This Research Communication reports the physicochemical properties, aflatoxin levels and antibiotic residues in buffalo milk. The milk and feed samples were collected from nine farms in Peninsular Malaysia, with the lactation stage studied in one farm. Buffalo milk composition varied across farms; Petaling Jaya showed high fat and total solids but low protein and solids non-fat (SNF), while Jitra 1 and Seberang Perai 2 exhibited higher protein, casein and SNF. Langkawi and Hulu Langat had higher moisture, ash and lactose levels. Early and late lactation were linked to higher protein and casein. Aflatoxin B1 in feed was undetectable; however, aflatoxin M1, amoxicillin and oxytetracycline were present in milk but below the regulatory limits. These findings indicate that current on-farm management practices are effective in ensuring the safety and quality of buffalo milk, while continuous monitoring remains crucial.
In this work, a novel electrochemical sensor was fabricated for determination of amoxicillin in bovine milk samples by decoration of carboxylated multi-walled carbon nanotubes (MWCNTs) with gold nanoparticles (AuNPs) using ethylenediamine (en) as a cross linker (AuNPs/en-MWCNTs). The constructed nanocomposite was homogenized in dimethylformamide and drop casted on screen printed electrode. Field emission scanning electron microscopy (FESEM), energy dispersive X-Ray (EDX), X-Ray diffraction (XRD) and cyclic voltammetry were used to characterize the synthesized nanocomposites. The results show that the synthesized nanocomposites induced a remarkable synergetic effect for the oxidation of amoxicillin. Effect of some parameters, including pH, buffer, scan rate, accumulation potential, accumulation time and amount of casted nanocomposites, on the sensitivity of fabricated sensor were optimized. Under the optimum conditions, there was two linear calibration ranges from 0.2-10 µM and 10-30 µM with equations of Ipa (µA) = 2.88C (µM) + 1.2017; r = 0.9939 and Ipa (µA) = 0.88C (µM) + 22.97; r = 0.9973, respectively. The limit of detection (LOD) and limit of quantitation (LOQ) were calculated as 0.015 µM and 0.149 µM, respectively. The fabricated electrochemical sensor was successfully applied for determination of Amoxicillin in bovine milk samples and all results compared with high performance liquid chromatography (HPLC) standard method.