for the following products
1-Maleinimido-3-oxo-7,10,13,16,19,22,25,28-octaoxa-4-azahentriacontan-31-oic acid | 31-(2,5-Dihydro-2,5-dioxo-1H-pyrrol-1-yl)-29-oxo-4,7,10,13,16,19,22,25-octaoxa-28-azahentriacontanoic acid | mal-dPEG(8)-COOH | Mal-peg8-cooh and Mal-amido-PEG8-acid
