Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The influence of heating time on the amounts of umbelliferone derivatives in phosphoric buffer (pH 5; a), phosphoric buffer (pH 9; b), acetic buffer (pH 5; c), acetic buffer (pH 9; d), ammonia buffer (pH 5; e), and ammonia buffer (pH 9; f) solution of umbelliferone, all heated under reflux. Numbers under bars correspond to compound numbers reported in Supplementary Scheme 1
