Aflatoxin Analysis of Mutant Koji Extract

The cell free supernatant (two hundred ml) produced by mutant Koji strain M-100(6) was extracted (using separating funnel) with two hundred ml of chloroform. The organic solvent (chloroform) was evaporated using rotary evaporator. The residue was dissolved in methanol (two ml), filtered through membrane filter (0.45 μm, nylon membrane, Millipore) and subjected to aflatoxins analysis using LC-MS (Quadrupole Linear Ion Trap Mass Spectrometer Finnegan LTQ XL hyphenated with Surveyor Plus LC system, manufactured by Thermo Fisher Scientific, USA. Samples were analyzed using previously developed analytical method [51 (link)]. The samples were initially infused to the Mass Spectrometer by direct syringe pump through positively ionized electro spray ionization (ESI) probe: spray voltage 5 kV, sheath gas flow rate 70 arbitrary units, auxiliary gas flow rate 20 arbitrary unit, capillary temperature 335 °C, capillary voltage 45 V, and tube lens voltage 110 V.