Laser Ablation IRMS analyses of 𝛅13C in both solid and liquid foodstuff

Laser ablation (LA) offers speed, high sample throughput, minimal sample preparation and is economical when considering consumables and operating costs. For stable isotope analyses the elemental analyzer (EA) is the standard sample introduction method for solid samples. A few pioneer labs have adopted LA for IRMS analyses and we believe that LA IRMS should become the go-to method for stable isotope ratio measurements. We present a series of sugars/sweeteners made from a variety of plants and a set of vegetable oils extracted from various plans as well, analyzed via LA IRMS. The analytical setup is composed of a Teledyne Photon Machines LSX 213 G2+ 213 nm wavelength laser ablation system connected to a Sercon HS2022 IRMS via a CryoPrep sample preparation module. A specially designed sample chamber was used (isoScell Δ100, Terra Analitic). Split sugar samples were also analyzed via traditional EA IRMS (Sercon), for inter-instrument comparison. Cellulose (IAEA CH6) was used as reference in both instruments. LA IRMS offers accurate and precise determination of 𝛅13C in most solid, organic matrices with the advantage of drastically reduced sample preparation and overall analytical costs. Given the minuscule amount of sample removed through ablation repeat analysis is always an option with LA. A single sugar crystal is enough for more than ten ablations and the standard deviation in our tests was 0.03‰. Liquid samples are just as easy to analyze!