Interactive spicpms data treatment using Nanocount

Transcription

1 V Cr Mn F Co Ni Cu Zn Nb Rh Pd Ag Cd Pt Au Hg Intractiv spicpms data tratmnt using Nanocount Grt Cornlis Univrsity of Gothnburg, Dpt. Chmistry and Molcular Biology Grt.Cornlis@chm.gu.s

2 spicp-ms: pros and cons Pros: Dtrmins polydisprs sizs particl numbr concntration dissolvd concntrations vs. particulats uss an xisting machin to calculat siz It can do small sizs fast TEM Extrmly snsitiv for vry low numbr concntrations Vry littl sampl prparation or sampl disturbanc Cons: Assum a sphrical shap Poor siz limits for crtain nanoparticls (.g. SiO 2 ) Works only for inorganic particls and only ss th inorganic part Only on lmnt at th tim (mayb TOF-spICPMS in th futur) Mthod optimization (dilution, dwll tim) Data tratmnt

3 Basic data intrprtation stps Export data from ICP-MS and import in your tool (.g. xcl) Obtain calibration curv Calculat histograms from raw data Dtrmin dissolvd/particulat lvl and rmov dissolvd data Calculat nbulisation fficincy Calculat diamtrs from signal intnsitis Calculat numbr concntrations from frquncis

4 Additional data intrprtation stps Drift corrction Signal discrimination Nbulisation fficincy dtrmination Particl siz distribution diting

5 Additional data intrprtation

6 Nbulisation fficincy Fit h so that calculatd siz = known siz Masur flow Calibrat Masur particl with known siz (NIST 60 nm) Assign a masurd intnsity to corrspond to th known siz (highst pak in histogram) Pac, H. E.; Rogrs, N. J.; Jarolimk, C.; Colman, V. A.; Gray, E. P.; Higgins, C. P.; Ranvill, J. F., Singl Particl Inductivly Coupld Plasma-Mass Spctromtry: A Prformanc Evaluation and Mthod Comparison in th Dtrmination of Nanoparticl Siz. Environmntal Scinc & Tchnology 2012, 46 (22),

7 Signal discrimination: Dconvolution If on has prfct knowldg how dissolvd signals look lik in histograms thy could b subtractd to provid a histogram fr of dissolvd signals Cornlis, G.; Hassllov, M., A signal dconvolution mthod to discriminat smallr nanoparticls in singl particl ICP-MS. Journal of Analytical Atomic Spctromtry 2014, 29 (1),

8 Calibration in th dconvolution mthod Diffrnt modls Basic Normal Polyagaussian Poissongaussian all paramtrs ar rlatd to th man Modl paramtrs ar fittd to svral dissolvd standards Fittd paramtrs provid prfct knowldg of th dissolvd signals

9 Dissolvd signal rmoval Svral mthods: Non Outlir analysis Dconvolution K-mans Choic of numbr of fitpoints - manual - Do a swp Cland up signal

10 PSD diting Us calculatd nbulisation fficincy to calculat diamtrs and numbr concntrations Edit PSD by Smoothing Rbinning Plot Log(masurd/ xpctd) vs. Log(masurd) concntration to stablish linar rang.

11 PSD calculation Us calculatd nbulisation fficincy to calculat diamtrs and numbr concntrations Edit PSD by Smoothing Rbinning Plot Log(masurd/ xpctd) vs. Log(masurd) concntration to stablish linar rang.

12 Why? spicp-ms is vry promising Probably th only tchniqu that can Monitor (inorganic) NMs in complx nvironmnts Masur ralistically low concntrations Quantify numbr concntrations Hardly disturbs th sampl ICP-MS is radily availabl in many labs Data tratmnt thory is availabl but will b dvlopd furthr and is impossibl to handl in a spradsht format

13 Thank you Contact:

14 Intrcpt = blank concntration Basic data intrprtation stps Export data from ICP-MS and import in your tool (.g. xcl) Calibration curv Slop = snsitivity

15 intnsity Basic data intrprtation stps Export data from ICP-MS and import in your tool (.g. xcl) Obtain calibration curv Calculat histograms from raw data Particl signal Particl signal histogram Tim (sc)

16 Basic data intrprtation stps Export data from ICP-MS and import in your tool (.g. xcl) Obtain calibration curv Calculat histograms from raw data Dtrmin dissolvd/particulat lvl and rmov dissolvd data.g. 60 nm Au NPs: Avrag dissolvd intnsity

17 Basic data intrprtation stps Export data from ICP-MS and import in your tool (.g. xcl) Obtain calibration curv Calculat histograms from raw data Dtrmin dissolvd/particulat lvl and rmov dissolvd data Calculat nbulisation fficincy Calculat diamtrs from signal intnsitis Calculat numbr concntrations from frquncis

18 Basic data intrprtation stps Particl signal histogram Particl siz distribution calculation N i = f(p i) η n q Dt d d = 3 (I I d I bkg )6ρqη M w πmt d 18