EN 12498:2005

Foreword
1 Scope
2 Normative references
3 Principle
4 Reagents
   4.1 General
   4.2 Nitric acid (HNO[3]), 65% (d = 1.42)
       4.2.1 Nitric acid (4.2), diluted 1:1 (V/V) with water
       4.2.2 Nitric acid (4.2), diluted to 1% (V/V) with water
   4.3 Hydrochloric acid (HCl), 36% (d = 1.19)
   4.4 Hydrochloric acid (HCl), 0.3 mol/l solution
   4.5 Cadmium - stock solution (Cd) = 1000 mg/l
   4.6 Lead - stock solution (Pb) = 1000 mg/l
   4.7 Matrix modifiers
       4.7.1 Ammonium dihydrogen phosphate (NH[4]H[2]PO[4])
             solution, 100.0 g/l
       4.7.2 Palladium nitrate (Pd(NO[3])[2]) solution,
             21.7 g/l (= 1% Pd)
       4.7.3 Magnesium nitrate (Mg(NO[3])[2]) solution,
             61.0 g/l (= 1% Mg)
   4.8 Gases for atomic absorption spectrometry
5 Apparatus
   5.1 General
   5.2 General laboratory equipment
   5.3 Volumetric flasks, 1000 ml
   5.4 Analytical balance, accuracy 0,1 mg
   5.5 Micropipettes from 5,0 [mu]l to 20,0 [mu]l with
       plastique tips (high density polyethylene/polypropylene
       bottles)
   5.6 Atomic absorption spectrometer, with graphite tube
       furnace, and with background correction or inductively
       coupled plasma atomic emission spectrometer with background
       correction and radio frequency-generator
6 Preparation of sample
7 Procedure
   7.1 General
   7.2 Preparation of reference solutions
   7.3 Determination of cadmium and lead
       7.3.1 General
       7.3.2 Calibration curve
       7.3.3 Suggested spectrometer settings
       7.3.4 Determination of blank value
8 Expression of results
9 Precision
10 Test report

This European Standard is one in a series of Standards for the determination of heavy metals in an aqueous extract of paper or board intended for contact with food. This European Standard specifies the test method for the determination of cadmium and lead in an aqueous extract.It is applicable to paper and paperboard with extractable metal contents exceeding -0,1 mg per kg for cadmium;-0,6 mg per kg for lead.NOTE 1The above limits of determination are achieved by multiplying the actual limits existing today or proposed in Europe by 0,2.NOTE 2Metal content levels below those given can be measured by this European Standard if very sensitive equipment is available and if all other laboratory conditions fulfil the requirements for trace element analysis.