Chemistry Reference
In-Depth Information
100
80
60
40
MetOH
THF
EtOH
i-PropOH
DMSO
20
0
0
20
40
60
80
100
Acetonitrile component (%)
Figure 23.3
Water-miscible solvents proposed to replace acetonitrile in chromatographic mobile phase
composition.
the benefits of replacing acetonitrile with methanol or longer chain alcohols [23, 24, 25]. Figure 23.3 shows
a plot which correlates the composition of several water-miscible solvents which could be used to replace the
acetonitrile as a component of the mobile phase as recommended according their eluotropic strength [26].
Sometimes, solvent replacement is not technically feasible and a reduced solvent consumption could be the
greenest solution. Reduced consumption patterns can be achieved following different strategies such as (1)
reduction of the pre-equilibration time and optimization of the analysis time after final peak elution, (2)
solvent recycling technologies and (3) reduction of the column's internal diameter (ID).
Replacing traditional LC methods by ultra performance liquid chromatography (UPLC) ones provided an
increased resolution in shorter run times which involves obtaining the same information faster than with LC.
UPLC reduces at the same time the volume of generated wastes and can be considered as a greener alternative.
In a press article of the February 2, 2010 [27], it was announced that Waters Corporation had installed
thousands of UPLC systems, replacing the workload of tens of thousands of traditional LC systems, supported
more than 500 peer-reviewed papers, demonstrated reduced solvent consumption by up to 95
for greener
laboratories, and had served the needs of regulatory agencies around the globe. One of the areas in which the
high resolution obtained by UPLC in extremely short analysis times is a really attractive characteristic is the
pharmaceutical development industry [28]. Novartis Pharmaceuticals Corporation highlights the benefits of
faster analyses by UPLC; which allow for a greater number of analyses to be performed in a shorter amount
of time, thus, increasing sample throughput and lab productivity. In addition, as test experiments are performed
more quickly, the overall method development time is decreased.
Supercritical Fluid Chromatography (SFC) considered as an alternative to normal phase HPLC, provides
the following advantages: (1) greener, typically only uses methanol as an organic modifier, (2) faster, (3)
useful for analysis of water labile analytes and (4) retain polar compounds. SFC uses CO
2
as supercritical
fluid which is non-toxic, non-flammable and can be recovered from waste streams. Johnsson and Johnsson
PRD, Janssen Pharmaceutica carried out a comparative study of the greenness of preparative supercritical
fluid chromatography (Prep-SFC) and preparative HPLC (Prep-HPLC) in the fine chemical and pharmaceutical
industry [29]. The comparison was made in terms of mass and energy requirements at different system
boundary levels, and their integral resource consumptions were evaluated on the example of a specific
%
