What substances are used as a Matrix?
• alpha-cyano-4-hydroxycinnamic acid (a-CN) • MW 189.04 Da • a-CN is preferred for many applications because it yields cleaner backgrounds • often used for peptide analysis • a good matrix choice for samples with MW <10,000Da • sinapinic acid (3,5-dimethoxy-4-hydroxycinnamic acid) • MW 224.07Da a good choice for samples with MW >10,000Da • is a “hotter” matrix recommended for samples in the mass range > 3.5kD • is a common for protein analysis • nicotinic acid • 2-(4-hydroxyphenyl-azo)-benzoic acid • HABA • concentration of 10 mg/mL • Observations: Most widely applicable matrix HABA is useful for the analysis of organic compounds since it is highly soluble in most organic solvents. It is generally understood that good spectra are acquired when the matrix and the analyte are miscible in the same solvent. HABA meets this criterion. • 2,5-dihydroxybenzoic acid • symbol: DHBA • concentration of 10 mg/mL • ferrulic acid • concentration of 10 mg/mL The ions produced are usually protonated mo
