The sample was transferred into screw-capped conical vials and 5 μl were injected onto the LC-MS/MS system.
Serial dilutions of pure H2 gas were prepared in 25-mL gas-tight vials, and identical volumes were injected into the gas chromatograph: data from three replicates were used to draw the H2 calibration curve.
After centrifugation, the supernatant was transferred to an autosampler vial and 10 μL were injected into the HPLC-MS/MS system (API 4 000 mass spectrometer, Applied Biosystems, Darmstadt, Germany) equipped with an Agilent 1100 HPLC System (Agilent Technologies, Waldbronn, Germany).
Three to six nodules were placed into 3 ml glass vials sealed with rubber cap and immediately 0.15 ml acetylene were injected into the vials to incubate nodules in the presence of 10% (v/v) acetylene.
To assess the dosing accuracy of each insulin pen used in the study, two insulin doses were injected into vials with both application strategies (1 × 18 IU and 9 × 2 IU), and then each dose was weighed with a microbalance (Sartorius, Göttingen, Germany).
The reconstituted extracts were transferred into autosampler vials and 50 μl of each sample were injected on to the LC column (equivalent to 75 μl of plasma sample).
NO standards and samples were injected directly into the vial and provided good baseline stability and a limit of detection of 0.18 μl/L in the vial.
For isotopic analysis, 12 mL of headspace air were injected into 12 mL glass vials (Exetainer, Labco Ltd ,High Wycombe, UK) containing CO2-free air.
Blood culture specimens were injected into BACTEC Plus culture vials for aerobic and anaerobic cultures and processed in BACTEC 9240 blood culture system (Becton Dickinson, Cockeysville, MD).
