I am trying to repeat an experiment conducted by FDA on Malachite Green (MG).
According to this paper,
Prepare a series of LC calibrants by aliquoting into individual 15 mL graduated glass or disposable polypropylene centrifuge tubes, 50 µL, 100 µL, and 200 µL of the 0.1 µg/mL MG2 solution and 50 µL and 100 µL of the 1.0 µg/mL MG1 solution. Dilute each to 5.0mL with (1:1 vol) acetonitrile/ammonium acetate buffer (mobile phase A), vortex mix or stopper and invert to mix thoroughly. Based on a 5 g sample weight, these solutions will generate standards with concentrations of 1, 2, 4, 10 and 20 ng/g of MG.
If I am not wrong, Malachite Green used in this paper is from the salt, Malachite Green Oxalate.
- Is Acetonitrile used here as a pH buffer?
- What is the role of Ammonium acetate?
If I plan on using Raman Spectroscopy to detect MG in my samples, shouldn't I be using the pure forms of MG as my reference signal? If so, wouldn't the addition of these two chemicals affect my readings?