170135_inorganicventures_flipping

3:13 Sampling and sub-sampling

Contamina(on Issues During Sampling (cont.)

Water: A typical EPA scenario consists of:

Water samples are taken in polyethylene bo8les that are pre-washed with detergent, followed by 10% HNO3 and disElled water. ↓ The pH of the sample is adjusted to < 2 with HNO3 to minimize adsorpEon. ↓ Water samples should be stored at 4̍C to minimize changes due to biological acEvity (e.g. - redox processes).

The analyst should be concerned about contaminaEon from the collecEon container as well as adsorpEon and precipitaEon of the analyte(s) of interest aUer collecEon. Of the elements of environmental interest, Hg is the most difficult to keep in soluEon.

3:14 Sampling and sub-sampling

Contamina)on Issues During Sampling (cont.) Environmental Contamina.on of Samples by Various Elements (Ref 1)

Concentra)on (μg/g)