### ISD

Posted:

**Sun Mar 26, 2017 2:28 am**hello every one I really need a help from you Im using a multi level calibration curve with the internal standard method ( adding equal amount of IS in all the unknown samples ) when I analyse the data to get the unknown concentration of my plasma samples I do the following :

1* find the response ratio ( sample peak / internal standard peak )

2* draw the standard calibration curve and finding the slope and the intercept

3* calculate the concentration for all the unknown samples using the equation

(y=mx+b)

where

y =the response ratio ( sample peak / internal standard peak )

m = slope

b = intercept

x = the unknown concentration

then multiply the x by the dilution factor snice my sample used was 7.5ul and the final volume of preparation is 150ul so I multiply by 20 to get my rea concentration in 7.5ul

my internal standard volume was 15ul

but I Don't included it in my calculation is that right ?. because I SAW my lab mate included it in the calculation to get the unknown conc. like he will take the resulted concentration directly after calculating it from the equation (y=mx+b) and multiply it by 15 divided by 7.5

Im confused

and please can you suggest me a good reference to help me in doing such a calculation because Im in japan and they cant communicate in English with me and this is totally new for me

1* find the response ratio ( sample peak / internal standard peak )

2* draw the standard calibration curve and finding the slope and the intercept

3* calculate the concentration for all the unknown samples using the equation

(y=mx+b)

where

y =the response ratio ( sample peak / internal standard peak )

m = slope

b = intercept

x = the unknown concentration

then multiply the x by the dilution factor snice my sample used was 7.5ul and the final volume of preparation is 150ul so I multiply by 20 to get my rea concentration in 7.5ul

my internal standard volume was 15ul

but I Don't included it in my calculation is that right ?. because I SAW my lab mate included it in the calculation to get the unknown conc. like he will take the resulted concentration directly after calculating it from the equation (y=mx+b) and multiply it by 15 divided by 7.5

Im confused

and please can you suggest me a good reference to help me in doing such a calculation because Im in japan and they cant communicate in English with me and this is totally new for me