추천버퍼조건(Positive 모드)
• Ammonium formate or acetate (2-10 mM optimum, can see suppression effects over 20 mM).
• Acetic acid at 0.1 - 1.0 %
• 0.1% TFA (good for chromatography)에서 Formic acid 는 약 0.1% 가 적당함
Probe 온도조건
• 대부분의 분석물질은 약 150°C 가 한계.
• Solvent 와 flow rate 에 따라 최저와 최고 온도를 적절하게 조절함.
Compounds That Cause Sensitivity Suppression
• Salts can interfere with ionization and can cluster to complicate spectrum (but also aid in identification).
• Strong bases or quaternary amines can interfere with positive mode analytes, e.g. Triethylamine (TEA)
• Acids - Sulfuric/Sulfonic acids and TFA interfere in negative mode experiments.
• Phosphate buffer and non-volatile ion pairing agents (e.g. SDS) can cause severe suppression and complex spectra.
• Dimerization ([2M+H]+) can occur at high concentration, leading to non-linearity during Quantitation.
• Dimer Signal at m/z = (MW*2)+1 can cause non-linearity at high concentrations.