Development and validation of a simple and Robust LC-MS/MS method for the determination of Tutin in honey and its application to market samples from the United Arab Emirates

Tutin is a plant-derived neurotoxin that can contaminate honey when honeybees collect honeydew excreted by insects feeding on the tutu plant, which is native to New Zealand. A simple LC-MS/MS method combined with QuEChERS extraction was developed and validated for the determination of Tutin in honey. Chromatographic separation was achieved on a C18 column using 10 mM ammonium acetate in water/acetonitrile (60:40, v/v) under isocratic elution at 0.200 mL/min, with a total run time of 4.0 min. MS/MS detection was performed in negative electrospray ionization mode using the acetate adduct [M + CH₃COO]⁻ at m/z 353.03, with m/z 153.03 and m/z 138.92 selected as the quantifier and qualifier ions, respectively. The method showed linearity over 0.005-1.000 µg/mL (R² = 0.9988), with LOD and LOQ values of 0.014 and 0.0425 mg/kg, respectively. The method exhibited excellent accuracy (recoveries 91-94%) and precision (RSD ≤ 8%), with an acceptable matrix effect (-12%) and confirmed stability for up to 48 hours under bench-top conditions. Application of the method to 35 honey samples from Australia and New Zealand collected from UAE markets showed Tutin-related responses in five Manuka honey samples originating from New Zealand, with the highest quantifiable level being 0.0449 mg/kg, below the 0.7 mg/kg regulatory limit set by Food Standards Australia New Zealand (FSANZ). The study provides a practical method for routine monitoring of Tutin in honey and preliminary UAE market-surveillance data for imported honey products.