Page 31 - Volume 5, Issue 2, July 2012

© Benaki Phytopathological Institute
Bempelou et al. 60
Results and discussion
In the present study the determination of
carbon disulfide and bromide ion was car-
ried out in plant products using gas chro-
matography with FPD and ECD detectors,
respectively. The two methods were found
to be effective for the extraction of the test-
ed compounds.
The retention time of the CS2 proved to
be very stable at 4.5 ± 0.2% min (Figure 1).
Confirmation can be obtained by GC/MS or
GC/ECD, but the clarification of the initial
compound used in the field is not possible.
The determination of inorganic bromide
was based on the use of the internal stan-
dard 3-bromo-1-propanol. The ratio of the
areas of 1-bromo-2-propanol and 2-bromo-
1-propanol (Figure 2) to the area of the inter-
nal standard was used for the calculation of
the regression curve of the derivatized stan-
dard solutions.
Validation results
The methods were evaluated by assess-
ing the basic validation parameters, namely
trueness, precision, sensitivity and linearity.
Trueness was estimated by the calculation
of the attained recovery, whereas precision
by assessing the relative standard devia-
tion (RSD) values. The linearity of the meth-
ods was assessed from the parameter of the
calibration lines. The limits of quantification
(LOQs) were also estimated.
Recoveries were calculated after the for-
tification of blank plant matrices from ap-
ples, leek, potato, strawberry, tomato and
wheat for dithiocarbamates and tomato, let-
tuce and rice for bromide ion. The obtained
values for CS2 ranged from 71% to 110% (Ta-
ble 1), while the corresponding values for in-
organic bromide were 80% to 99% (Table 2),
all in the required acceptable range of 70-
120% [5]. The relative standard deviation
values ranged from 4 to 15.5% for CS 2 and
Figure 1. Determination of carbon disulfide (CS2) in apples. Chromatograms of apple samples, matrix and fortified with
0.1mg/kg of CS2.