Mds sciex analyst qs software

For LC-MS, MG decolorization was performed at 25°C in water instead of buffer. Aliquots (2 μL) were injected into an HPLC system (Agilent 1200 Series, equipped with a Phenomenex Luna C-18 analytical column of 2.0 mm x 150 mm length and 3 μm particle size) coupled with Agilent 6224 Accurate-Mass Time of Flight (TOF) MS. The compounds were resolved by using solvent A: 5 mM ammonium acetate supplemented with 0.5% formic acid and solvent B: acetonitrile. The flow rate was kept at 0.2 mL min^-1. A linear gradient was set as follows: t = 0–2, A = 95; t = 4–5, A = 40; t = 7–11, A = 10; t = 12–15, A = 95. The column effluent was introduced into the electrospray ionization source of the mass spectrometer in positive ion mode. The MS parameters were as follows: capillary voltage 3.5 kV; nebulizer pressure 50 psi; drying gas flow 11 L min^-1; drying gas temperature 360°C; fragmentor voltage 130 V. LC-TOF MS accurate mass spectra were recorded across the range 70–400 m/z. Data processing was carried out with Applied Biosystems/MDS-SCIEX Analyst QS software (Frankfurt, Germany) with accurate mass application-specific additions from Agilent MSD TOF software. Accurate-mass internal mass calibration was performed automatically using a dual-nebulizer ion source. The reference masses were 121.0509 m/z and 922.0098 m/z.

Decolorization of MG was carried out at 30 and 60 °C. The starting reaction mixture contained 50 mM citrate-phosphate buffer (pH 6.0), 100 mg/L MG and 3 U/mL laccase. The mixture with heat-inactivated laccase was used as the negative control. After decolorization, the reaction mixtures were subjected to UV-visible analysis with a UV-Vis spectrophotometer (U-2910, Hitachi, Japan). Decolorization efficiency was monitored at 618 nm and calculated with the following formula: $$\mathrm{Decolorization}\mathrm{efficiency}(\%)=\frac{\mathrm{A0}-\mathrm{A1}}{\mathrm{A0}}\times 100$$ where A₀ and A₁ are the absorption of MG before and after laccase treatment, respectively.
Degradation products were identified with liquid chromatography-time of flight mass spectrometry (LC-TOF MS) as previously described^{13 (link)}. Briefly, an HPLC system (Agilent 1200 Series, equipped with a Phenomenex Luna C-18 analytical column) coupled with Agilent 6224 Accurate-Mass TOF MS was used. The column effluent was introduced into the electrospray ionization source of the mass spectrometer in positive ion mode. LC-TOF MS accurate mass spectra were recorded across the range 70–400 m/z. Data processing was carried out by using Applied Biosystems/MDS-SCIEX Analyst QS software (Frankfurt, Germany) with accurate mass application-specific additions from Agilent MSD TOF software.