A mild mixed-solvent of n-hexane/isopropanol is proposed for extracting total mineral oil hydrocarbons (MOH) from commercial milk powder products. Unlike acid-hydrolysis, the mixed-solvent extraction was performed at ambient temperature and the low-boiling-point hydrocarbons were retained to the greatest extent. After extraction, total MOH was determined by on-line liquid chromatography-gas chromatography with a flame ionization detector (LC-GC-FID). The validation of the proposed extraction method revealed a recovery efficacy of 83.0–107.5% and a limit of quantification of 0.5 mg/kg. Then, the total MOH in ten commercial milk powders was determined and mineral oil saturated hydrocarbons (MOSH)/polyolefin oligomeric saturated hydrocarbons (POSH) were found to be within the range of 0.61–5.46 mg/kg. The comparison of the total and surface MOSH/POSH indicated that a major part of the contamination was derived from sources before packaging. The present study provides a robust method for the extraction and determination of total MOH in milk powders.

n的温和混合溶剂提议使用正己烷/异丙醇从商业奶粉产品中提取总矿物油烃（MOH）。与酸水解不同，混合溶剂萃取在环境温度下进行，并且最大程度地保留了低沸点烃。提取后，通过在线液相色谱-气相色谱-火焰离子检测器（LC-GC-FID）测定总MOH。所提方法的验证显示回收率为83.0–107.5％，定量限为0.5 mg / kg。然后，测定了十种市售奶粉中的总MOH，发现矿物油饱和烃（MOSH）/聚烯烃低聚饱和烃（POSH）的范围为0.61-5.46 mg / kg。对总和表面MOSH / POSH的比较表明，大部分污染来自包装前的污染源。本研究为乳粉中总MOH的提取和测定提供了一种可靠的方法。