18933
We report an approach based on a combination of inductively coupled plasma mass spectrometry and X - ray photoelectron spectroscopy for quantitative analysis of the role played by Br ( - ) ions in the synthesis of Pd nanocrystals .
 Chemical: Br ( - ); Chemical: Pd
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: Br ( - ), Pd 
Answer:
 Chemical: Br ( - ); Chemical: Pd