Holmium perchlorate

The wavelength scale of a UV/visible spectrophotometer is checked by determining the specified wavelength maxima of a 5% w/v solution of holmium perchlorate. Figure 4.6 shows the spectrum of holmium perchlorate, the tolerances for ealibration wavelengths specified by the BP are 241.15 1 nm, 287.15 1 nm and 361.5 1 nm. 

The absorbance maxima of a 5% w/v solution of holmium perchlorate between 200 and 400 nm. 

Figure 11. Holmium perchlorate solution, 10 mm path length and 1 nm SBW. For the latest values J C Travis et al, J. Phys. Chem. Ref. Data, 34(1) (2005) 41-56.

A complex of holmium perchlorate coordinated with 1-glutamic acid was prepared with a purity of 98.96%. The compound was characterized by chemical, elemental and thermal analysis. Molar heat capacities of the compound were determined by a high-precision automated adiabatic calorimeter from 78 to 370 K. The dehydration temperature, dehydration enthalpy, entropy and the standard enthalpy of formation were reported [183],... 

Wavelength reproducibility can be simply checked by an overlay of repetitively recorded line emitter or holmium perchlorate solution spectra. Since wavelength reproducibility is especially important in kinetic investigations, a chemical reaction can also be used as standard, for which the... 

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

A number of reference chemicals with well-defined UV spectra have been used for detector wavelength calibration, e.g., uracil, erbium perchlorate, holmium oxide, caffeine, etc. 

For most routine purposes, a solution of holmium oxide in perchloric acid will provide a convenient method for routinely checking the calibration of the wavelength scale. Figure 11 shows a typical spectrum. The values are known to within 0.2 nm and are adequate for most solution work. If wavelengths in the region below 241 nm are needed, then either atomic line sources such as a vapour discharge lamp or other rare earth solutions may be used. 

The lutetium hahdes (except the fluoride), together with the nitrates, perchlorates, and acetates, are soluble in water. The hydroxide oxide, carbonate, oxalate, and phosphate compotmds are insoluble. Lutetium compounds are all colorless in the solid state and in solution. Due to its closed electronic configuration (4f " ), lutetium has no absorption bands and does not emit radiation. For these reasons it does not have any magnetic or optical importance, see also Cerium Dysprosium Erbium Europium Gadolinium Holmium Lanthanum Neodymium Praseodymium Promethium Samarium Terbium Ytterbium. 

Figure 3 Absorption spectrum produced by holmium oxide in perchloric acid solution, provided as a sealed cell certified reference material. Measured at the sample position, in a high performance reference commercial spectrophotometer, with air as the reference.

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