Table 4. Heavy-atom reactivity of the histidine-containing peptide.

	Sodium acetate		Sodium citrate			MES	Sodium cacodylate		HEPES		TrisHCl
pH	4.0	5.0	4.0	5.0	6.0	6.0	5.5	6.5	7.0	8.0	7.5	8.5
Platinum potassium thiocyanate			+	+	+	+++			+	+
Platinum potassium iodide			+	+	+	+++			+	+
Potassium hexabromoplatinate(IV)			+	+	+	+++			+	+
Potassium tetrachloroplatinate(II)			+	+	+	+++			+	+
Potassium tetrabromoplatinate(II)	+	+	+	+	+	+	+	+	+++	++		+
Diamino platinum dinitrate	+	+	+	+	+	+++	+		+	+
Potassium tetranitroplatinate(II)			+	+	++	+++			+	+
Dichloro(ethylenediamine)platinate(II)	+	+	+	++	+	+++	+	+	+	+		+
Potassium tetracyanoplatinate(II)			+	+	+	+++		+	+	+
Ammonium tetrachloroplatinate(II)			+	+	+	+++			+	+
Potassium hexachloroplatinate(IV)			+	+	+	+++			+	+
Potassium tetrachloroaurate(III)	++	++		+		+++	+++	++			++	++
Sodium tetrachloroaurate(III)	++	++		+	+	+++	++	++			+	+
Gold(III) chloride	+++	+++	+	+	+	+++	+++	+++			+++	+++
Gold chloride	+	+++	+	+	+	+++	+++	+++			+++	++
Gold sodium bromide	+		+	+	+	+	+	+		+
Potassium tetrabromoaurate(III)	+	+	+	+	+	+++	+	+
Gold sodium thiosulfate			+	+	+	++	+	+			+	+
Gold(I) potassium cyanide	++	++	+	+	++	++	++	++			++	+++
Gold potassium thiocyanide		+	+	+	+	++	+	+			++	++
Thiomersal	+	+	+	+	+	++	+	+	++	+++	+
Mersalyl	+	+	+	+	+	++	+		++	+++	+	+
Mercury(II) acetate	++	++	+	+	++	+++		+	+	+		+
PCMBS	+	+	+	+	+	++	+	+	++	+++		+
Potassium mercury tetraiodide			+	+	+	+++			+	+++	+	+
Methylmercury(II) chloride			+	+	+	+++			+	+	+
Methyl mercury(II) acetate	+++	+	+	++	++	+++			++	+++	+	+
Ethylmercury(II) phosphate	+++	+++	++	++	++	+++			+++	+++	+	+
Mercury(II) cyanide			+	+	+	+++			+	+
Mercury(II) bromide			+	+	+	+++			+	+
Mercury(II) chloride			+	+	+	+++			+	+	+	+
Methylmercury(II) bromide			+	+	+	+++			+	+
p-Chloromercuribenzoic acid			+	+	+	+++			+	+	+	+
Ethylmercury(II) chloride			+	+	+	+++			+	+	+	+
Mercury(II) iodide						+
Mercury oxide			+	+	+	+
Potassium hexachloroiridate(III)		+	+	+	+	+	+		++	+	+
Potassium hexachloroosmiate(IV)		+	+	+	+	++		+	++	+