This review covers developments in the design of Laser Ablation (LA) cells, the associated transport tubing assembly, and their coupling to Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) instrumentation. Recent ablation cell designs have reduced the pulse response duration for a single laser shot to <10 ms, using the criterion of the full peak width at 1% of the height of the maximum signal intensity. The evolution towards these low dispersion systems has been profoundly influenced by our understanding of processes driving the initial dispersion, of the design aspects of the cell and tubing that influence transport-induced dispersion and transport efficiency, and of limitations imposed by the temporal resolution of ICP-MS instruments, all of which are discussed. Rapid response LA-ICP-MS systems greatly benefit throughput and sensitivity, which are key parameters in 2D and 3D imaging at high lateral resolution. The analysis and imaging of biological material has come to the forefront as a key application of LA-ICP-MS. The impact of the technical developments in LA-ICP-MS systems on emerging applications, including multiplexed metal-tagged antibody detection (for immunohistochemistry), nanoparticle and compound hypo- and hyperaccumulation, and (intra-) cellular/histological studies, is also discussed

In recent years, laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) has gained increasing importance for biological analysis, where ultratrace imaging at micrometer resolution is required. However, while undoubtedly a valuable research tool, the washout times and sensitivity of current technology have restricted its routine and clinical application. Long periods between sampling points are required to maintain adequate spatial resolution. Additionally, temporal signal dispersion reduces the signal-to-noise ratio, which is a particular concern when analyzing discrete samples, such as individual particles or cells. This paper describes a novel, two-volume laser ablation cell and integrated ICP torch designed to minimize aerosol dispersion for fast, efficient sample transport. The holistic design utilizes a short, continuous diameter fused silica conduit, which extends from the point of ablation, through the ICP torch, and into the base of the plasma. This arrangement removes the requirement for a dispersive component for argon addition, and helps to keep the sample on axis with the ICP cone orifice. Hence, deposition of sample on the cones is theoretically reduced with a resulting improvement in the absolute sensitivity (counts per unit mole). The system described here achieved washouts of 1.5, 3.2, and 4.9 ms for NIST 612 glass, at full width half, 10%, and 1% maximum, respectively, with an 8–14-fold improvement in absolute sensitivity, compared to a single volume ablation cell. To illustrate the benefits of this performance, the system was applied to a contemporary bioanalytical challenge, specifically the analysis of individual biological cells, demonstrating similar improvements in performance.

No abstract

Cellular therapy is emerging as a promising alternative to conventional immunosuppression in the fields of hematopoietic stem cell (HSC) transplantation, autoimmune disease, and solid organ transplantation. Determining the persistence of cell-based therapies in vivo is crucial to understanding their regulatory function and requires the combination of an extremely sensitive detection technique and a stable, long-lifetime cell labeling agent. This paper reports the first application of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to perform single cell detection of T cell populations relevant to cellular immunotherapy. Purified human CD4 + T cells were labeled with commercially available Gd-based magnetic resonance imaging (MRI) contrast agents, Omniscan and Dotarem, which enabled passive loading of up to 10 8 Gd atoms per cell. In mixed preparations of labeled and unlabeled cells, LA-ICP-MS was capable of enumerating labeled cells at close to the predicted ratio. More importantly, LA-ICP-MS single cell analysis demonstrated that the cells retained a sufficient label to remain detectable for up to 10 days post-labeling both in vitro and in vivo in an immunodeficient mouse model.

A prototype time-of-flight mass spectrometer and prototype laser ablation chamber have been used together for the first time, providing differentiation between three forms of harmful asbestos fibre in biological samples.