DeterminationofNa,Mg, P, K, Ca, Cr,Mn, Fe, Cu, Zn, Se, andMoby ICP-MS
8.
CleaningandMaintenance
a)
Themicromist nebulizermust be cleanedafter eachuse. Soak in5%nitric acidbathovernight or run
approximately2% (v/v) FlukaRBS-25 solution through it, using theperistalticpump, for approximately10
minutesand rinseby running laboratorywater through it for 10minutes.
b)
The spray chamber andTeflonend capmust be cleanedafter eachuse. Soakovernight in5%nitric acidor
25% (v/v) FlukaRBS-25 solution. RemoveO-rings fromend capbefore soakingand thoroughly rinse in
laboratorywater.
c)
The torchmust be cleanedafter everyuse. Soakovernight in5%nitricacidor 25% (v/v) FlukaRBS-25
solution.
d)
Change theperistalticpump tubingat least after everyweekof operationormoreoften, if needed.
e)
Clean the samplingand skimmer conesat least onceaweekorwhen therearedepositson theorifice. Soak
cones in5% (v/v) citranox solution for approximately1hr. Sonicate in citranox solution for approximately
15minutes and rinse thoroughlywith tapwater. Mixaluminapowderwithwater to forma slurryandusea
cotton swab toapply the slurryonto the cone for cleaning. Rinse thoroughly in tapwater and then sonicate
in laboratorywater. Again rinse thoroughly in laboratorywater, anddrywitha cleandust-free clothand
thenair dry, blowdrywithdust freeair, or place inaglasswareoven (40-50
C).
f)
ExtractionandOmega lenses shouldbe cleanedevery3- 6monthsdependingon the frequencyof use.
Polish the inner andouter surfacesof the lens to removediscolorationwithpolishingpaper (donot polish
the skimmer base).Dipa cotton swab intoanaluminapowder slurryand clean theorificeof each lens. Rinse
with laboratorywater and sonicate lenses for approximately5minutes in laboratorywater. Pourout
laboratorywater and repeat the sonicationprocedure for another 5minutes. Allow toair dryon clean
surfaceor place inaglasswareoven todry. Donotwipe. A slurry canalsobeprepared fromBarKeepers
Friend
Cleanser andPolish insteadof aluminapowder.
H.
ACCURACYANDPRECISION
1.
Theaccuracyof themethodwas assessedby comparing theNa,Mg, P, K, Ca, Cr,Mn, Fe, Cu, Zn, Se, andMo
concentrationsobtained for the LaboratoryControl, and ten representativeproducts (SPIFANmatrices) to those
obtainedbyother in-housevalidatedmethods. Inaddition, overspike recoveries andNISTSRMswereanalyzed
for accuracy.
2.
Theprecisionof themethodwas assessedbyperformingmultipleanalysesover several days.Overallmethod
standarddeviation for thismethod (includingwithin-dayandbetween-day sources) isestimated tobe5%or
better.
MTE-02
FORWORKINGGROUP/ERPUSEONLY
DONOTDISTRIBUTE
