Agilent openlab software

HPLC analytical finish was used to determine the dissolved/supersaturated, un-dissolved/precipitated, as well as the partitioned amount of MSC-A during in vitro transfer model and in vitro DTPS experiments. Therefore, an Agilent 1260 Infinity series HPLC system (Agilent Technologies, Santa Clara, CA, USA) was employed. The HPLC system consisted of a Binary Pump, an Agilent Autosampler, a Thermostat, a Thermostated Column Compartment, and an Agilent Diode Array Detector VL. The Agilent OpenLAB software (Agilent Technologies, Santa Clara, CA, USA) was employed. The method parameters used for drug quantification are summarized in the Supplementary Materials. LOD and LOQ determinations yielded appropriate results. Calibration curves were linear, with an R2 of 0.9999.

Five mL of venous blood was collected from all the women, after overnight fasting, into EDTA-containing tubes. The detailed procedures for blood processing and analysis have been described previously [28 (link)]. Briefly, within 4 h of blood drawing, blood samples were centrifuged, to obtain aliquots of plasma and erythrocytes. The erythrocytes were washed out with 0.9% (w/v) NaCl solution. These aliquots were stored at −20 °C at the local hospitals, for about 10 days, before being sent back on dry ice to the central laboratory, and then stored in a −80 °C freezer and analyzed within two months. Fatty acid concentrations were determined by Agilent 6890N capillary gas chromatography (Agilent Technologies, Palo Alto, CA, USA). Individual fatty acids were identified by comparison with reference standards. The data were recorded using the Agilent Open LAB software (Agilent Technologies, Santa Clara, CA, USA). The concentrations of DHA were expressed as relative concentrations (weight percent of total fatty acids, wt. %).

The extraction and derivatization of total lipids in plasma and erythrocyte samples were carried out using a modified method of Folch et al. [13 (link)]. The internal standard solution containing methyl undecanoate (C11:0) was added to the samples, and mixed with boron trifluoride and methanol. This mixture was heated at 115 °C for 20 min. After cooling to room temperature, the mixture was extracted with n-hexane. The n-hexane containing methyl esters of total lipids were analyzed by an Agilent 6890N gas chromatography (Agilent Technologies, Palo Alto, CA, USA) equipped with a flame ionization detector at 280 °C and a capillary column (CP-Sil 88, 50 m, 0.25 mm ID, 0.20 μm film thickness). The injector was set as a split mode at 250 °C, with the split ratio of 1:5. The oven temperature was programmed as follows: ramping from 120 °C to 166 °C at 2 °C/min, and holding at 166 °C for 10 min; then ramping to 200 °C at 2 °C/min and holding at 200 °C for 10 min. Individual fatty acids were identified against the reference standards. The data were collected and processed using Agilent OpenLAB software (Agilent Technologies, Santa Clara, CA, USA). Both absolute concentration (μg/mL) and the relative concentration (weight percent of total fatty acids, wt. %) of DHA were calculated.