Mass Spectrum Analysis: Identifying Mass & Charge

[mikeb94]

Hello everyone,

I'd like to know how to identify the charge and the mass in a mass spectrum. How do I get the mass corresponding to a peak. I know how they are related

p=\frac{m}{z}
p_1=\frac{M_r+z_1}{z_1}
p_2=\frac{M_r+(z_1-1)}{(z_1-1)}
z_1 =\frac{p_2-1}{p_2-p_1}
M_r = \frac{1}{\frac{1}{p_1-1}-\frac{1}{p_2-1}}

but do I need a reference mass for a mass-to-tof calibration or?

 

[mikeb94]

sorry, didn't know how to use Latex here ;)
$$
p=\frac{m}{z}$$ $$
p_1=\frac{M_r+z_1}{z_1}$$ $$
p_2=\frac{M_r+(z_1-1)}{(z_1-1)} $$ $$
z_1 =\frac{p_2-1}{p_2-p_1} $$ $$
M_r = \frac{1}{\frac{1}{p_1-1}-\frac{1}{p_2-1}}$$

 

[berkeman]

Welcome to the PF.

Could you define your terms, and give us a diagram of the path of the particles as they pass through the fields?

Also, is this for a schoolwork assignment?

 

[mikeb94]

schoolwork would be nice, seminar for graduated ;)
mass $$m$$
charge $$z$$
peak in spectrum $$p_i$$
original mass of ion $$M$$

What I essentially wanted to ask: Do you need a reference mass (e.g. a bucky ball or a carbon atom) with a known mass for measuring a spectrum of a new molecule or can you gain this information only by some calculation (as mentioned above) out of a spectrum without any reference?