An extraction method for the determination of the Rose Bengal content in the preparations of Rose Bengal labelled with131I

The paper describes an extraction radiometric method for the determination of Rose Bengal content in the radiopharmaceutical preparations of Rose Bengal labelled with¹³¹I. Two methods have been studied. The first one is based on the addition of an excess and substoichiometric amounts of Septonex /carbetoxypentadecyltrimethylammonium bromide/ to the sample of Rose Bengal-¹³¹I and on the activity measuring of the chloroform extracts. The second method is based on the extraction of Rose Bengal-¹³¹I with substoichiometric amount of Septonex from the sample of Rose Bengal-¹³¹I and the sample of Rose Bengal-¹³¹I diluted with a known amount of an inactive Rose Bengal preparation.