Holmium oxide

On some detectors, a holmium oxide filter or special holmium oxide cell is integrated into the detector these can then be moved into the optical path during calibration mode. The detector itself or associated control software may then be able to check for wavelength accuracy. Note If the filter or cell is made of glass, and not quartz, 241 nm may not be used. 

Hohnium chloride also can be prepared by heating holmium oxide with ammonium chloride ... 

Hohnium oxide occurs in nature, usually associated with small quantities of other rare-earth oxides. Commercial applications of this compound have not been explored fuUy. It is used in refractories and as a catalyst. Characteristic spectral emission lines of holmium oxide glass are used to cahbrate spectrophotometers. ... 

Holmium oxide is prepared by thermal decomposition of carbonate, oxalate, hydroxide, nitrate, sulfate, or any oxo salt of holmium ... 

Holmium oxide solution is commercially available in a sealed 1-cm cuvette. It is a very convenient and versatile wavelength standard. The standard is suitable for UV-Vis spectrophotometers typically used in pharmaceutical laboratories, with spectral bandwidth ranging from 2 to 0.5 nm. The certified wavelength values of the peaks are listed in Table 10.3. When a spectral bandwidth of... 

Figure 10.3. (c) Absorption spectrum of holmium oxide filter. 

Holmium oxide and Easy to use Glass filter absorbs strongly... 

Table 10.3. Wavelength Assignment 4% Holmium Oxide in 10% Perchloric Acid...

Holmium Oxide Solution Wavelength Standard from 240-640 nm, SRM 2034, NIST Spec. Publ. 260-102, 1986. 

There are many ways to check the wavelength accuracy of a UV-Vis detector. For detectors with built-in wavelength verification, the deuterium line at 656 nm or the absorption bands at 360, 418, 453, and 536 nm in a holmium oxide filter... 

Spectral Studies. UV spectra were recorded in methanolic solution (40-60 ppm) on a Beckman Model 26 spectrophotometer matched quartz cells having a 1-cm path length were used. A holmium oxide spectrum was recorded prior to the analysis of the samples for QA purposes. 

J. C. Travis et al., Intrinsic Wavelength Standard Absorption Bands in Holmium Oxide Solution for UV/Visible Molecular Absorption Spectrophotometry, J. Phys. Chem. Ref. Data 2005,34, 41. 

Figure 10.3. (d) Absorption specti um of holmium oxide solution. 

Holmium metal tends to be stable at room temperature. In moist air and at higher temperatures, it becomes more reactive. For example, it combines with oxygen to form holmium oxide (H02O3), a yellow solid. Like most other metals, the element also dissolves in acids. 

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