Abstract: A simple spectrophotometric method is described for determination of total alkaloids based on the reaction with Bromocresol Green (BCG). A yellow complex forms and is easily extractable by chloroform at pH 4.7. The absorbance of the complex obeys Bear’s law over the concentration range of 4-13 μg atropine per mL of chloroform. This procedure can be carried out in the presence of other compounds without interference.