Determination of 87Sr/86Sr isotopic ratio in olive oil and pomace using multicollector-ICPMS; analysis of pomace residues as a simpler approach for determination of 87Sr/86Sr ratio in olive oil with low Sr content

This study presents an analytical procedure for measuring the 87Sr/86Sr isotopic ratio in olive oil and pomace using multicollector-inductively coupled mass spectrometry (MC-ICPMS). The developed method combines liquid-liquid extraction with acid solution degradation of organic residues extract by dry ashing oxidation H2O2 HNO3. enabled ratios to be obtained Sr content as low 0.2 ng g−1, a precision 54 ppm. method’s validity was confirmed interlaboratory comparison NIST SRM 2387, providing first data on its elemental (2380 ± 230 g−1; n = 10), composition (0.70908 0.00004; 14). applied samples, showing that they have identical ratio, which consistent determined soils from same orchards. results thus revealed can both used geographical traceability studies oil, means that, instead processing large volume characteristic signatures more easily analyzing small quantities centrifuging oil.