2.1. Materials and Reagents
All lactating mothers in this study were obtained from the Maternal and
Child Health and Family Planning Service Center of Jiangning District,
Nanjing, Jiangsu Province, China. From November 2018 to January 2019,
breast milk of 121 eligible healthy lactating mothers was included in
this study. The project has been approved by the Human Research Ethics
Committee of Nanjing Medical University and registered as
ChiCTR1800020179 in clinicaltrials.gov. Each participant provided oral
and written informed consent. Inclusion criteria: (1) 20-40 years old
healthy lactating mothers, 30-50 days postpartum exclusive
breastfeeding; (2) singleton pregnancy, full-term delivery (≥ 37 weeks
of gestation), birth weight ≥ 2500 g, ≤ 4000 g infants. Mothers with any
infectious disease, severe malignant disease, malnutrition, or mental
illness; people diagnosed with breast diseases such as mastitis; or
people with pregnancy complications such as gestational hypertension and
diabetes were excluded. Mothers who had a history of drinking and
smoking during pregnancy and lactation, vegetarians, mothers who
consumed fatty acid supplements during lactation, or who participated in
other studies in the past 30 days were also excluded.
The mixed TAGs standards (8:0, 10:0, 12:0, 14:0 and 16:0, 17811-1AMP)
were purchased from Sigma-Aldrich Limited (Shanghai, China). High
performance liquid chromatography grade n -hexane, acetonitrile,
and iso -propanol were purchased from Shanghai Bailingwei
Technology Co., Ltd. (China, Shanghai). Ammonia, ethanol, anhydrous
ethyl ether (boiling point of 30 to 60 ℃), and petroleum ether were
purchased from Chemical Reagent Co., Ltd. (Shanghai, China).