ALUMINUUM DETERMINATION IN PARENTERAL SOLUTIONS AFTER ON-LINE PRECONCENTRATION IN IMMOBILISED L-METHIONINE BY ICP OES

P.H. PACHECO, R.A. GIL, G. POLLA, P. SMICHOWSKI, L.D. MARTINEZ

MICROCHEMICAL JOURNAL

Elsevier

Año: 2008 vol. 89 p. 1 - 6

0026-265X

Aluminium is an element found in biological samples at low concentrations and aluminum-related neuropathological diseases in human beingshave been reported. For this reason the determination of Al in this type of samples requires the development of enrichment methods capable ofimproving the instrumental detection for this analyte.L-methionine immobilized on controlled pore glass (CPG) was tested for the retention of aluminium. This adsorbent material was packed in aconical minicolumn and connected to an on-line flow injection system. An inductively coupled plasma optical emission spectrometer associated toan ultrasonic nebulization system (USN-ICP OES) was used for aluminium detection. Al(III) was retained at pH 12.5 and removed from thecolumn with 20% (v/v) HNO3.The precision of the preconcentration method was evaluated by passing a measured volume of aluminium standard solution (1 μg L−1) throughthe minicolumn and repeating this procedure five times. The relative standard deviation (RSD) was 2.5%, calculated with the peak heightsobtained. A total enhancement factor of 1600 was attained for a sample volume of 10 mL (10-fold for the ultrasonic nebulization system and 160-fold for the preconcentration methodology). The detection limit (DL), calculated as the amount of Al required to yield a net peak equal to threetimes the standard deviation of the blank solution, was 25 ng L−1.The proposed system was successfully applied to the determination of aluminium in urine, hair, and saliva samples, which were pretreatedusing a microwave digestion methodology with the introduction of a digestion program for saliva. The average aluminium levels found in urine,hair, and saliva samples were 5.5 μg L−1, 19 μg g−1 and 93 μg L−1 respectively.© 2007 Elsevier B.V. All rights reserved.