Comments on the papers recently published by Kalaivani et al.

Abstract

We argue that the so-called L-lysinium succinate 1 (D. Kalaivani et al, J. Cryst. Growth 426 (2015) 135-140), zinc chloride doped L-lysinium succinate 2 (D. Kalaivani et al, J. Cryst. Growth 428 (2015) 24-28), L-threonine phthalate 3 (J. Elberin Mary Theras, D. Kalaivani et al J. Cryst. Growth 427 (2015) 29-35) and sodium acetate doped L-tyrosine 4 (D. Arthi et al Spectrochim. Acta, 136A (2015) 168-174) are all dubious crystals. Taking compounds 1-4 as examples we show that EDAX is an inappropriate method for characterization of new materials based on elemental composition data.