RestekTrademarks:
Rtx.
TheGC is calibrated using standards that have been deriva- tized
by the same procedure as the samples. This process helps reduce
variability between extraction sets and laboratories. The low
point of the curve should be near the detection limit and the high
point should be 20 to 50 times higher. The last three standards
should have concentrations evenly distributed between the low
and high point in the curve.
Instrument stability is verified at every10 sample injections by
analyzing amid-point calibration standard.All calculated
compound concentrations in the standardmust have a recovery
of 70-130% of the theoretical value.
There are other quality controls thatmust be performedwhen
analyzing samples byUSEPAMethod552.2. They include
laboratory duplicates, field duplicates, laboratory blanks, field
blanks, laboratory fortifiedblank, laboratory fortified sample
matrix spikes, andquality control samples. Read through the
method and set-up a flowchart todeterminewhenquality control
samples shouldbe performed. Doing sowill reduce confusion
andmake the analysis straightforward.
Conclusion
The versatileRtx
®
-CLPesticide andRtx
®
-CLPesticide2 col-
min.1 2 3 4 5 6 7 8 9 10 11
min.1 2 3 4 5 6 7 8 9 10 11
CLP1
30m, 0.32mm ID (cat.#11139)
0.50µm
Figure1:
TheRtx
®
-CLPesticide andRtx
®
-CLPesticide2 columnsprovide thenecessary resolutionof haloacetic acids.
CLP2
30m, 0.32mm ID (cat.#11324)
0.25µm
c=solvent contaminant
1. monochloroacetic acid
2. monobromoacetic acid
3. dichloroacetic acid
4. dalapon
5. 1,2,3-trichloropropane
6. trichloroacetic acid
7. bromochloroacetic acid
8. dibromoacetic acid
9. bromodichloroacetic acid
10. chlorodibromoacetic acid
11. 2,3-dibromopropionic acid
12. tribromoacetic acid
Haloacetic acids, EPAMethod552.2onRtx-CLPesticides columns
Customhaloacetic acidmethyl derivatives std. [20-200µg/mL]mix inMTBE.
Oven temp.:
40°C (hold4minutes)@14°C/min. to200°C;
Inj. temp.:
200°C,
Table1:
LaboratoryPerformanceCheckSolution
Parameter
Measurement
Analyte
Concentration CLPResult
CLP2Result
AcceptanceCriteria
Instrument sensitivity
S/N
MCAA
0.006µg/mL
9
4
S/N>3
Chromatographic performance
PGF
BCAA
0.004µg/mL
0.92
1.05
PGF>0.08 and <1.15
1
2
3
4
c
5
6
7
8
9
10 11 12
1
2
3
4,
c
5
6
7
8
9
10 11 12
splitless, 2µL;
Carrier gas:
helium@46cm/sec.;
ECDDet.:
300°C
Product Listing
Rtx
®
-CLPesticides
(FusedSilica)
Stable to 340°C
Rtx
®
-CLPesticides2
(FusedSilica)
Stable to 340°C
ID
df (µm)
temp. limits
30-meter
ID
df (µm)
temp. limits
30-meter
0.32mm
0.50
-60 to 310/330°C
11139
0.32mm
0.25
-60 to 310/330°C
11324
umns exhibit proper resolutionofmany compounds including
haloacetic acids, chlorinated pesticides, chlorinatedphenoxy
herbicides, organophosphorus pesticides, and triazine herbicides.
These columns help analysts reduce instrument downtime and
increase sample throughput.
Formore information, call Restek at 800-356-1688 or
814-353-1300, ext. 4, or your localRestek representative.
For permission to repro-
duce any portion of this
application note, contact
Restek’s publications/
graphics department by
phone(ext.2128)orFAX.
Column performance
Resolution
CDBAA 0.010µg/mL
1.0
0.6
Resolution> 0.50
2,3-DBPA 0.010µg/mL
