Sub-ppt detection of 1,2,3-Trichloropropane in water
with Ion Trap GC/MS/MS
ENVIRONMENTAL
Key Benefits
• The Agilent 240/7890 GC/MS/MS
system enables sub-ppt detection of
1,2,3-Trichloroporpane in drinking water satisfying
the California Public Health Goal level
• High sensitivity and reliable quantitation was
achieved by employing EI/MS/MS detection and
optimized Purge and Trap and GC conditions
• The selectivity, simplicity and affordability of an
Agilent 240 Ion Trap GC/MS makes it an excellent
tool for trace detection in environmental and other
samples
The well documented adverse health effects,
particularly its carcinogenicity, prompted the
monitoring of 1,2,3-trichloropropane (TCP) in
water in California. While there is no current
Maximum Contaminant Level (MCL) for TCP,
several regulatory agencies have released
guidelines:
California Department of Public Health
Notification level = 0.005 µg/L
Public Health Goal (PHG) = 0.0007 µg/L
Unregulated Contaminant Monitoring Rule (UCMR 3 administered by US EPA)
Proposed Minimum Reportable Level (MRL)= 0.03 µg/L
American Water Works Association (AWWA)
Recommended MRL = 0.005 µg/L; based upon 1/10 of Health Reference Level (HRL).
TCP is widely used as paint and varnish remover, as a cleaning and degreasing agent, and is
a byproduct of pesticide and other chemical manufacturing processes. Due to the common
occurrence and the high health risk associated with TCP, US wide TCP monitoring will start in
2013 as part of the proposed UCMR 3 list.
TCP is commonly measured by EPA methods 504.1, 551.1, 524.2, and 524.3, but these
methods allow a much higher MDL level than the 0.005 µg/L requested in California and
recommended by the AWWA. To achieve reliable detection at 5 ppt MRL level, the Agilent
7890/240 GC/MS system was used in EI/MS/MS mode. The concentration was carried out
by the Stratum Purge and Trap and Archon autosampler. 1,2-dibromo-3-chloropropane (DBCP)
was also included in the GC/MS/MS measurements.
0.005 µg/L
0.005 ppb 5 ng/L 5 ppt
The concentrations units are used interchangeably to express trace level concentrations.
Agilent GC/MS/MS Technology Advantage
BFB
Trace
Seg 3, All Other VOCs, Time: 1.95-17.00
Plot m/z 75
100 ppt of
1,2,3-Trichloropropane
10.00
10.25
10.50
10.75
11.00
11.25
minutes
Figure 1. TCP is traditionally measured in full
scan as outlined in EPA methods
524.2 and 524.3. Above is the
quant ion plot of m/z 75 for TCP at
100 ppt measured during a 524.3
analysis. The proposed new MRL
level is much lower at 5 ppt.
This information is subject to change without notice.
© Agilent Technologies, Inc. 2012
Published in USA, July 10, 2012
5990-9526EN
Figure 2. 1 ppt of TCP (product ion plot m/z 39) and 1 ppt DBCP (product ion plot m/z 45)
from EI/MS/MS measurement. 1 ppt represents the lowest calibration level and
was used for the MDL studies
9.2
9.4
minutes
9.6
9.8
10
10.2
10.4
1 ppt TCP
11.6 11.8
12
12.2 12.4 12.6 12.8
minutes
1 ppt DBCP
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Internal standard 1,2,3-tricholorpropane-d5 (TCP-d5) was used at 25 ppt concentration level
and calibration was performed for both TCP and DBCP in the range of 1 to 25 ppt.
The MDL-LOQ-LOD levels were statistically determined by 9-replicate injections of 1ppt level
water samples, using the 99% confidence level.
Rt
Average
Concentration MDL
LOQ
LOD
Analyte minutes
conc. ppt
%RSD
ppt
ppt
ppt
TCP
9.64
1.0299
2.5
0.0818
0.2604
0.0781
DBCP
12.29
1.0112
2.3
0.0738
0.2347
0.0704
MDL values of less than 0.1 ppt were
obtained for both analytes. MS/MS MDLs
are 300–500 fold lower than the ones
obtained by full scan 524 series methods
and seven times lower than the Public Health
Goal of 0.7 ppt.
A sensitive, precise and accurate method is
presented for the ultra low level detection of
1,2,3-trichloropropane and
1,2-dibromo-3-chloropropane in water. The
optimized concentrator and GC conditions
along with the selectivity of MS/MS allowed
sub-ppt detection levels for both TCP and
DBCP.
Figure 3. Calibration ranging from 1–25 ppt was performed for both analytes. The correlation
coefficient for TCP was 0.999 and for DBCP was 0.989. These values represent the
linearity of both the sample concentration process and the instrument response.
0
0.4
0.2
0.6
1.0
1.4
1.8
0.8
1.2
1.6
0
0.1
TCP - 5 Levels, 5 Levels Used, 5 Points, 5 Points Used, 0 QCs
y = 1.894695* x
R2 = 0.99941645
Type: Linear, Origin:Force, Weight:1/x2
TCP Calibration, 1–25 ppt
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Relative concentration
Relative responses
1
2