- You are here:
-
Home
-
Certified Reference Materials
-
Visible Spectroscopy
- Certified Reference Materials
Technique
Visible References
References for UV-Visible Spectroscopy
UV-Visible spectroscopy is one of 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 (CRMs) 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. While regulators like the Pharmacopoeias may recommend certain references, any Certified Reference Material with appropriate certified values may be used for qualification
Instrument Qualification Kits - Tools for Easier Compliance
These kits allow instrument qualification over the stated wavelength and absorbance ranges for compliance with EP 2.2.25 and USP . References are provided to qualify wavelength accuracy, absorbance accuracy and 3-point linearity, stray light and resolution/bandwidth.
Absorbance References
Potassium Dichromate (235-430 nm) - the most widely used reference for absorbance accuracy and linearity
Nicotinic Acid (210-260 nm) – recommended by Pharmacopoeias for absorbance accuracy and linearity in the far UV
Starna Green (250-650 nm) - Unique general-purpose reference for absorbance accuracy and linearity and wavelength accuracy in the UV and visible
Deep UV Reference (190-220 nm) – qualification in the deep UV: unique to Starna
Metal-on-Quartz Neutral Density Filters (250-635 nm) - durable filters with UV capability – now recommended by USP
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
Wavelength References
Holmium Oxide Liquid (240-650 nm) - the most widely used reference for wavelength accuracy – cited by all major Pharmacopoeias
Cerium Oxide liquid (200-300 nm) - recommended by Pharmacopoeias for wavelength accuracy in the far UV.
Didymium Oxide Liquid (290-870 nm) – cited by the Pharmacopoeias and with useful peaks in the NIR
Combined Holmium/Didymium Oxide Liquid (240 to 795 nm) – evenly spaced peaks over a wide range
Starna Green (250-650 nm) - Unique general-purpose reference for absorbance accuracy and linearity and wavelength accuracy in the UV and visible
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 from UV to NIR.
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
Deep UV Reference (190-220 nm) – qualification in the deep UV: unique to Starna
SamariumOxide Liquid (230 – 560 nm) – for the commonly used region from 200 nm to 500 nm
Stray Light (Stray Radiant Energy) References
Stray Light Cut-off Filters –Specified Wavelength Method – (175-385 nm) accepted by European and US Pharmacopoeias
Stray Light Cut-off Filters – Filter Ratio Method (175-385 nm) – recommended by US Pharmacopeia for measuring low stay light levels
Stray Light Glasses (220-440 nm) - convenient routine check for stray light
Resolution (Spectral Bandwidth) References
Toluene in Hexane (265 – 270 nm) - the most widely used resolution reference – accepted by all major Pharmacopoeias
Toluene in Methanol (265 – 270 nm) - resolution check for Derivative Spectroscopy.
Benzene vapour (230-270 nm) - resolution reference for instruments with spectral bandwidths less than 1 nm
References for Visible Spectroscopy
Instruments for use in the visible region only are less subject to regulation than those used in the UV. Good practice, however, requires that they are also qualified to ensure that they are performing correctly. Starna supplies a range of Certified Reference Materials for use in the visible region.
Ideally, references should be chosen whose calibrated values “bracket” the conditions to be used for analysis.
Visible Instrument Qualification Kit
Product Enquiry
Part number: RM-1N3N5DHG
A set of robust glass reference materials for qualifying visible-only spectrophotometers for photometric accuracy and wavelength calibration.
Neutral Density Filters (1.00, 0.50 & 0.25 A) - Absorbance Accuracy, 440-635 nm. More information
Holmium Glass Filter - Wavelength Accuracy, 240 - 640 nm. More information
Absorbance References
Neutral Density Filters (440-635nm) - glass filters with absorbances from 0.04 A to 3.5 A
Metal-on-Quartz Neutral Density Filters (250-635 nm)– equivalent to NIST SRM 2031
Starna Green (250-650 nm) - wavelength and absorbance for instruments with bandwidths >5nm
Combined Holmium/Neutral Density glass (360 - 640 nm) – check absorbance and wavelength with one filter!
Combined Didymium/Neutral Density glass (430 - 890 nm) – check absorbance and wavelength with one filter!
Wavelength References
Holmium Oxide Liquid (240-650 nm) - the most widely used reference for wavelength accuracy
Didymium Oxide Liquid (290-870 nm) – useful peaks in the NIR
Starna Green (250-650 nm) - wavelength and absorbance for instruments with bandwidths >5nm
Holmium Oxide Glass (270-640 nm) – useful for routine checks
Didymium Glass (430 - 890 nm) – useful for routine checks
Starna wide-range wavelength reference (335 - 1945 nm) - 20 peaks for wavelength calibration from UV to NIR.
Starna Holmium Oxide/Neutral Density glass (360 - 640 nm) – check absorbance and wavelength with one filter!
Starna Didymium Oxide /Neutral Density glass (430 - 890 nm) – check absorbance and wavelength with one filter!
Samarium Oxide Liquid (230 – 560 nm) – narrow peaks throughout the spectrum
FTIR
Cell Height Finder
Near-infrared (NIR) Absorbance References
The Near-infrared region is usually defined as the range of wavelengths from 750 nm to 2500nm. Starna has developed reference materials specifically designed for absorbance qualification in this region.
Metal-on-Quartz Neutral Density Filters (250 - 3200 nm)
This Reference Material can be used to qualify the Absorbance scale, in the ultra-violet, visible and near-infrared regions of the spectrum (250 nm to 3200 nm) of spectrophotometers with spectral bandwidths not exceeding 6.5 nm. Absorbance and Transmittance values are certified at 250.0, 360.0, 465.0, 546.1, 635, 1100, 1700, 2210, 2500, and 2850 nm. Before purchase, users should check that these filters are
compatible with their spectrophotometer - see data sheet.
More information
NIR Neutral Density Filters (800 nm to 3200 nm)
This Reference Material is specially designed for the wavelength qualification of near-infrared reflectance spectrophotometers over the range 900 nm to 2600 nm. These references can be used to qualify the absorbance accuracy and linearity of near-infrared spectrophotometers with a spectral bandwidth of 6.5 nm or less, over the wavelength range 800 nm - 3200 nm. Calibration values (in % Transmission and Absorbance) are certified at 1100, 1700, 2210, 2500 and 2850 nm.
More information