Spectrophotometer is a commonly used and basic analytical technique 
that can be used for both quantitative and qualitative examination in 
chemical, pesticides and other materials. In this work, it was studied that 
spectral-density (S-D) curve, calibration density (C-D) curve and 
quantification limits for fipronil and neonicotinoids insecticides in 
acetonitrile solvent on UV-Vis Spectrophotometer (Thermo Corporation, 
Nicolet, evolution 100) were maximum absorption (λ max) equal 208, 256, 
269 and 246 nm for fipronil, thiamethoxam, imidacloprid and 
acetamiprid, respectively. The slope and R2 were 0.059 and 0.9545 for 
fipronil, 0.044 and 0.9989 for thiamethoxam, 0.046 and 0.999 for 
imidacloprid and 0.249 and 0.9996 for acetamiprid, respectively. The 
limit of blank (LOB), limits of detection (LOD), and quantification 
(LOQ) were found to be 0.0614, 0.0623 and 0.906 μg mL-1 for fipronil, 
0.0613, 0.062 and 0.0865 μg mL-1 for thiamethoxam and 0.0946, 0.954 
and 0.123 μg mL-1 for imidacloprid and 0.0478, 0.0489 and 0.158 μg 
mL-1 for acetamiprid, respectively.