Agilent 6890 series gc system

Determinations of total essential oil content were carried out according to Analytica-EBC 7.10 method [17] . Briefly 50 g of dry and ground hop coins were mixed with 1000 mL of deionized water and steam distilled for 3 h. Identification and quantification of components of hop essential oil were carried out according to Analytica-EBC 7.12 method [18] . Then 0.2 mL of collected oil was diluted with 5 mL of hexane and separated by GC analysis. Agilent 6890 series GC system equipped with the flame ionization detector and HP-1 capillary column (30 m × 0.25 mm, 25 µm, Agilent, Santa Clara, CA, USA) and nitrogen 5.0 as a carrier gas with a flow rate 0.6 mL min -1 was used. Solution (23) (link). All solvents were of analytical grade or higher purity purchased by Sigma-Aldrich, Germany. Following the methodology and using standards purchased at Sigma-Aldrich, the following components were determined; myrcene, trans o-cymene, linalool, methyl caprylate octanoate, geraniol, methyl-nonyl-keton (undecanon), delta-cadinene T, methyl-deca-4-enoate, methyl-deca-4dienoate, geranyl acetate, beta-caryophyllene, alpha-humulene, farnesene, germacrene-D, beta-selinene, alpha-selinene, bisabolene, caryophyllene epoxide, humulene epoxide-2, humulene epoxide-1, Iso-butyl-iso-butyrate, limonene, 2-nonanone (methyl-heptyl-keton), alpha-pinene, beta-pinene, and farnezol. LOQ of the method was 0.1 rel.%.

Polymer production was evaluated by gas chromatography following a protocol which has been described by others (Braunegg et al., 1978; Jung et al., 2009) . Cell pellets were collected from flask culture after a 3-day incubation by centrifuging at 4,000 g for 20 min, then washed twice with distilled water, and finally dried at 100°C overnight. The dried cell weight (DCW) was recorded before methanolysis in 2 ml chloroform and 1 ml PHB solution containing 8 g benzoic acid l -1 as an internal standard and either 30% sulfuric acid (for PHB) in methanol.
The reaction was carried out at 96°C for 6 h, cooled, and then 1 ml of water was added, the mixture was vortexed, and the solution was allowed to separate into two phases. 1 µl of the chloroform phase was taken for analysis by GC as previously described (Jung et al., 2009). The samples were injected into Agilent 6890 series GC system with a DB Wax column (30 m x 0.53 mm, film thickness 1 µM, J & W Scientifics), which is located in the Department of Chemical Engineering. The oven program was set as following: initial temperature was set at 80ºC for 5 min, then ramped to 230ºC at 7.5ºC/min, and continued to ramp to 260ºC at a faster rate 10ºC/min followed by maintaining that temperature for 5 min.