The weight-based crystal yield was

The weight-based crystal yield was calculated with respect to
the theoretical maximum extraction instead of to the total solute
weight. This deviation from earlier results (Abidin et al., 2009;
Sumaiya, Chuah, Koay, Salmiah, & Choong, 2010; Sumaiya et al.,
2007) is an issue of definition and does not dispute nor undermine
them. The GC separation spectrum for crude DHSA is shown
in Fig. 3(a). The major peak at a retention time (Rt) of 13.778 min
showed that the material was 69.55% pure, that is, a maximum
of 695.5 g of DHSA could be extracted from every 1000 g of crude
material. The yields at different final temperatures and IPA concentrations
are presented in Fig. 4(a). At 25 ◦C, 1000 g of crude material
yielded 499.0, 428.3 and 379.5 g of DHSA crystals for 70%, 80% and
90% IPA, respectively. The corresponding yields were 71.75, 61.58
and 54.57% as opposed to 49.90, 42.83 and 37.95%, respectively