AbstractCollagen extraction from bones or dentine, commonly used for radiocarbon (¹⁴C) dating and stable carbon and nitrogen isotope (δ¹³C and δ¹⁵N) analyses, involves the dissolution of the bioapatite of skeletal elements. This fraction is typically disposed of during pretreatment. Here, we test the possibility of utilising this dissolved mineral solution for analysis of the bioapatite zinc isotope composition (δ⁶⁶Zn). Bioapatite δ⁶⁶Zn is a novel trophic level indicator similar to collagen δ¹⁵N but with isotopic fractionation independent from nitrogen, thus providing additional dietary information. We tested ways to minimise Zn contamination of the dissolved mineral phase during collagen extraction. We then used archaeological bone samples from Ain Difla (Jordan) and Ranis (Germany) to compare δ⁶⁶Zn values of dissolved bioapatite following our collagen extraction protocol with δ⁶⁶Zn values from the same sample material dissolved in a metal-free cleanroom. Our results demonstrate that with only minor adjustments to minimise Zn contamination, the dissolved mineral solution from collagen extraction protocols commonly employed for ¹⁴C dating and (palaeo)dietary analysis can be used for additional δ⁶⁶Zn analyses even when collagen extraction does not take place in a cleanroom. Our protocol allows us to gain an additional dietary proxy to complement δ¹⁵N trophic level interpretations and perform more robust (palaeo)ecological investigations without further destructive sampling.