English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

. Chemical ionization mass spectrometry (CIMS) techniques have becomeprominent methods for sampling trace gases of relatively low volatility.Such gases are often referred to as being “sticky”, i.e., havingmeasurement artifacts due to interactions between analyte molecules andinstrument walls, given their tendency to interact with wall surfaces viaabsorption or adsorption processes. These surface interactions can impactthe precision, accuracy, and detection limits of the measurements. Weintroduce a low-pressure ion–molecule reaction (IMR) region primarily builtfor performing iodide-adduct ionization, though other adduct ionizationschemes could be employed. The design goals were to improve upon previouslow-pressure IMR versions by reducing impacts of wall interactions at lowpressure while maintaining sufficient ion–molecule reaction times. Chambermeasurements demonstrate that the IMR delay times (i.e., magnitude of wallinteractions) for a range of organic molecules spanning 5 orders ofmagnitude in volatility are 3 to 10 times lower in the new IMR compared toprevious versions. Despite these improvements, wall interactions are stillpresent and need to be understood. To that end, we also introduce aconceptual framework for considering instrument wall interactions and ameasurement protocol to accurately capture the time dependence of analyteconcentrations. This protocol uses short-duration, high-frequencymeasurements of the total background (i.e., fast zeros) during ambientmeasurements as well as during calibration factor determinations. Thisframework and associated terminology applies to any instrument andionization technique that samples compounds susceptible to wallinteractions.

atmospheric measurement techniques

Performance of a new coaxial ion–molecule reaction region for low-pressure chemical ionization mass spectrometry with reduced instrument wall interactions