Electronic cigarettes containing nicotine salts are gaining in more and more popularity worldwide. However, information about this kind of products is very limited. We developed a high performance liquid chromatography method for simultaneously determination of seven organic acids & nicotine. To get deep insights into this new and hugely popular type of products, organic acids, nicotine content, nicotine source and pH from 34 e-liquids of prefilled cartridges for nine brands were analyzed. The results showed that: (1) Benzoic acid nicotine salt was detected in about one third samples, nicotine ditartrate was detected in one sample, but the kind of nicotine salts could not be qualified in other samples, indicating that more effective target or non-target methods should be developed for qualitative and quantitative analysis of nicotine salts in e-liquids. (2) Nicotine content of e-liquids containing nicotine salts was significantly higher than that of ordinary e-liquids (not labelled containing nicotine salts) reported in literature report. The claimed concentrations of nicotine labeled on electronic cigarettes containing nicotine salts were often higher than measured values, and the nicotine contents of some samples were not labeled at all. (3) Enantiomeric composition of nicotine showed that relative amount of R-(+)-nicotine was not higher than 2.72%, showing that nicotine in the e-liquids originated from tobacco, rather than from artificial synthesis. (4) The pH of e-liquids containing nicotine salts was significantly lower than that of ordinary e-liquids.