3
Results
The analysis was carried out using a TraceGOLD TG-5MS column. The chromatogram of
1000 ng/mL of spiked phthalate ester in soft drink, in a full scan mode, is shown in Figure 1.
Phthalate esters are environmentally ubiquitous and this may therefore affect measured recoveries.
To minimize this problem, care was taken when preparing solutions for calibration and extractions.
Longer chain phthalate esters such as DNP, DNOP, and DHXP can absorb to the glassware and the
lower extraction recoveries were expected.
The results for the calibration data and for the phthalate esters extracted from a soft drink are
displayed in Table 2. The coefficients of determination (R
2
) between the area ratio of sample and
internal standard for all phthalate esters were > 0.99 (Table 2), demonstrating excellent method
linearity using the TraceGOLD TG-5MS GC column.
MS Conditions
Instrumentation:
Thermo Scientific™ ISQ™ GC single quadrupole mass spectrometer
Transfer line temperature:
300 °C
Source temperature:
260 °C
Ionization conditions:
EI
Electron energy:
70 eV
SIM scan parameters:
Table 1
Compound
Abbrev Scan start
time (min)
Quan ion
(Qual Ion)
Dwell
time (s)
Dimethylphthalate
DMP
7.0
163 (194, 77)
0.08
Diethylphthalate
DEP
10.50
149 (177, 121)
0.08
Benzyl benzoate
(Internal standard)
ISTD
12.50
105 (212, 91)
0.08
Diisobutyl ester phthalic acid
DIBP
14.00
149 (223, 205)
0.08
Di-n-butyl phthalate
DBP
15.00
149 (223, 205)
0.08
Bis(2-methoxyethyl)
phthalate
DMEP
15.75
59 (149,193)
0.08
Bis(4-methyl-2-pentyl)
phthalate
BMPP
16.30
149 (251,167)
0.08
Bis(2-ethoxyethyl) phthalate
DEEP
16.80
45 72,149
0.08
Dipentylphthalate
DPP
17.20
149 (237, 219)
0.08
Di-n-hexyl phthalate
DHXP
18.20
104 (149, 76)
0.04
Benzyl butyl phthalate
BBP
18.20
149 (91, 206)
0.04
Bis(2-n-butoxyethyl)
phthalate
DBEP
19.50
149 (223, 205)
0.08
Dicyclohexylester Phthalic
acid
DCHP
20.30
149 (167, 83)
0.08
Dioctyl Bis(2-ethylhexyl)
phthalate
DEHP
20.30
149 (167, 279)
0.08
Di-n-octyl phthalate
DNOP
21.40
149 (279, 167)
0.08
Di-nonyl Phthalate
DNP
22.80
149 (293, 71)
0.08
Table 1: SIM Scan parameters
Injection Conditions
Instrumentation:
TriPlus Autosampler
Injection volume:
1 µL
Pre- and post-injection dwell time:
3 s
Data Processing
Software:
Thermo Scientific™ Xcalibur™ software
