References for UV-Visible Spectroscopy
UV-Visible spectroscopy is probably the most widely used instrumental techniques in analytical chemistry, especially in the life sciences. As such, it is one of the most regulated, by pharmacopoeias and quality assurance bodies world-wide. Starna supplies the world’s widest range of Certified Reference Materials for the qualification of UV-Visible Spectrophotometers to help instrument users achieve compliance – with confidence.
Ideally, references should be chosen whose calibrated values “bracket” the conditions to be used for analysis.
Instrument Qualification Kits - Tools for Easier Compliance
Starna offer several Instrument Qualification Kits to assist with the qualification of a UV-Visible Spectrophotometer in the ultraviolet region of the spectrum. Kits are tailored to the requirements of Pharmacopoeias and other Quality Assurance bodies.
Absorbance ReferencesPotassium Dichromate (235-430 nm) - the most widely used reference for absorbance accuracy – accepted by all major Pharmacopoeias Nicotinic Acid (210-260 nm) – for absorbance accuracy in the far UV Deep UV Reference (190-220 nm) – qualification in the deep UV: unique to Starna Starna Green (250-650 nm) - combined absorbance/wavelength accuracy in the UV and visible Metal-on-Quartz Neutral Density Filters (250-635 nm) - durable glass filters with UV capability Neutral Density Filters (440-635nm) - glass filters with absorbances from 0.04 A to 3.5 A Combined Holmium/Neutral Density glass (360 - 640 nm) – 1 A absorbance check with wavelength calibration Combined Didymium/Neutral Density glass (430 - 890 nm) – 1 A absorbance check with wavelength calibration |
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Wavelength References
Didymium Oxide Liquid (290-870 nm) – useful peaks in the NIR Combined Holmium/Didymium Oxide Liquid (240 to 795 nm) – evenly spaced peaks over the range Holmium Oxide Glass (270-640 nm) – more robust and useful for routine checks Didymium Glass (430 - 890 nm) – more robust and useful for routine checks Starna wide-range wavelength reference (335 - 1945 nm) - 20 peaks for wavelength calibration from UV to NIR. NEW! Combined Holmium/Neutral Density glass (360 - 640 nm) – wavelength calibration with 1 A absorbance check Combined Didymium/Neutral Density glass – (430 - 890 nm) - wavelength calibration with 1 A absorbance check Rare Earth Far UV (200-300 nm) - a convenient way of qualifying spectrophotometers in the far UV. Deep UV Reference (190-220 nm) – qualification in the deep UV: unique to Starna Starna Green (250-650 nm) - wavelength and absorbance for instruments with bandwidths >5nm Samarium Oxide Liquid (230 – 560 nm) – for the commonly used region from 200 nm to 500 nm |
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Stray Light (Stray Radiant Energy) References
Stray Light Cut-off Filters – Filter Ratio Method – recommended by US Pharmacopeia |
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Resolution (Spectral Bandwidth) References
Toluene in Methanol (265 – 270 nm) - European Pharmacopoeia (EP) resolution check for Derivative Spectroscopy. Benzene vapour (230-270 nm) – resolution reference for instruments with spectral bandwidths less than 1 nm |