A method was developed for simultaneous measurement of the levels of vitamins A, D3, K2, E, and β-carotene in infant formula milk powder using ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The calibration curves for the five fat-soluble vitamins showed good linearity within the concentration range of 1–800 ng/mL. The average recoveries at three spiked levels were between 92.0% and 108.0% with relative standard deviations (RSDs) ranging from 0.4% to 2.6%. The limits of quantification (LOQs) of this method were 12.5–125 μg/100 g. The proposed method was characterized by simple sample pre-treatment, high quantitative sensitivity, and good accuracy and precision.

In recent years, with the growth of dairy consumption, dairy quality and safety have become a matter concerning people’s health and safety. However, poisoning incidents often occurred because of dairy products contaminated by enterotoxin-producing strains of Staphylococcus aureus. Thus risk assessment of Staphylococcus aureus is important for raw milk as the source of dairy products. Based on the principles and guidelines of the Codex Alimentarius Commission for microbial risk assessment, this paper reviews the studies in the field of risk assessment of Staphylococcus aureus in raw milk, including hazard identification, hazard characterization, exposure assessment and risk characterization. Through the mature cases of quantitative risk assessment, we introduce the basic framework for quantitative risk assessment of Staphylococcus aureus in raw milk and propose that more intensive studies are needed to construct a prediction model of enterotoxin and that systematic monitoring and microbial risk assessment of raw milk from pasture to table is necessary for providing basic information for safety monitoring and early warning security system of raw milk and dairy products.