Determination Of Aluminium In Samples Research Articles

Aluminium and Its Complexes in Teas and Fruity Brew Samples, Speciation and Ions Determination by Ion Chromatography and High-Performance Liquid Chromatography–Fluorescence Analytical Methods

The paper presents results of aluminium determination in samples of black and fruit teas. Total aluminium concentration was determined along with the concentration of aluminium in a cup of tea in tea samples in two price groups (>1€ and <1€). Based on the conducted study, no differences were found in aluminium concentration in black and fruit teas depending on the price group. Developed ion chromatography method was applied to determine inorganic and organic ions in tea samples, especially those which may form complexes with aluminium: fluoride, sulphate, oxalate and citrate ions. Analysis by this method using ion chromatography allowed for the determination of 12 anions: F−, HCOO−, CH3COO−, NO2−, Br−, NO3−; Cl−, CH2(COO)22−, SO42−, C2O42−, PO43− and C3H5O(COO)33− in the time of 40 min. Speciation analysis of aluminium was performed in optimised HPLC-fluorescence analytical system (with Lumogallion as a post-column reagent). It was observed that organic aluminium complexes are quickly degraded to form Al3+ which is the reason why speciation analysis in tea samples does not provide the full image of speciation distribution. Nevertheless, this developed method was successfully used in the determination of aluminium complexes with fluorides in tea samples.

The sensitive and selective determination of aluminium by spectrofluorimetric detection after complexation with N-o-vanillidine-2-amino-p-cresol

A simple, easy to use and selective spectrofluorimetric method for the determination of trace levels of aluminium has been developed. A new Schiff base, N-o-vanillidine-2-amino-p-cresol (OVAC), has been synthesized and its fluorescence activity with aluminium investigated. Based on this chelation reaction, a spectrofluorimetric method has been developed for the determination of aluminium in samples buffered at pH 4.0 using acetic acid-sodium acetate. The chelation reaction between Al(iii) and N-o-vanillidine-2-amino-p-cresol was very fast, requiring only 20 min at room temperature to complex completely. The excitation and emission wavelengths were 423.0 and 553.0 nm, respectively, at which the OVAC-Al complex gave the maximum fluorescence intensity at pH 4.0 in a 50% ethanol-50% water medium. The interference from fluoride ions was minimized by the addition of Be(2+). Other ions were found not to interfere at the concentrations likely to be found in natural waters. Under these conditions, the calibration plot was linear up to 1000 microg L(-1) (r = 0.999). The limit of detection (3sigma) for the determination of Al(iii) was 0.19 microg L(-1) and the precision for multiple determinations of 3 ng mL(-1) Al(iii) prepared in ultra-pure water was found to be 0.29% (n = 16). The Schiff base ligand could be used to determine ultra-trace aluminium from natural waters. Analysis of environmental certified reference materials showed good agreement with the certified values. The procedure was found to be equally applicable to both fresh water and saline solutions (including sea water) using either normal external calibration or the standard additions method.

Chemical partitioning of aluminium in rocks, soils, and sediments acidified by mining activity.

The work presented describes the application of different analytical approaches for study of aluminium mobility in rock, soil, and sediment samples affected by mining activity (secondary quartzites with sulfidic deposits). For this purpose we used a combination of the single extractions, the optimized BCR three-step sequential extraction procedure (SEP), and reactive aluminium determination after chelating ion-exchange on Ostsorb (Iontosorb) Salicyl by a batch technique with flame atomic absorption spectrometry quantification. The single extraction agents H(2)O, KCl, NH(4)Cl, and BaCl(2) were found to be the best for the quantitative estimation of the aluminium mobility in rocks, soils, and sediments caused by acidification of the environment. This fact was confirmed by reactive aluminium determination in the same samples. The vast majority of the aluminium content of samples after application of the optimized BCR three-step SEP is in the residues. The available fraction of aluminium extracted by dilute CH(3)COOH in the first step of this procedure correlates with the reactive aluminium content. The amounts of aluminium released in the second and the third steps and the sums from steps 1-3 of this procedure are closely associated with the aluminium content values obtained by the single dilute HCl leach. The accuracy of results obtained was verified with only informative values for individual fractions of the BCR three-step SEP because of the absence of suitable certified or standard reference materials. The amounts of the reactive aluminium determined in samples was in the range 12-82% of total soluble Al in the filtered H(2)O extracts. It was confirmed that the acidified polluted samples contain the most of reactive Al content, which is responsible for its toxicity.

Determination of aluminium in samples from bone and liver of elderly norwegians

Recent reports associating aluminium with several skeletal and neurological disorders in humans suggest that exposure to aluminium may pose a health hazard. In connection with an epidemiological study on aluminium and Alzheimer's disease, information on the body burden of aluminium was needed. Aluminium is stored in the body mainly in bone and soft tissues such as the liver. Therefore, an analytical procedure was developed for the determination of aluminium in the head of femur and the liver using graphite furnace atomic absorption spectrometry. Problems in such analyses are associated with low levels of aluminium, risk of contamination during sample preparation, inhomogeneity of the sample tissues, and complexity of the matrices. Bone samples gave poorer repeatability compared to liver samples and up to four replicate analyses were performed. In the analyses of the digested bone samples, severe chemical interference occurred when these either contained much dissolved bone mineral or had a high A1 concentration. It is possible that this interference is brought about by formation of aluminium phosphate in the graphite tube. The analytical results for bones are given relative to ash weight because the samples sometimes contained a lot of fat. The ash weight of the bone tissue varied between 8 and 69 per cent. The material consisted of 84 samples of head of femur and 95 liver samples from deceased elderly Norwegians. Two cases had high A1 levels in bone (16.8 and 18.0 mg/kg ash weight) and liver (10 and 22.7 mg/kg dry weight) tissues. The remaining cases showed about ten to fifteen-fold variation of the A1 level in both liver (0.4 - 5.7 mg/kg) and bone (0.5 - 5.8 mg/kg). There was no correlation between the level in liver and bone when the two cases with the highest levels were excluded.

Determination of aluminium in human tissues and body fluids by Zeeman-corrected atomic absorption spectrometry.

A procedure is described for the determination of aluminium in samples of human origin. It is based on Zeeman-corrected atomic absorption spectrometry, and the method of standard additions is used for the quantitation. Plasma and urine samples were analysed directly after dilution and tissue samples after wet digestion with nitric acid. For plasma samples, the precision was approximately 5%(relative standard deviation) at the 50 µg l–1 level, and the accuracy of the method was evaluated by analysing the NBS reference material bovine serum. For tissue samples, the accuracy and precision were determined from recovery experiments. Examples of aluminium concentrations found in human plasma, urine, bone, liver and brain are given.

Spectrofluorimetric and spectrophotometric determination of aluminium with the salicyloylhydrazones of pyridine-2-aldehyde and pyridoxal

The analytical applications of the salicyloylhydrazones of pyridine-2-aldehyde (SHPA) and pyridoxal (PSH) are described. PSH reacts with aluminium at pH 2.0 to produce a yellow complex (λmax.= 420 nm, Iµ= 2.5 × 104 l mol–1 cm–1); another complex can be detected at pH 4.75 (λmax.= 425 nm, Iµ= 3.1 × 104 l mol–1 cm–1). SHPA reacts with aluminium at pH 5.4 to give a complex having a blue fluorescence (λex.= 382 nm, λem.= 440 nm) and both reagents are compared. Sensitive and selective methods are proposed for the determination of aluminium ions. The yellow aluminium - PSH complex formed in acid medium (pH = 2.0) has been used for the determination of aluminium in samples of steel and a Portland cement.