There are several ELISA kits commercially available for the detection of OxPC including OxPAPC (https://avantilipids.com/product/330600).
You should be aware that ELISA kit is a screening test, however OxPAPC is generally composed by a mixture of long- and short-chain OxPC compounds (Article Structural motifs in primary oxidation products of palmitoyl...
). ELISA kits will not give you information on the molecular species present. For this you'll need to do LC-MS analysis to identify and quantify the OxPAPC present in your sample (
Article Distribution of plasma oxidised phosphocholines in chronic k...