Fact check: Does doxorubicin has fragmentation ion of 399 in MS?

1. Summary of the results

Based on the available analyses, doxorubicin itself does not have a fragmentation ion of 399 in MS. The main fragmentation ions for doxorubicin are actually 397, 379, 361, and 321 ^[1]. However, it's important to note that a fragmentation ion at m/z 399 does exist, but it belongs to a metabolite of doxorubicin called 7-deoxydoxorubicinol aglycone, observed in negative ionization mode ^[2].

2. Missing context/alternative viewpoints

The original question overlooks several important aspects of mass spectrometry analysis of doxorubicin:

• Multiple fragmentation ions exist for doxorubicin, including 397 and 379 ^[3]
• The presence of metabolites that have different fragmentation patterns
• The importance of ionization mode in MS analysis, as the 399 ion is specifically observed in negative ionization mode ^[2]
• The existence of subsequent fragmentation, as the 399 ion further fragments to m/z 351 ^[2]

3. Potential misinformation/bias in the original statement

The question demonstrates a common oversimplification in mass spectrometry analysis by:

• Assuming a single fragmentation ion can definitively identify a compound
• Not specifying the ionization mode, which is crucial for MS analysis
• Not distinguishing between the parent compound (doxorubicin) and its metabolites, which can lead to misinterpretation of results
• Not acknowledging that mass spectrometry results can vary based on experimental conditions and equipment settings

This type of oversimplification could benefit equipment manufacturers or testing facilities that offer simplified testing services, but might not provide the complete analytical picture needed for thorough research or clinical applications.