Rare earth elements can be determined on a CGC column 3 x 150 mm packed with Separon SGX C 18 modified with sorbed ammonium dodecyl sulfate (from solutions with c = 5 mmol l -1 ) by isocratic or stepwise gradient elution with ammonium DL-α-hydroxyisobutyrate solution (20-160 mmol l -1 ) at pH 4·5. (cas.cz)
The method of post-column derivatization with a solution of Arsenazo III (5 μmol l -1 ) in 0·1M formate buffer at pH 2·9-3·0 for photometric detection enables 10-150 or 6-155 ng of rare earth ions in sample ( n = 5-7). (cas.cz)
The procedures were applied to the determination of rare earth elements in samples of apatite, oxide concentrates and a luminophor, and a very good agreement with the results obtained by optical methods was achieved. (cas.cz)
Calcium4
It is present in the Arsenazo III (A3) method (Biolabo®) and used daily for the determination of calcium in parenteral nutrition preparations. (gerpac.eu)
Measurement of the ionized calcium component is generally obtained in specialized laboratories and through a special procedure. (medscape.com)
Determination1
Determination of lanthanide (III) ions were performed with ion chromatography techniques. (scialert.net)
Stability2
i) No chemical risk for the manipulator, ii) Constant cost and time handling (30 minutes for 10 samples), iii) Method validated according to the recommendations of the International Harmonization Conference (linearity over 5 points range repeated 3 days , reproducibility, accuracy, fidelity on 1 point of range repeated 6 times 3 consecutive days, no matrix effect), iiii) Time stability of the colorimetric reaction. (gerpac.eu)
Many of the applications of crown ether compounds are based on their complexing ability with various cations and hence, study of the stability of their complexes with metal cations and also the factors which affect their stability are important in many procedures such as separation, extraction, ion transport, chromatography and selectivity of analytical methods. (scialert.net)