About detectability and limits of detection in single particle inductively coupled plasma mass spectrometry

Abstract

Single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) offers unique features for the detection of particles, as well as for their quantification and size characterization. The detection capabilities of SP-ICP-MS are therefore not only limited to the concentration domains (of particles and dissolved related species), but also to the mass of element per particle and particle size domains. Discrimination and detection of particle events, based on the use of robust limits of decision (also known as critical values), and the estimation of the limits of detection in the different domains, require standardized metrological approaches that have not been clearly established yet. As a consequence, harmonized approaches and expressions to allow reliable comparisons between methods and instruments, as well as to process SP-ICP-MS data, are required. This paper is an attempt to summarize and review the different approaches applied up to now in relation to the detectability in SP-ICP-MS, and highlight the peculiarities of this topic in SP-ICP-MS. A holistic approach with criteria and expressions for the estimation of the different critical values and limits of detection in terms of the different instrumental and experimental parameters involved is proposed. Additionally, a calculation tool for estimating and predicting critical values and limits of detection under different experimental conditions is also included.

Application of Single-Particle ICP-MS to Determine the Mass Distribution and Number Concentrations of Environmental Nanoparticles and Colloids

“…Data analysis was performed via a custom Python script following the approaches of Pace et al and as described in detail in SI Data Analysis. Lower detection limits with increasing element mass were observed (Table S2), consistent with previous studies. , …”

“…Lower detection limits with increasing element mass were observed (Table S2), consistent with previous studies. 12,13 ■ RESULTS AND DISCUSSION Example 1: Aggregation of Microplastic Beads and Magnetite Nanoparticles. Aggregation of nanoparticles and colloids greatly affects their reactivity (surface area loss) and mobility (settling velocity).…”

Poisson process modelling of spike occurrence in single particle inductively coupled plasma mass spectrometry time scans for very dilute nanoparticle dispersions

“…The basic principle of sp-ICP-MS has been laid out in the 2000s [7] and some additional theoretical and methodological insights have been provided in the early 2010s, when the relevance of sp-ICP-MS as a standalone technique for characterizing nanoparticles was reasserted [3,4], paving the way for numerous experimental studies performed over the previous decade [8], even if several analytical and metrological challenges remain unsettled [9,10]. Theoretical works have been more scarce [11,12,13], except for the substantial modeling effort that has been devoted to data processing [14], and particularly on various ways to discriminate the signal produced by small nanoparticles from the background of the sp-ICP-MS signal [4,15,16,17,18].…”

Exploring the boundaries in the analysis of large particles by single particle inductively coupled plasma mass spectrometry: application to nanoclays

“…A 5-sigma criterion was selected for particle discrimination and estimation of size detection limits, as described in. 5 Size detection limits ranged from 270 to 300 nm with the cyclonic chamber, to 425 nm with the linear pass spray chamber setup. The combination of the relatively high intensity of the baseline signal due to polyatomic interferences, together with the fluctuations caused by the peristaltic pump when delivering flows at 13 μL min −1 , justified the higher size detection limits observed for the linear pass spray chamber system.…”

“…A 5 sigma (5σ) criterion was applied throughout the work for peak detection by SP-ICP-MS. The determination of the size and number concentration detection limits was based on the equations described by Laborda et al , 5 where the size LOD expression is equal to the critical value in size ( X size C ). A detailed description of these calculations can be found in Section S3 of the ESI †…”