Clean up data base

We have a database that needs to be cleaned up and standardized. Here are the details: 1. We have a master list of around 23,000 companies. We need to remove duplicate names from these. Please note we have already used duplicate function in excel and other common methods such as looking for common errors. We need a manual check for each entry. 2. We have another data set of around 8,500 companies. However these list of companies dont match with the master list. These need to be matched with the master list. In case they dont match suggestions need to be made to update the master list. Please note we have already used vlookup to match these records with the master list of companies. We would need someone to do a vlookup and then look at each of the missing entries individually. Attention to detail is a must as every entry is important!