impurity

On its website, Elemetal says its specialized facilities melt gold sources such as scrap jewelry and impaired bullion to separate impurities and obtain refined gold.

Electrospinning using a starch-rich ingredient such as white flour is more challenging than using pure starch, as the impurities -- the protein and cellulose -- make the mixture more viscous and unable to form fibres.

No longer able to clean the blood of impurities, the Frankensteined kidney becomes a "pathological neuro-immune endocrine organ," as the UVA researchers describe it in a new scientific paper, that can cause serious health problems.

A Forest Service report said it could not rule out potential heavy metal impurities in retardant, which was hosed down from firefighting planes.

The drug, which fights cravings, was available a few years ago on the NHS under the brand name Champix but was withdrawn due to some impurities.