The sodium Iodide liquid filter (UV10) consists of 10 g/l sodium Iodide in pure water. This filter is suited to check the stray light of a spectrometer in the spectral range between 210 nm and 259 nm, its cut off is at about 259 nm.
Two regulations - two measuring methods
Currently there are different methods used in the European Pharmacopoeia (EP) and in the United States Pharmacopeia (USP) to determine the stray light.
Measurement of sodium iodide (UV10) against reference filter pure water (UV12)
Typical spectrum of the stray light filters in accordance to Ph. Eur.
Measurement of sodium iodide (UV10, PL 10mm) against reference filter sodium iodide (UV10H, PL 5mm)
Typical spectrum of stray light filters according to USP <857>
Experiences from daily practice show that the values determined in this stray light measuring method are instrument-dependent. This means the wavelength of the peak varies depending on the spectrophotometer performance. It is important for the user to know that the measured maximum absorption in the checked range is decisive for this checking method and that it should be higher than 0.7 Abs.
|ARTICLE-NO.||EP-Set: 667101 (UV10/UV12) Request this article |
USP-Set: 667101H (UV10/UV10H)
|APPLICATION||Checking stray light in the spectral range of 210 - 259 nm according to EP and USP|
|CONTENT||Sodium Iodide 10 g/l in pure water|
|STANDARD CERTIFICATION||Cut-off wavelength: 259 nm |
Slit width: 2 nm; with DAkkS calibration certificate
|POSSIBLE CERTIFICATION||Cut-off wavelength: fix |
Slit width: 2 to 5 nm