C18 synergi fusion rp 80i columns

Carotenoid analyses were conducted using the high-performance liquid chromatography (HPLC) method as detailed previously [41 (link)]. Before analysis, the breastmilk samples were saponified based on the modified method by Macias and Schweigert [43 (link)]. The concentrations of selected carotenoids (β-carotene, lycopene and lutein + zeaxanthin) were determined using a Shimadzu HPLC system (Japan: 2 LC-20AD pumps, CMB-20A controller system, SIL-20AC autosampler, UV/IS SPD-20AV detector, CTD-20AC controller) using C18 Synergi Fusion-RP 80i columns (250 × 4.60 mm, Phenomenex, CA, USA). The concentration of carotenoids was assessed based on standard curves prepared with Sigma Aldrich standards (catalogue numbers: β-carotene C4582, lutein X6250, lycopene L9879, Merck KGaA, Darmstadt, Germany) and expressed in nmol/L.

Breastmilk carotenoids’ (β-carotene, lycopene, and lutein + zeaxanthin) concentration in milk samples was assessed using high-performance liquid chromatography system (HPLC). Milk samples for the analysis were prepared on the basis of the modified method published earlier [12 (link),13 (link)]. Analysis of the studied carotenoids was carried out at a wavelength of 471 nm for lycopene, 450 nm for β-carotene, and 445 nm for lutein + zeaxanthin using the HPLC system (Japan: 2 LC-20AD pumps, CMB-20A controller system, SIL-20AC autosampler, UV/VIS SPD-20AV detector, CTD-20AC controller, Shimadzu, Kioto, Japan) using C18 Synergi Fusion-RP 80i columns (250 × 4.60 mm, Phenomenex, CA, USA). The concentration of individual carotenoids was compared to standard curves prepared with Sigma Aldrich standards (catalogue numbers: β-carotene C4582, lutein + zeaxanthin X6250, lycopene L9879). The concentration of the studied carotenoids was expressed in nmol/L. Lutein and zeaxanthin could not be completely resolved and they were summed; therefore, all references to milk lutein concentration refer to lutein + zeaxanthin.