- I need to analyze piperazine in an ultrapure water, but with 0.085 mol/L NaHCO3 & 0.040 mol/L NaCl matrix with pH set to 7 and to 3.

- I have a HPLC–ELSD available, and can work according to http://www.tandfonline.com/loi/ljlc20; 10.1081/JLC-120025426 , but as I have found, the NaHCO3 & NaCl also perform a signal on ELSD, and exactly there, where the piperazine (I have tried it with a C18 column so far).

- I can use mobile phases with water (acidic, with HNO3 or slightly basic [pH 7,6–7,8] with (NH4)HCO3 and acetonitrile with various compositions or gradients. But with the C18 column I am still not able to separate the salts.

- Can some HILIC column (e.g. Alltech Alltima Cyano (250 x 4.6 mm)) separate also the NaHCO3 & NaCl salts from the piperazine?

- So far no other detector is available to me.