Aluminium analysis by inductively-coupled plasma emission spectrometry
Aluminium is not thought to be an essential trace element but it is clinically relevant because it can accumulate in patients with renal disease. Tap water containing aluminium in amounts from 50 to over 1000 µg/L can cause a toxic syndrome in uraemic patients when this water is used during dialysis. The syndrome can present variably as encephalopathy (dialysis dementia), hypercalcaemic osteomalacia, and microcytic anaemia. Excessive prescription of aluminium -based phosphate binders can also cause bone disease in some renal patients who may be hyperabsorbers of oral aluminium. Contaminated intravenous fluids such as protein hydrolysates and various plasma protein fractions are another potential cause of aluminium toxicity.
Renal association guidelines recommend measurement of aluminium every 3 months in haemodialysis patients, and peritoneal dialysis patients taking aluminium hydroxide. Water used for haemodialysis is usually purified by reverse osmosis. Regular checks are necessary to ensure that aluminium concentrations in purified water are less than 10 µg/L.
The accumulation of aluminium in brain tissue has been linked to the pathogenesis of Alzheimer’s disease, however, the evidence for this remains controversial.
Sample Requirements and Reference Ranges
|Sample Type||Plasma, urine, water, dialysis fluid|
|Container||Plasma: Heparin, or ‘Trace Metal’ (plain or heparin).
Water and other fluids: Universal container
|Precautions||Prone to contamination. The lithium blood tube should be all-plastic, free of rubber rings or other sealing materials in the cap. Those produced by Greiner, Sarstedt and Vacutainer are suitable.
Powder inside plastic gloves can be a source of aluminium contamination when handling samples.
Universal containers should be all plastic and free of sealing materials in the cap. 30mL polypropylene Sarstedt (code 63.9922.252) are suitable.
|Minimum volume*||Plasma: 450 µmol/L (minimum)
Water and other fluids: 3mL.
|- plasma||< 0.5 µmol/L
> 3.7 (concern level in adults)
> 2.2 (concern level in children)
|- urine||< 1.0 µmol/L|
|- tap water||< 100 µg/L (EU limit for drinking water)|
|- dialysis fluid||< 10 µg/L|
|Turnaround time||1 week|
|Method||Inductively coupled plasma/emission spectrometry|
* This is the absolute minimum volume; this is insufficient to carry out a repeat analysis in the event of an analytical problem.