Sensitive spectrophotometric determination of La(III) with 1-(2-pyridylazo)-2-naphthol

2222's picture
Journal Title, Volume, Page: 
Microchemical Journal, Volume 30, Issue 2, October 1984, Pages 231-234
Year of Publication: 
Kamel Abdel Hadi
Current Affiliation: 
Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine
Preferred Abstract (Original): 

A simple and sensitive method for spectrophotometric determination of lanthanum has been developed. At pH 9.6, in presence of 50% ethanol, lanthanum reacts with 1-(-2-pyridylazo)-2-naphthol (PAN) to form a red complex which has two absorption maxima, at 545 and 510 nm. The molar absorptivity at 545 nm is 0.55 × 104 liters · mol−1 cm−1. On the other hand, lanthanum reacts with PAN in pure ethanol to form a red complex at 530 nm, with high molar absorptivity (8 × 104 liters · mol−1 cm−1).