What is the connection type of column?
Q22. What is the connection type?
COSMOSIL, COSMOGEL and COSMOCORE use Waters-type connectors. COSMOCORE
uses the WatersR UHPLC connector, and COSMOSIL and COSMOGEL use the conventional
Waters HPLC connector.
Waters-type connectors can be connected to most instruments, but please confirm with the manufacturer before using.
Q23. Which detection methods should I use?
Selection of a detector depends on the sample and the purpose of the experiment.
| Detector | Feature | |
|---|---|---|
| Ultraviolet-Visible (UV-Vis) Detector | [Detection] Absorbance [Sample] High sensitivity for compounds that have UV absorbance. Cannot be used for compounds that do not have UV absorbance. [Features] Easy, widely used |
|
| Fluorescence Detector (FLD) | [Detection] Fluorescence [Sample] Fluorescent samples [Features] For samples that have little or no UV absorbance. High detection sensitivity enables trace component analysis. |
|
| Refractive Index (RI) Detector | [Detection] Difference in index of refraction between sample and mobile phase [Sample] All samples [Features] For samples that have little or no UV absorbance (e.g., saccharides, alcohols, amino acids). Its disadvantages include sensitivity to change in temperature, mobile phase and flow rate. |
|
| Electrochemical Detector (ECD) | [Detection] Electrochemically active compounds | |
| Evaporative Light Scattering Detector (ELSD) | [Detection] Scattered light of particulated target compound after evaporating mobile phase [Sample] Samples that have little or no UV absorbance (e.g., saccharides, alcohols, amino acids). [Features] High versatility, but not compatible with low-boiling compounds. |
|
| Mass Spectrometric (MS) Detector | [Features] Can acquire MS data for separated components for qualitative analysis. Compatible mobile phases are limited. | |
Q24. What is the common pressure unit?
The most common unit of pressure is the SI unit, MPa.
Old instruments sometimes have different units (conversion: 1 MPa = 10.197
kgf/cm2= 145.0 psi = 10 bar).
Q25. What is dead volume?
Dead volume is the flow path volume from injector to detector that does not contribute to separation. If dead volume is large, sample may spread and have poor peak shape. Choose proper injector, detector cell, tubing, and column inner diameter to minimize dead volume. For appropriate inner diameters of tubing and detector cells, refer to Technical Information , Scale Up and Scale Down (PDF 878 KB)
