Collagen is the most abundant protein family in mammals. Commercial edible 
gelatins are often produced from bovine and porcine skin and bone and consist 
mainly of partially hydrolyzed collagen type 1. The gelatin industry would 
benefit from a sensitive and reliable species detection method to unambiguously 
demonstrate species authenticity of their products. PCR and ELISA could in 
principle be used for this purpose. However, for gelatin, problems associated 
with false-positive and false-negative results, inconsistencies and low 
reactivity of commercially available kits have been observed with regard to 
ELISA and PCR methods. Therefore we developed a selective bottom-up LC-MS 
methodology for quantitative gelatin species determination with a lower limit of 
quantification of 0.05%. The present article describes the validation of this 
method, which was performed according to Good Laboratory Practice, and the 
theoretical justification for bovine and porcine target selection. The validated 
method can be used to determine the purity of gelatin batches with regard to 
bovine and porcine constituents.