min. running buffer was added to the sample waste pool, buffer pool, and buffer waste pool of the chip, and the channel was filled with running buffer; the sample solution was added to the sample pool, and the laser beam was focused on the lower part of the separation channel of the chip at a distance of 38 mm from the cross intersection. The following procedures were used to apply voltages to the four reservoirs for the feeding and separation operations: for 30 s of feeding, 1000, 0, 830, and 1000 V were applied to the sample liquid pool, sample waste liquid pool, buffer pool, and buffer, respectively; for 120 s of separation, 2170, 2170, 2600, and 0 V were applied to the sample liquid pool, sample waste liquid pool, and buffer pool, respectively. Caveat 1. Pay attention to the selection of clamping voltage. 2. Different SDS concentrations have different effects on the separation. 3. Choose suitable pH and separation voltage. Common Problems Source: Rapid Separation and Detection of Ephedrine Stimulants by Microarray Capillary Electrophoresis with Laser-Induced Fluorescence. For more product details, please visit Aladdin Scientific website.
Ephedrine Hydrochloride Standard Pseudoephedrine Hydrochloride Standard NBD2Cl Sodium Dodecyl Sulfate PEP Standard Solution Acetonitrile
Confocal laser-induced fluorescence detection system Inverted microscope Photomultiplier tube