Star chromatography workstation software

In a glass tube, 100 µL of an ethanolic solution with 3540 mg·L⁻¹ of internal standard (4-nonanol, Merck, Darmstadt, Germany) was added to 5 mL of mead.
A Chrompack GC CP-9000 gas chromatograph equipped with a split/splitless injector, a flame ionisation detector (FID) and a capillary column CP-Wax 57 CB (50 m × 0.25 mm; 0.2 μm film thickness) was used. The temperatures of the injector and detector were both set to 250 °C, and the split flow was 15 mL min⁻¹. The column temperature was initially held at 60 °C for 5 min, then programmed to rise from 60 °C to 220 °C at 3 °C·min⁻¹ and finally maintained at 220 °C for 10 min. The carrier gas was special helium 4× (Praxair, Danbury, CT, USA) at a flow rate of 1 mL·min⁻¹ (125 kPa at the head of the column). The analysis was performed by the injection of 1 μL of sample. The major compounds in the samples were determined directly by the internal standard (4-nonanol) method, taking into account the relative response of the detector for each analyte, with Star–Chromatography Workstation software, version 6.41 (Varian). The identification was performed by comparing test compound retention times with those of pure standard compounds.

Evaluation of LLLT-dependent changes in the nitric oxide availability was analyzed by assessing the PRMT-L-Arg/ADMA-DDAH axis. Plasma levels of L-arginine (a substrate for NO synthase) and its methyl derivatives (asymmetric and symmetric dimethylarginine—ADMA, SMDA, competitive inhibitors of the nitric oxide synthase) were measured by a high-performance liquid chromatography (HPLC). Plasma samples and standards extracted a solid-phase extraction cartridge with SCX50 columns (Varian Inc., USA). Eluates were derivatized with o-phthaldialdehyde (OPA) and separated by isocratic reversed-phase chromatography on a Symmetry C18 column (150 × 4.6 mm, 5 μm particle size; Waters Corp., USA). Potassium phosphate buffer (50 mM, pH 6.6) containing 12% acetonitrile was used as the mobile phase at a flow rate of 1.1 ml/min. Fluorescence detection was performed at the excitation 340 nm and emission 450 nm wavelengths. The test was performed on a computer controlled by Star Chromatography Workstation software (version 6.3); the device was made by Varian (New York, USA).

Total phenolic content was determined as previously described by Mamelona et al. using the Folin–Ciocalteu reagent [48 (link)]. The samples were analyzed spectrophotometrically at 760 nm and the results were presented as mg gallic acid equivalent (GAE) per 100 g dry weight (DW) sample (mg GAE/100 g). All samples were reported in triplicates.
Major phenolic compounds were determined by high-performance liquid chromatography (HPLC) analysis applying the method reported by Katsarova [49 ]. HPLC system (Varian Inc., Agilent, Walnut Creek, CA, USA) equipped with ProStar 230 solvent delivery module and Hitachi C18 AQ (250 mm × 4.6 mm, 5 μm) column was used. The system of solvents included deionized water adjusted to pH 3.7 with phosphorus acid and acetonitrile in gradient state. Star Chromatography Workstation software (version 6.30) (Agilent, Walnut Creek, CA, USA) was used for the analyses. Chlorogenic acid and caffeic acid were detected at 360 nm. Results were calculated with standard curves for each analytical standard and expressed as mg/100 g DW.