Gpc malls

GPC-MALLS (Wyatt Technology Corporation, Santa barbara, CA, USA) was employed for evaluating the distributions of molecular weight and mass of UPF. This system employs a Waters 2690D separations module, a Waters 2414 refractive index detector (RI) and a Wyatt DAWN EOS MALLS detector. Ten milligrams of UPF was dissolved in 1 mL of 0.1 M NaNO₃ solution that was rolled overnight so that the entire amount was dissolved. Post a four-fold dilution, a 0.45 μm nylon filter (Millipore Corp., Billerica, MA, USA) was utilized to filter the solution of which 100μL was injected. A series of OHpak SB-805 HQ, OHpak SB-806 HQ, and OHpak SB-803 HQ columns were used. The collection and analysis of data was done using Astra 4.90.08 software (Wyatt Technology Corporation, Santa barbara, CA, USA).

The homogeneity and molecular weight of SIP were measured using a gel permeation chromatography-eighteen angles laser light scattering instrument (GPC-MALLS) (Wyatt Technology Corporation, Santa Barbara, CA, United States). In brief, 10 mg of SIP was placed in 1 mL of .1 M NaNO₃ solution in a small beaker, which was then placed on a magnetic stirrer (Crystal Technology & Industries, Dallas, TX, United States) and stirred overnight to dissolve the SIP. The SIP sample was diluted fourfold with .1 M NaNO₃ solution and then filtered through a .22-μm nylon filter (Millipore Corp., Billerica, MA, United States). The filtered sample was then subjected to gel permeation chromatography using a GPC-MALLS system. The samples were resolved by three tandem columns (300 × 8 mm, Shodex OH-pak SB-805, 804 and 803; Showa Denko K.K., Tokyo, Japan) with .1 M NaNO₃ solution used as a mobile phase under a flow rate of .4 mL/min. The data were collected and analyzed with the Astra 6.1 software (Wyatt Technology Corporation, Santa Barbara, CA, United States).