Not very much. Your MS will get a little dirty like it would with any other sample. The main issue with using phosphate buffers is that they are non-volatile and clog up the MS. The phosphate buffer will accumulate around the cone on ESI systems. If your compound has a phosphate group, it will just dirty up the system about the same as other samples you may run.
Not very much. Your MS will get a little dirty like it would with any other sample. The main issue with using phosphate buffers is that they are non-volatile and clog up the MS. The phosphate buffer will accumulate around the cone on ESI systems. If your compound has a phosphate group, it will just dirty up the system about the same as other samples you may run.
Thank you for enthusiastic reply, now, one more question arise in mind, which precautions should be taken in such type of analysis?
Ok sir, thanking you for kind suggestion
Again I will be in touch with; when I shall in between problems
The problem is not with the phosphate but the quantity. if you use phosphate buffer then it is not volatile. as large qty. of buffer passes in ESI or APCI which is difficult to remove and large amount of salt formation takes place in MS. Thats why all types of buffers are avoided if possible. if your drug is having the posphate group then it is not the issue. bcoz total conc. of drug is in nanogram. you can use TFA instead of buffers as it volatile and acidic(0.1%).
Like everyone mentioned above, no special precautions are needed. The amount of your compound is very tiny compared to any buffer you might run. Like Rajendra stated, there is a relatively large quanitiy of the phosphate buffer compared to your sample and that makes all the difference.
The main problem with phosphate buffers in MS in our experience is phosphate adducts. This will not be a problem with a phosphate group in the drug.
If you need to run buffers in the moderate range (ie no TFA) try ammonium formate or ammonium acetate. Using a volatile buffer system will not harm the source or the MS. I've heard that TFA is hard on an ESI source, but have no experience using it. I use primarily formic acid.
If you want to avoid interference of phosphate group on curtain plate use valco valve diverter to minimize the interferences even minimal amount of solute.
TFA tends to suppress ionization in ESI, so formate or acetate is preferred.
In addition to ALL previous Answers;
It is excellent Advantage you have to make use. Like Phospholipids, you can use Negative mode, mobile (Acetonitrile : water containing 2% NH4OH), you shall get very characteristic fragments, and M-PO4, M-H2O. If apply Positive mode, same basic mobile, you shall get characteristic m/z fragments of polar positive head.
You are lucky
hi,
If i want to analyse water soluble vitamin in LCMS analysis Lot of article told phosphate buffer only. But not able to do that. i tried to ammonium acetate, ammonium formate, 0.5% formic acid and from 2to8 PH. then tried lot of C18 and C8 column also. But B6 vitamine elute in AQUAS 100% itself. so not able to go for gradient. please advice me some idea. In vitamin B6 elute near the void volume. All buffer and All the column, All pH. Still now we are trying.
Rajendra Bhadane for Phosphate Buffer pH may be 7. But TFA around 2-
3. how can we use that. In case my molecule Vitamin B6 may i Use TFA. i tried that to but peak shape is very worst.
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