What does it mean? First separate the reference into its component parts:
Brown, A.S.; Milton, M.J.T.; Cowper, C.J. J. Chromatogr. A. 2004, 1040, 215-225.
Brown, A.S.; Milton, M.J.T.; Cowper, C.J. | J. Chromatogr. A. | 2004, | 1040, | 215-225.
Note that in chemistry bibliographies the article title is usually not given. References generally do not contain URLs to an article found on the Web. This is because the reference is meant to be a persistent starting point, and direct web links have a relatively short lifespan and most articles are behind subscription paywalls. It's up to the reader to figure out on his own how to get the article from the information given in the reference.
So -- how do you do that? Go to the next page to find out.