title: Spatial inhomogeneity of metals in particulate matter on ambient air filters determined by LA-ICP-MS and comparison with acid digestion ICP-MS.
abstract: Laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) has been used to examine the spatial distribution of metals in particulate matter on ambient air filters. The implications of the inhomogeneous distribution observed for the sub-sampling of such filters for multiple analyses have been discussed. It has been shown that large biases in measured values may occur unless the position and size of the sub-sample are chosen judiciously. Additionally, LA-ICP-MS has been compared against acid digestion ICP-MS as an alternative method for the determination of metals in particulate matter. It has been shown that the majority of variation in the LA-ICP-MS sensitivity accrues from small differences in the positioning of samples.
authors.affiliation: Analytical Science Team, National Physical Laboratory, Teddington, Middlesex, UKTW11 0LW. richard.brown@npl.co.uk
authors.forename: Richard J C
authors.initials: RJ
authors.lastname: Brown
authors.forename: Kym E
authors.initials: KE
authors.lastname: Jarvis
authors.forename: Benoit A
authors.initials: BA
authors.lastname: Disch
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Goddard
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Brown
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods; D005374:Filtration; D007834:Lasers; D013058:Mass Spectrometry / Q000379:methods*; D008670:Metals / Q000032:analysis*; D052638:Particulate Matter / Q000032:analysis*; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: D000393:Air Pollutants; D008670:Metals; D052638:Particulate Matter