PH 39 (COSMETICS): 1 This test applies only where peptide linkages, are
present

2 used to detect and quantify proteins in their hydrolysates

3 most interesting sulfur amino acid, CYSTINE, may be reduced to general thiol groups (—SH) by a number of reducing agents:

4 most important reducing agent; forms the basis of most PERMANENT WAVING PROCESSES & hair straightening products

Question

1 This test applies only where peptide linkages, are 
present

2 used to detect and quantify proteins in their hydrolysates

3 most interesting sulfur amino acid, CYSTINE, may be reduced to general thiol groups (—SH) by a number of reducing agents:

4 most important reducing agent; forms the basis of most PERMANENT WAVING PROCESSES & hair straightening products

LEIGHTON DWIGHT OBILLOS · Accepted Answer

1 Alkali Hydrolysis

2 Ruhemann’s Purple

3) 
1 mercaptans such as Thioglycollic acid, Alkali bisulfite 
2 Phosphorus  derivatives like Tertrakis (methylol),
Phosphonium chloride (TMPC)

4 Ammonium thioglycolate

1 Alkali Hydrolysis 2 Ruhemann’s Purple 3) 1 mercaptans such as Thioglycollic acid, Alkali bisulfite 2 Phosphorus derivatives like Tertrakis (methylol), Phosphonium chloride (TMPC) 4 Ammonium thioglycolate