5.2.1 Transfer a 225 g analytical unit to a 2 L beaker.

5.2.2 Add 900 mL warm water (50°C) and 20 mL of an emulsifier (Igepal CO 730).

5.2.3 Wash a magnetic stirring bar (5cm) with 1 N HCl and then with water to remove any magnetic metal particles and place in the beaker.

5.2.4 Stir 5 min on a magnetic stirrer.

5.2.5 Add 20 mL of conc. HCl and stir 1 min. The pH should be in the range of 1.5 to 7. If not, adjust with conc. HCl or conc. NH₄OH.

5.2.6 Add 0.5 g of 1:10,000 pepsin and stir 1 min.

5.2.7 Place the meat slurry in a 50°C incubator and allow to digest overnight (18 hrs).

5.2.8 Add 5 mL of Triton X-114 and stir for 10 min.

5.2.9 Remove the magnetic stirring bar with a larger one and grip the first magnetic stirring bar in the centre.

5.2.10 With a strong stream from a wash bottle, wash the metal particles off the stirring bar removed from the slurry, into a 400 mL beaker, first with 1% sodium lauryl sulfate, then with 95% alcohol, and lastly with water. Make sure both ends are washed until no more particles are on the ends of the magnet.

5.2.11 Replace the magnet into the slurry and repeat the 10 min stir and wash 2 more times, collecting the washings in separate beakers.

5.2.12 Filter each washing through separate labelled ruled filter paper using suction filtration apparatus.

5.2.13 Transfer filter papers to petri dishes and moisten with glycerol-ethanol mixture.

5.3.1 Examine each filter paper with a stereoscopic microscope at 30x magnification for magnetic metal particles.

5.3.2 Count magnetic metal particles in the size ranges: 0.1-<2.0 mm and ≥2.0 mm.

5.3.3 For particles <0.1 mm, estimate their numbers on each plate by counting several fields, taking the average and multiplying by the total number of microscopic fields on the filter paper.

5.3.4 To ensure that a questionable particle does not consist of a cluster of particles, touch it with a fine non-magnetic probe. (Particles may: (a) be entire, (b) separate into several smaller ones, and/or (c) break into a fine dust (i.e. particles <0.1 mm).

5.4.1 After the MMP isolation is completed, stir the slurry by hand for 1 min with a rubber policeman and allow to stand undisturbed for 1 h. Decant the slurry into a No. 230 sieve leaving the heavy residue in the beaker. With fingers feel the slurry on the sieve for bone fragments. Record the number and size of bone fragments found. After checking for bone fragments on the No. 230 sieve discard contents of the sieve.

5.4.2 Fill the beaker with warm water to about the 1 L mark and allow to stand for 10 min.

5.4.3 Decant and discard slurry without disturbing the heavy filth at the bottom. If any meat material remains, refill and let it stand 10 min again and then decant. Do this until no meat material remains at the bottom.

5.4.4 Filter the heavy filth at the bottom of the beaker onto a preweighed oven-dried filter paper. If any fat remains on the paper, wash with hot detergent (1% sodium lauryl sulfate) and then rinse well with water.