The compounds can be produced by reacting a monoalkyl maleate with a cysteic acid salt or by reacting a bromosuccinate with a cysteic acid salt.

The cysteic acid groups remain, providing hydrophilic sites within the hydrogel.

A higher degree of partial oxidation results in a greater abundance of hydrophilic cysteic acid groups in the hydrogel.

After allowing to stand for a while, the moisture content and the cysteic acid content of the sample hair are measured.

This solution is not used if the stock standard solution (3.27.1) contains cysteic acid and methionine sulphone.