ADV06-15_1-412

397 / 413

Environmental
dissociation (CID) is used to generate the frag­
ment ions. CID spectra for paraquat and diquat
Table 1 MRM tra nsitions and MS cond it ions used to generate
C10 spectr a for paraquat and diquat.
are shown in Figures 2 and 3. This approach has
Precursor Ion FragmentIons DP CollisionEnergy
been used in many pharmaceutical and environmlz
l!!lill leV)
Paraquat [Ml+- W] 170a 40 30 mental applications, to generate unmatched limits
18S 169b of detection or quantification, precision, and accu­
Paraquat-d8 [M " - D' ] 178a 40 30 racy. For accurate quantification, we used
193 (int. std.) par aqu at-dS and diquat-d4 as internal standards
Diquat [ M - W] 157a 35 30
" (Table 1), to compensate for matrix effects and to
183 168b
Diquat·d4 [M " - D' ] 158a 35 30
~(int. std .)
Figure 2 CIOspect ra for paraquat" at CE == 25eV.
a - MRM transition 185/ 170 used for quantification
b - MRM transition185/169 used for confirmation
[M"-H']
, ', n:
b
I~
corr ect for random and systematic errors in sepa­
ration and detection.
For trip licate injections of 8 concentrations of ana­
lytes in deioni zed water and in lake water, from
5f-lg/lOOmL to 100f-lg/100mL for paraquat and
from lg/lOOmL to 100f-lg/lOOmL for diquat,
correlation coefficients for calibration curves were
>0.995, using a linear fit and 1/x weighting factor.
These results indicat e that quantification can be
perfo rmed with good linearity and sensitivity.
Minimum detection limits (MDL) for the method,
for paraquat and diquat in deionized water, were
5f-lg/L and 0.1ug/L, respectively.
LC/MS is a powerful tool for analyses of challenging
environmental contaminants. In LC/MS analyses of
paraquat and diq uat, the combination of an
Applied Biosystems API 3200™mass spectrometer
and an Ultra Quat HPLC column ensures fast, sen­
sitive, and accurate results.
Figure 3 CIOspect ra for diquat' at CE == 25eV.
a - MRM transition 183/ 157 used for quantification
b - MRM transition183/ 168 used for confirmation
[M"-H']
a
1'-b
II I ., , ••~. s » " . ...., ,, " " ."" . " , " ).'"' . .., . " .... "n'
free literature
Simple, SensitiveHPLC/UV Analysis for Paraquat and DiquatUsing High-Recovery Solid Phase
Extractionand anUltra Quat HPLC Column
These highly charged quaternary amines are poorly retained onalkyl stationary phases. Using only
acetonitrile,water, and a solvation-blockingreagent, our separationsystemalters theinteractions
among analyte, mobile phase, and stationary phase, and promotessolubility of theanalytesin the
stationary phase. In oursystem, the detection limit is 6ppb for either herbicide, andtheanalysis is
completed in less than 10 minutes. An optimized solid phase extractioncartridge concentratesthe
herbicides for theanalysis. lit. cat.# 580006
Environmental HPLC: Applications-Columns-ReferenceMaterials
Restek HPLCcolumnssupportenvironmental HPLCapplicationswith rapid analysis times and effec­
tive analyte resolution. Sample turn-around canbe50%faster, or more, thanwith alternative columns.
Inaddition, weprepare analytical reference materialsand sample clean-up products for thesemeth­
ods. Applications in thispublication include polyaromatic hydrocarbons, carbamates, phenoxyacid her­
bicides,explosives, carbonyls, and paraquatldiquat. lit. cat.# 5974lA
2006.03 • 15 •
Reference
L Simple, SensitiveHPLCIUVAnalysis for ParaquatandDiquat, Using
High-Recovery Solid Phase Extraction andanUltra QuatHPLCColumn
Applications Note580006, RestekCorporation, Feb. 2006.
Reference availablefrom Restekon request.
Ultra Quat Columns & Guard Cartridges
Spm Column, 4.6mm cat. # price
~50mm 9181565 $399
150mm(withTrident'" Inlet Fitting) 9181565-700 $414
UltraQuat Guard cartridge".s'--:::c::-::-:=:-::--:::c:-::_
10 x 2.1mm 918150212 $131
10 x4.Omm 918150210 $131
20x 2.1mm 918150222 $131
20x 4.Omm 918150220 $131
Paraquat & Diquat Calibration Mix
diquat dibromide paraquat dichloride
1,000/-lg/mL each inwater, l mt/ arnpul
cat. # 32437 (ea.) $26
free literature
HPLC Essentials
GenuineRestekReplacement Parts will keep your Agilent,
Beckman,Hitachi, PerkinElmer, Shimadzu, ThermoSeparation
Products,orWaters systemrunning smoothly and chromatogra­
phy sharp. Restek parts equal or exceed theperformanceof
original components. lit. cat.# 59012A
800-356- 1688 ·
Website : E-mail : TelNo : 03 9762 2034 . . . in AUSTRALIA