Mass spectrometry (MS) is widely regarded as the most sensitive and specific general purpose analytical technique. More than a century has passed for MS since the ground-breaking work of Nobel laureate Sir Joseph John Thomson in 1913. This Colloquium aims to (1) give an historical overview of the major instrumentation achievements that have driven mass spectrometry forward in the past century, including those leading up to the initial work of Thomson, (2) provide the nonspecialist with an introduction to MS, and (3) highlight some key applications of MS and explore the current and future trends. Because of the vastness of the subject area and quality of the manifold research efforts that have been undertaken over the last 100 years, which have contributed to the foundations and subsequent advances in mass spectrometry, it should be understood that not all of the key contributions may have been included in this Colloquium. Mass spectrometry has embraced a multitude of scientific disciplines and to recognize all of the achievements is an impossible task, such has been the diverse impact of this invaluable technique. Scientific progress is usually made via the cumulative effort of a large number of researchers; the achievements reported herein are only a representation of that effort.

Three fluorescent organic compounds—furocoumarin (FC), dansyl aniline (DA), and 7-hydroxycoumarin-3-carboxylic acid (CC)—are mixed to produce almost pure white light emission (WLE). This novel mixture is immobilised in silica aerogel and applied as a coating to a UV LED to demonstrate its applicability as a low-cost, organic coating for WLE via simultaneous emission. In ethanol solution and when immobilised in silica aerogel, the mixture exhibits a Commission Internationale d’Eclairage (CIE) chromaticity index of (0.27, 0.33). It was observed that a broadband and simultaneous emission involving coumarin carboxylic acid, furocoumarin and dansyl aniline played a vital role in obtaining a CIE index close to that of pure white light.

Furocoumarin (furo[3,2-c]coumarin) derivatives have been synthesized from single step, high yielding (82–92%) chemistry involving a 4-hydroxycoumarin 4 + 1 cycloaddition reaction. They are characterized by FTIR,¹H-NMR, and, for the first time, a comprehensive UV-Vis and fluorescence spectroscopy study has been carried out to determine if these compounds can serve as useful sensors. Based on the fluorescence data, the most promising furocoumarin derivative (2-(cyclohexylamino)-3-phenyl-4H-furo[3,2-c]chromen-4-one,FH), exhibits strong fluorescence (ФF = 0.48) with long fluorescence lifetime (5.6 ns) and large Stokes’ shift, suggestingFHcould be used as a novel fluorescent chemosensor. FH exhibits a highly selective, sensitive and instant turn-off fluorescence response to Fe³⁺over other metal ions which was attributed to a charge transfer mechanism. Selectivity was demonstrated against 13 other competing metal ions (Na⁺, K⁺, Mg²⁺, Ca²⁺, Mn²⁺, Fe²⁺, Al³⁺, Ni²⁺, Cu²⁺, Zn²⁺, Co²⁺, Pb²⁺and Ru³⁺) and aqueous compatibility was demonstrated in 10% MeOH-H₂O solution. TheFHsensor coordinates Fe³⁺in a 1:2 stoichiometry with a binding constant, K_a = 5.25 × 10³ M⁻¹. This novel sensor has a limit of detection of 1.93 µM, below that of the US environmental protection agency guidelines (5.37 µM), with a linear dynamic range of ~28 (~2–30 µM) and an R²value of 0.9975. As an exemplar application we demonstrate the potential of this sensor for the rapid measurement of Fe³⁺in mineral and tap water samples demonstrating the real-world application of FH as a “turn off” fluorescence sensor.

This paper describes, in detail, the development of a novel, low-cost and flexible drift tube (DT) along with an associated ion mobility spectrometer system. The DT is constructed from a flexible printed circuit board (PCB), with a bespoke ‘dog-leg’ track design, that can be rolled up for ease of assembly. The approach incorporates a shielding layer, as part of the flexible PCB design, and represents the minimum dimensional footprint conceivable for a DT. The low thermal mass of the polyimide substrate and overlapping electrodes, as afforded by the dog-leg design, allow for efficient heat management and high field linearity within the tube – achieved from a single PCB. This is further enhanced by a novel double-glazing configuration which provides a simple and effective means for gas management, minimizing thermal variation within the assembly. Herein, we provide a full experimental characterization of the flexible DT ion mobility spectrometer (Flex-DT-IMS) with corresponding electrodynamic (Simion 8.1) and fluid dynamic (SolidWorks) simulations. The Flex-DT-IMS is shown to have a resolution >80 and a detection limit of low nanograms for the analysis of common explosives (RDX, PETN, HMX and TNT).

Metaldehyde is extensively used worldwide as a contact and systemic molluscicide for controlling slugs and snails in a wide range of agricultural and horticultural crops. Contamination of surface waters due to run-off, coupled with its moderate solubility in water, has led to increased concentration of the pesticide in the environment. In this study, for the first time, rapid analysis (<~1 minute) of metaldehyde residues in water is demonstrated using paper spray mass spectrometry (PS-MS). The observed precursor molecular ions of metaldehyde were confirmed from tandem mass spectrometry (MS/MS) experiments by studying the fragmentation patterns produced via collision-induced dissociation. The signal intensity ratios of the most abundant MS/MS transitions for metaldehyde (177 → 149 for protonated ion) and atrazine (221 → 179) were found to be linear in the range 0.01 to 5 ng/mL. Metaldehyde residues were detectable in environmental water samples at low concentration (LOD < 0.1 ng/mL using reactive PS-MS), with a relative standard deviation 0.99, without any pre-concentration/separation steps. This result is of particular importance for environmental monitoring and water quality analysis providing a potential means of rapid screening to ensure safe drinking water.

Geosmin and 2-methylisoborneol (2-MIB) are amongst the most common earthy and musty taste and odour (T&O) compounds found in drinking water. With low odour threshold detection limits below 10 ng L⁻¹, and the complexity of raw water matrices, these two compounds provide a significant challenge for water companies globally. In this research, for the first time, a novel and fully automated micro-solid phase-extraction (μSPE) method coupled with gas chromatography (GC)–mass spectrometry (MS) has been developed for the detection of geosmin and 2-MIB for drinking water analysis. The new automated method described herein is environmentally friendly requiring low raw water sample volumes, of 25 mL, and only 50 μL of elution solvent. Our μSPE-GC–MS method exhibits excellent linearity for both compounds (R² > 0.999) and low limits of detection of 2.0 ng L⁻¹and 4.3 ng L⁻¹for geosmin and 2-MIB, respectively. The method showed excellent recovery rates (95.1–100.1%) and good precision (RSD < 7%) in raw sample matrices. Our approach is fully automated onto a robotic workstation which can be readily integrated into a laboratory workflow for routine water analysis. Furthermore, the method has excellent potential to be incorporated within a portable system for onsite analysis.