1-cyanoguanidine(BP - metformin tablets test)??

[badawalk]

Hello
is Retention Time correct?

BP Metformin tables test 1-cyanoguaindine
column : whatman partisphere 12.5cm x 4.6 mm 5um SCX
flow rate : 1ml/min
mobile phase : 17g/L Ammonium dihydrogen orthophosphate adjusted to pH 3.0 With orthophosphoric acid
column oven temp :25°c
dectection wavelength : 218nm
injet : 20ul

test rusult
1-cyanoguanidine RT : 1.5min
metformin Hcl RT : 59min

what do you think about metformin Hcl RT?

[qfiviera]

I´ve done it with a Luna SCX, and the rt for Metformin is about 13-16 minutes and 1-cyano is about 1.6 min. I think Metformin is taking too long to elute. How´s peak shape?

[Vlad Orlovsky]

Cyanoguanidine has no retention in RP or HILIC, you need to go to normal phase to get retention. Cyanoguanidine is not basic in nature like guanidine. It elutes in void in your method