Dionex Model 4500i Ion Chromatograph
Overview -
The Dionex 4500i Ion Chromatograph (IC) is used to separate and quanitfy ionic species in a liquid matrix.
Theory -
the ic is a form of chromaograaphy employing a liquid mobile phase and effecing a separation of ionic species. either conductivity, amperometry/coulometry, or UV-Vis spectroscopy may be used to detect the resolved species.
Based on some physical property, typically charge density, the componenets interact with the column to varying degrees. Species which don't interact with the column at all will flow through the column at the same speed as the eluant. Other species will interact with the column to varying degrees, and thus will travel through the column at different rates. By traveling through the column at different rates, the componenets of the sample are separated from one another.
The make-up of the column, column temperature, eluant flow rate, and the composition of the eluant all play a part in effecting the separation. While the actual analytical time may be short, a lot of research effort can go into determining the best conditions for separating the components of a sample.
Methods -
Microwave digestion of media
Microwave digestion of filter paper
Detection Limits -
Several types of detectors. including UV, conductivity, coulometric, and amperametric, may be with the ion chromatographic separation. For most techniques and conditions, detection limits of mid to high parts-per-billion are typical.
Sample Matrix -
The sample must be in a liquid matrix. While some work has been done with organic solvents, for the most part, IC analysis are perfomred on aqueous samples.
Sample Size -
The usual sample volume is 50-100 uL per replicate analysis, but the sample vial needs to be loaded with 250-100 uL for the sampling needle to reliably draw up the sample.
Approximate C0st -
Neglecting the cost of sample preparation, the cost of the instrument is $XX.XX/hour.