What is a key feature of a mass spectrum that helps in identifying molecular weight?

What is a key feature of a mass spectrum that helps in identifying molecular weight?

• A. The height of all peaks
• B. The molecular ion peak furthest to the right
• C. The area under each peak
• D. The shape of the spectrum

Answer: (B)

In mass spectrometry, the molecular ion peak is significant because it represents the intact molecular weight of the compound being analyzed. The molecular ion peak is typically the highest m/z (mass to charge ratio) value observed in the spectrum, and it is usually found furthest to the right on the mass spectrum graph. This peak indicates the molecular weight of the analyte before any fragmentation occurs, providing crucial information for its identification. The other features of the spectrum, such as peak height, area under the peaks, and the overall shape, can provide additional information about the relative abundance of ions or fragmentation patterns but do not directly indicate the molecular weight. The molecular ion peak is therefore essential for determining the molecular weight of the compound in question.

In mass spectrometry, the molecular ion peak is significant because it represents the intact molecular weight of the compound being analyzed. The molecular ion peak is typically the highest m/z (mass to charge ratio) value observed in the spectrum, and it is usually found furthest to the right on the mass spectrum graph. This peak indicates the molecular weight of the analyte before any fragmentation occurs, providing crucial information for its identification.

The other features of the spectrum, such as peak height, area under the peaks, and the overall shape, can provide additional information about the relative abundance of ions or fragmentation patterns but do not directly indicate the molecular weight. The molecular ion peak is therefore essential for determining the molecular weight of the compound in question.