In this study, an simultaneous LC-MS/MS multi-residue analytical method was developed and validated for the residues of six neonicotinoid insecticides (acetamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, and thiamethoxam) in honey. Sample preparation included a combination of QuEChERS extraction kit and liquid-liquid extraction method to effectively extract pesticide components from the honey matrix and optimized analytical conditions to achieve high sensitivity and selectivity. The limits of detection (LOD) and the limits of quantitation (LOQ) were set in the range of 6-15 ng/mL and 19-44 ng/mL, respectively and the correlation coefficient (R²) was greater than 0.99, confirming good linearity. In addition, the intra-day recoveries for each pesticide were 75-104%, and the coefficient of variation (CV) was less than 20%, which met the guideline recommended by the Ministry of Food and Drug Safety. The LC-MS/MS method developed in this study is expected to be used as a multi-residue analysis method for 6 neonicotinoid pesticides in honey.

Learning and memory are essential for animals like honey bee, in which foragers leave their nest to collect food and then successfully learn to navigate back to colony. Chronic environmental exposure of neoniconitiod highly affect pollinators like honey bee. We investigated the effect of neonicotinoid, thiacloprid and imidacloprid on learning, memory and mortality of pollen foragers based on their toxicity level. Individual Pollen foragers Apis mellifera were trained using a proboscis extension proboscis. We used three treatments: 50% sugar solution, 50% sugar contaminated thiacloprid and imidacloprid as unconditioned stimulus and 2M 1-nonanol as conditioned stimulus. Our result shows that there is no significant difference between control and thiacloprid treatment both in learning and mortality of honey bee. But we found difference in memory between subjects exposed to control and thiacloprid contamination. Whereas imidacloprid contamination significantly lowered learning, eradicate memory retention and higher mortality of honey bee. Even thiacloprid and imidacloprid are in the same chemical class of Neonicotinoid insecticides, their toxic level would be different resulting in differential ecological impact to honey bee colony.