EPAL's laboratories have the credentials for characterising metal in sludge, sediment, and leachate. The testing method was developed internally (internal method) by resorting to the inductively coupled plasma mass spectrometry technique. This technique enables the determination of the following metals: lithium, beryllium, aluminium, vanadium, chromium, manganese, cobalt, nickel, copper, zinc, arsenic, selenium, molybdenum, cadmium, antimony, barium, mercury, thallium, lead, and uranium.

This methodology is based on the EPA 3051 method 'Microwave Assisted Acid Digestion of Sediments, Sludge, soils and Oils', which consists in extracting acid through microwaves - equivalent to the conventional extraction method using nitric acid, or nitric acid and chlorhydric acid as an alternative.

Leachates are determined based on the principles of standards DIN 38414 'Sludges and Sediments (group S) – Determination of leachability by water (S4)' and EN 12457-2, where later on metals in eluate shall be analysed by means of inductively coupled plasma mass spectrometry. The following table shows technical specifications for the metal testing method.

Quantification limits and expanded uncertainty for the metal methodology

Parameter	Quantification Limit	% Expanded Uncertainty
Li	10,0 mg/kg	10
Be Mo Cd Tl Pb U	5,00 mg/kg	15
Al	500 mg/kg	20
V Cr Ni	10,0 mg/kg	20
Mn Ba	100 mg/kg	15
Co As Sb	5,0 mg/kg	20
Cu	100 mg/kg	20
Zn	500 mg/kg	15
Se	20,0 mg/kg	20