If you are interested, here are some hard and reliable data on US chemist income from annual salary survey by American Chemical Society.
Basically, higher degree, more experience, and working in industry translate into higher salary, no surprise here. A brief summary for 2007:
BS MS PhD
industry 70K 88K 110K
government 67K 76K 105K
academic 47K 53K 70K
for more details, see:
http://pubs.acs.org/cen/acsnews/pdf/8609salary.pdf