Name: capillary electrophoresis for fast separations
Uploaded: 2023-04-30T06:47:21.000Z
Duration: 8 min 50 s
Channel: JoVE

K12 Standards

new-york-state-science-learning-standards

New York State Science Learning Standards

High School

Physical Science

HS. Structure and Properties of Matter

HS-PS1-10.

Capillary Electrophoresis (CE)

1. CE Instrumentation Setup
<ol>
	<li>Turn on the CE instrument and computer. Using the computer software, turn on the light source for UV analysis to allow it to warm up. Some software has an indicator when the lamp is ready for use (lamp icon turns color).</li>
	<li>Make a methods file. Set the important parameters for running the CE. In this analysis the temperatures of the cartridge and sample storage are 35 &#176;C. The wavelength&#160;for UV detection is 214 nm.</li>
	<li>Write a time program. The program generally consists of rinse steps (to clean the capillary before analysis), injection steps, and then an electrophoresis step. For the rinse step, perform 2 rinses for 1 min using 20 psi of pressure. The first rinse is with NaOH, which helps make sure the silanol groups on the capillary wall are deprotonated. The second rinse is with run buffer (0.025 M borate buffer here) to make sure the capillary is left equilibrated with buffer.</li>
	<li>For the injection, pressure injection is used at 0.5 psi for 5 s.</li>
	<li>For the electrophoresis step, the conditions are separation voltage: 20 kV, time: 5 min, normal polarity. For each step, also indicate which vial is the inlet and which vial is the outlet. Save the methods file after all the parameters are entered.</li>
</ol>
2. Preparation of the Standards and Soda Samples
<ol>
	<li>Make 500-ppm stock solutions of aspartame, caffeine, and benzoic acid in water. Make 50 mL of each, using a volumetric flask.</li>
	<li>Make a standard solution of 150 ppm aspartame, 150 ppm caffeine, and 100 ppm benzoic acid in a 10-mL volumetric flask.</li>
	<li>Make standard caffeine solutions of 50 ppm, 100 ppm, 150 ppm, and 200 ppm in a 10-mL volumetric flasks.</li>
</ol>
3. Run the Samples on the CE
<ol>
	<li>Place the vials containing either standards or soda samples into the sample vial holder. Make sure to write down which sample is in which slot. Two slots have the borate run buffer and the 0.1 M NaOH rinse solution.</li>
	<li>In the method file, input which slot the first sample vial is in.</li>
	<li>Acquire a single run, making sure to input all the data information the program requests.</li>
	<li>Continue to acquire data, changing the input vial for each sample. Run the combination standard, the 3 concentrations of caffeine, and a Pepsi and diet Pepsi sample.</li>
	<li>Insert the target into the instrument and choose the appropriate instrument.</li>
	<li>Analyze the data on the computer. Calculate the peak areas and overlay standards and real samples to help identify peaks. Make a calibration curve for the caffeine data.</li>
</ol>

Capillary electrophoresis is used for many specialty separations. For example, it is used in the pharmaceutical industry for quality testing, to make sure there are no side products or interferents. CE is particularly useful for separating drugs with a basic amino group, as the walls of the capillary can be made neutral with an acidic pH and thus the drug will not stick to the capillary.
A mode of CE was also used to sequence the human genome and separate DNA. This mode of CE is capillary gel ...

capillary electrophoresis (ce)

Source: Laboratory of Dr. B. Jill Venton - University of Virginia
Capillary electrophoresis (CE) is a separation technique that separates molecules in an electric field according to size and charge. CE is performed in a small glass tube called a capillary that is filled with an electrolyte solution. Analytes are separated due to differences in electrophoretic mobility, which varies with charge, solvent viscosity, and size. Traditional electrophoresis in gels is limited in the amount of voltage that can be applied because Joule heating effects will ruin the gel and the separation. Capillaries have a large surface area-to-volume ratio and thus dissipate heat better. Therefore, the voltages applied for a capillary electrophoresis experiment are quite large, often 10,000&#8211;20,000 V.
Capillary electrophoresis is useful for high-performance separations. Compared to liquid chromatography, CE separations are often faster and more efficient. However, capillary electrophoresis works best to separate charged molecules, which is not a limitation of liquid chromatography. CE has a greater peak capacity than high-performance liquid chromatography (HPLC), meaning the separations are more efficient and more peaks can be detected. The instrumentation can be very simple. However, HPLC is more versatile and many stationary and mobile phases have been developed for different types of molecules.

Electropherograms collected for diet Pepsi and Pepsi samples are shown in Figures 1 and 2, respectively. The three peaks for caffeine, aspartame, and benzoic acid are observed in diet Pepsi and have similar migration times as the standards. For regular Pepsi, the caffeine peak is present but not the aspartame and benzoic acid peaks. The CE analysis is fast as the migration times are only 3–4 min.
The calibration curve for caffeine is shown in Figure 3<...

Source: Laboratory of Dr. B. Jill Venton - University of Virginia
Capillary electrophoresis (CE) is a separation technique that separates molecules in an ...

Capillary electrophoresis, or CE, is a technique used in chemical analysis to separate molecules in an electric field according to size and charge.Capillary Electrophoresis is performed in a sub-millimeter diameter tube, called a capillary, which contains a flowing electrolyte solution. The sample is injected into the capillary, and an electric field is applied. The molecules are then separated based on the difference in their velocity, which is influenced by charge, size, and the solvent's viscosity. CE is ideal for the separation of charged molecules and has a greater resolution than high-performance liquid chromatography, making it more efficient and sensitive.This video will introduce the basics of capillary electrophoresis and demonstrate its use by determining the composition of a soft drink.In CE, an electric field is applied to a capillary filled with an electrolyte. The electric field induces a positive charge at the capillary inlet, and a negative charge at the outlet.The electrolyte flows within the capillary, induced by the electric field. This flow, called electro-osmotic flow, is caused by the movement of a discrete layer of positively-charged salt ions along the nega

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Analytical Chemistry

capillary electrophoresis for fast separations

Capillary electrophoresis is a separation method that uses an electric field to sort molecules by size and charge. It is carried out in a small glass tube called a capillary. The capillary is filled with an electrolyte solution, which helps the analytes move during the separation.

Molecules separate because they have different electrophoretic mobility, or different speeds in the electric field. That mobility depends on charge, solvent viscosity, and size. Because the capillary has a large surface area-to-volume ratio, it removes heat more effectively than a gel.

Traditional gel electrophoresis cannot use very high voltage because Joule heating can damage the gel and ruin the separation. Capillary electrophoresis avoids that problem better and can use much higher voltages, often 10,000 to 20,000 V. This makes it useful for high-performance separations.

Compared with liquid chromatography, capillary electrophoresis is often faster and more efficient. It also has a greater peak capacity than high-performance liquid chromatography, or HPLC, so more peaks can be detected. CE works best for charged molecules, while HPLC is more versatile and uses many stationary and mobile phases for different kinds of molecules. The instrumentation for CE can also be very simple.

Capillary Electrophoresis for Fast Separations

capillary-electrophoresis-for-fast-separations

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Capillary electrophoresis is a separation method that uses an electric field to sort molecules by size and charge. It is carried out in a small glass tube called a capillary. The capillary is filled with an electrolyte solution, which helps the analytes move during the separation. Molecules separate because they have different electrophoretic mobility, or different speeds in the electric field. That mobility depends on charge, solvent viscosity, and size. Because the capillary has a large...

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analytical chemistry

This collection takes a broad look at quantitative analysis and instrumentation including electrochemistry, spectroscopy, chromatography, and mass spectrometry.

Learn how capillary electrophoresis uses a glass capillary and high voltage to separate charged molecules quickly by size and charge.

Capillary Electrophoresis for Fast Separations | JoVE K12

Barbara Jill Venton

University of Virginia

Overview

Principles of Capillary Electrophoresis

CE Instrumentation Setup

Preparation of the Standards and Soda Samples

Running the Samples

Applications

Summary

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Capillary Electrophoresis for Fast Separations

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