6 research outputs found
Spectrophotometric determination of erbium using kojic acid dye in different rare earth concentrates
A sensitive and selective spectrophotometric method was studied for the determination of erbium (Er) with kojic acid dye (koj) and cetylpyridinium chloride (CPC) as a cationic surfactant from Egyptian monazite and xenotime concentrates using third derivative spectrophotometry. The calibration curve was linear from 1 to 150 µg/mL erbium. The influence of various parameters and reaction conditions for optimum complex formation were investigated. The relative standard deviation for determination of 1 µg/mL erbium was found to be 1.5 after 5 repeated determinations with percentage error for Er determination from monazite and xenotime concentrates 6.4% and 4.48% respectively. The molar absorptivity of conventional and third derivative spectrum were 0.14 × 103 M−1 cm−1 and 0.13 × 103 M−1 cm−1 respectively and the detection limit was 1 µg/mL. Keywords: Erbium, Kojic acid dye, Cetylpyridinium chloride, Egyptian monazite, Xenotim
Alterations in proteins and amino acids of the Nile cyanobacteria Pseudanabaena limnetica and Anabaena wisconsinense in response to industrial wastewater pollution
The effect of industrial wastewater on the Nile cyanobacteria Pseudanabaena limnetica and Anabaena wisconsinense was investigated. The data showed that P. limnetica was more sensitive to pollution than A. wisconsinense. The treatments with different levels of wastewater exerted pronounced reductions in protein and amino acids content. SDS-PAGE analysis revealed that the cyanobacteria grown in the industrial wastewater showed induction in the synthesis of certain polypeptides and repression of others. The treatments of P. limnetica with wastewater stimulated the appearance of six protein bands with molecular masses of 28, 30, 31, 32, 58 and 97 kDa. The same treatments caused the disappearance of 20, 38 and 56 kDa. The structural protein pattern of the treated A. wisconsinense showed appearance of 16, 30, 170 and 230 kDa and disappearance of 56 kDa. The treatment of the two investigated cyanobacteria with different levels of wastewater stimulated the biosyntheses of different amino acids and inhibited others