Cavaliere Chiara, Capriotti Anna Laura, Foglia Patrizia, Piovesana Susy, Samperi Roberto, Ventura Salvatore, Laganà Aldo
Dipartimento di Chimica, Università di Roma "La Sapienza", Rome, Italy.
J Sep Sci. 2015 Oct;38(20):3599-606. doi: 10.1002/jssc.201500549. Epub 2015 Sep 15.
Natural estrogens are synthesized by mammals in different amounts depending on the developmental stage and pregnancy/lactation period, and they may pass into milk, where they are mostly present as glucuronated and sulfated forms. In modern dairy practices, about 75% of milk is produced from pregnant cows; therefore, the amount of hormones that may pass into milk could be of concern. While estrogen determination in milk has been investigated in depth, the individual determination of estrogens and their conjugated forms in dairy products has not been fully addressed. The aim of this work was to develop and assess a sensitive method, using the peculiar retention properties of graphitized carbon black, to extract natural free estrogens and their major conjugated metabolites, without any enzymatic cleavage, from yogurt, cheese, and butter. The free and conjugated estrogens were eluted in two distinct fractions from the solid-phase extraction cartridge and analyzed separately by ultra high performance liquid chromatography coupled to tandem mass spectrometry. Recoveries were higher than 80% for all the three sample typologies. The highest matrix effects were observed for butter, which was richest in lipid content, but was below 30%. A survey on some commercial dairy products suggests that production processes decreased estrogen content.
天然雌激素由哺乳动物根据发育阶段以及怀孕/哺乳期的不同而合成出不同的量，并且它们可能进入乳汁中，在乳汁中它们大多以葡萄糖醛酸化和硫酸化形式存在。在现代乳制品生产中，约75%的牛奶来自怀孕的奶牛；因此，可能进入牛奶中的激素量可能令人担忧。虽然对牛奶中雌激素的测定已进行了深入研究，但乳制品中雌激素及其结合形式的单独测定尚未得到充分解决。这项工作的目的是开发并评估一种灵敏的方法，利用石墨化炭黑独特的保留特性，在不进行任何酶解的情况下，从酸奶、奶酪和黄油中提取天然游离雌激素及其主要结合代谢物。游离和结合雌激素从固相萃取柱中以两个不同的馏分洗脱，并通过超高效液相色谱-串联质谱法分别进行分析。所有三种样品类型的回收率均高于80%。在脂质含量最高的黄油中观察到最高的基质效应，但低于30%。对一些商业乳制品的调查表明，生产过程降低了雌激素含量。
