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Introduction: Many patients with non-muscle invasive bladder cancer (NMIBC) will develop recurrences of their tumour after their first resection. Flexible cystoscopy under local anaesthesia with Holmium-YAG laser ablation of tumour (FHoLAT) is safe, well tolerated procedure with significant cost savings when compared to cystoscopy under general or regional anaesthesia. We retrospectively analysed the outcomes of a large series of patients undergoing FHoLAT at our institution between April 2006 and September 2013. Patients and methods: Patients were offered FHoLAT if the tumour recurrence was small and/or they were deemed unfit for regional or general anaesthesia. Patient data was extracted from medical records. The primary outcomes were overall survival (OS), cancer-specific survival (CSS), progression-free survival (PFS) and recurrence-free survival (RFS). Results: 232 patients with a total 522 FHoLAT procedures were included. The median follow-up was 74.8 (43.5–101) months; 18% were discharged after a recurrence free follow-up duration; 52.2% had one FHoLAT, 19.8% had two FHoLATs, 11.2% had three FHoLATs and 16.8% had four or more FHoLAT. At initial diagnosis 24.1% of patients had G1pTa, 47% G2pTa, 9.9% G3pTa and T1 in 18.9%. 4.3% had concurrent carcinoma in situ. At 10 years, OS was 47.4%, CSS was 94.1%, PFS was 82.1%, RFS was 15.8%. Conclusions: FHoLAT for bladder tumour recurrences has an acceptable CSS and PFS for patients with small low-grade tumours or patients with high-grade or T1 tumours who are unfit for regional or general anaesthesia. The role of FHoLAT in unfit patients seems clear, but further prospective trials are needed to define its role in other patient groups, particularly high-grade NMIBC. Level of evidence: 3b-4

The successful determination of uranium, lanthanum, cerium, neodymium and yttrium by LA–ICP-AES is reported. LA was performed using a Q-switched Nd:YAG laser operating at 1064, 532 or 355 nm. Ablation at 355 nm was shown to offer optimum performance. The sample matrix consisted of a mixture of lithium and potassium chlorides which, when molten, form the electrolyte for an electro-refining process for the treatment of spent nuclear fuels. Analytical recoveries in the range 96–103% were obtained with a relative standard deviation of 1–3%, i.e., U = 100%, La = 100%, Ce = 96%, Nd = 97% and Y = 103%. The detection limit for uranium was 25 µg g–1 using the optimum LA conditions. The use of solid standards closely matching the sample material was found to be essential if accurate analyses were to be obtained. Calibration using uranium compounds other than the specific compound found in the sample was unsuccessful. For results of the highest quality, single phase materials were produced to allow for accurate internal standardization. Spectral interferences were minimized by the use of high resolution spectrometry. The reliability of the analyses was improved by the introduction of additional aerosol processing in the form of a Scott-type spray chamber between the ablation cell and the ICP torch.

Investigations into the use of hydrogen addition in the nebulizer gas of an argon inductively coupled plasma (ICP) in an ICP-mass spectrometer for the possible reduction of polyatomic interferences are reported. Hydrogen was found to worsen interferences such as ArO + and ArCl + with respect to an all-argon system. In contrast to these argon-based interferences the levels of MO + were found to be reduced by approximately a factor of 10 with the addition of hydrogen. The hydrogen-argon system was optimized using a simplex procedure. At the defined, optimum the level of CeO + compared to that of Ce + was approximately 0.5%. Detection limits for Gd in 10 μg cm −3 La were 15.9 ng cm −3 in the hydrogen-argon system compared to 2000 ng cm −3 in the all-argon system. These conditions were also used for the analysis of the CRM Bastnasite mill feed ore. IGS 40, using slurry nebulization. The determination of Sm was made possible and the determination of Gd slightly improved by the hydrogen addition. It was concluded that hydrogen addition in an appropriately optimized system offers improvements in heavy rare earth element (REE) determination, in the presence of their lighter counterparts, provided the concentration of the light REE does not exceed μg cm −3 levels.

Slurry nebulization inductively coupled plasma atomic emission spectrometry (ICP-AES) has been investigated to examine how the particle size distribution of the slurry affects analytical accuracy and precision. An empirical upper diameter for the particle size distribution of a slurry of 2–2.5 μm was derived from the analysis of a range of slurries possessing different particle size distributions. A model for slurry particle transport is suggested that gives good agreement with experimental data. The model assumes that for an arbitrarily defined but realistic standard slurry, the maximum allowable particle size is that which allows the occupation of every aerosol droplet by one solid particle. Theoretical considerations and empirical data suggest that for accurate analyses by slurry nebulization, the particle size distribution of the slurry should not exceed a value, determined by density, of 2.9 μm for a material of density 1 g cm−3 falling to 1.5 μm for a material of density 7 g cm−3. Certain carbonaceous materials were shown to be susceptible to micro-flocculation, resulting in 5–10 member assemblies formed from fine primary particles. This led to transport behaviour and analytical recoveries that would normally be associated with slurries of much coarser particle size. With the required conditions of complete dispersion and the correct particle size distribution, slurry nebulization ICP-AES was applied successfully to a range of certified reference materials using simple aqueous standards for calibration.

Hexafluoroethane (Freon 116), added to the argon nebulizer gas, has been investigated as a potential volatilization aid for refractory materials in slurry nebulization inductively coupled plasma atomic emission spectrometry (ICP-AES). The introduction of Freon 116 resulted in apparently unusual plasma spectrochemistry, which yielded non-linear calibration curves. These were attributed to classical mass action buffering involving highly stable metal fluoride species. This dictated against the use of Freon 116 as a volatilization aid in slurry nebulization ICP-AES.

This paper reports a theoretical study of the feasibility of using laser-excited ionic fluorescence in time correlation with ion counting, termed coincidence laser spectroscopy (CLS), for improved specificity in the detection of ions in ICP-MS. The technique is here named ICP-MS-CLS. A number of factors are considered including: the preferred instrumental configuration, simulation of the performance of the optical detector and correlation step in reducing background, the spectroscopy of the selected of isotopes, 10Be+, 55Fe+, 63Ni+, 90Sr+, 99Tc+, 147Pm+, 238U+, 238Pu+ and 241Am+, which might be appropriate candidates for ICP-MS-CLS detection, the laser power required to attain saturation, the effects of ion energy and energy spread on pumping efficiency, the optical abundance sensitivity for adjacent isotopes of the same element, and the detection limits obtainable under a variety of scenarios. The ICP is established as an ideal ion source for elemental mass spectrometry, but as shown here, the ion energy spread produced is too large for optimum optical pumping because the ions are Doppler shifted to an extent that not all of them would be excited efficiently by a narrow-line laser source. This necessitates the inclusion of an ion cooler into the instrumental configuration so that ions maybe brought into resonance with the laser with 100% efficiency. The calculations show that for ions with simple spectra, such as 90Sr+ which can be repetitively pumped by the laser to produce a photon burst, ICP-MS-CLS can reduce the effect of very high backgrounds, 106 cps on mass and 1010 cps at adjacent mass, to low levels and improve detection limits by 2–3 orders of magnitude compared with the normal technique. Optical abundances of 10−5–10−9 are achievable which, combined with the mass abundance sensitivity of 10−5, yields overall abundance sensitivities of 10−10–10−14. This is of the same order as techniques such as accelerator mass spectrometry (AMS) or resonance ionisation mass spectrometry (RIMS). The technique is much less efficient for ions that undergo optical trapping and emit only one photon when pumped and/or exhibit hyperfine structure which distributes the oscillator strength over several hyperfine components. These factors significantly degrade performance and indicate a requirement for further refinement in terms of using two-colour excitation, or quenching of meta-stable levels, to enable the recycling of ions for further pumping.

The use of inductively coupled plasma atomic emission spectrometry (ICP-AES) for the determination of 235U: 238U isotope ratios in U–Zr metal alloys (90% m/m U, 10% m/m Zr) is described. Conventional pneumatic nebulization and laser ablation sample introduction techniques were utilized. The results of the determination agreed, within experimental uncertainty, with isotope ratios determined by thermal ionization mass spectrometry (TIMS), e.g., 235U: 238U for conventional nebulization = 2.091 ± 0.006, for laser ablation = 2.092 ± 0.015 and for TIMS = 2.0940 ± 0.0004. The precision, i.e., the relative standard deviation (RSD), of the sequential determination of the intensities of the 235U and 238U components of the U emission line and the resultant isotope ratios was improved significantly by the use of an intrinsic internal standard (Zr), i.e., RSD = 1.6% to RSD = 0.17%.

The use of continous flow vapour generation to improve the determination of thallium by atomic spectrometry has been investigated. Attempts to generate volatile organothallium compounds were unsucessful but using sodium tetrahydroborate a volatile thallium species was produced. Evidence was obtained to suggest that the vapour phase species was thallium(I) hydride, TlH. At room temperature noisy signals were obtained, but when the reaction manifold was chilled to 0 °C the signals were far more stable. Cooling did not significantly change the sensitivity. A characteristic concentration of 4 ng cm–3 was obtained for continous flow vapour generation determination of thallium by atomic absorption spectrometry (AAS). This is a 1500-fold improvement on the previous sensitivity for batch vapour generation AAS. Continous vapour generation also appears to eliminate any serious interferences from other hydride-forming elements. Flow injection of nitric acid between samples was used to remove memory effects.

A new method for the determination of lead by vapour generation atomic spectrometry is described. This is based upon continuous flow methodology and involves the derivatization of lead, in the presence of an oxidant, with sodium tetraethylborate to yield volatile tetraethyllead. Simplex optimization was applied to this system and to conventional hydride generation. Characteristic concentrations of 0.36 ng cm–3(Pb 283 nm) and 0.145 ng cm–3(Pb 217 nm) for alkyl generation atomic absorption spectrometry were observed. These are approximately 4–5 times better than the equivalent hydride system and superior to all reliable literature values for characteristic concentrations of lead hydride generation atomic absorption spectrometry. Using the 283 nm lead line, limits of detection (3s) obtained for the hydride and alkyl generation systems were 0.62 and 0.07 ng cm–3, respectively. The determination of lead in a standard reference water (NIST SRM 1643c) is reported and good agreement obtained between the certificate value (35.3 ± 0.9 ng cm–3) and the experimentally derived value (34.8 ± 1.4 ng cm–3).

The vapour generation of cadmium by reaction in aqueous solution with sodium tetraethylborate was performed using a conventional continuous flow reactor. This vapour generation system was successfully interfaced with atomic absorption and fluorescence instrumentation. A detection limit, with fluorescence detection, of 20 ng dm–3(3σn–1) was obtained after optimization of the chemistry using simplex routines. Interferences from transition metal ions (e.g., NiII, CuII) were observed but were attenuated by the use of citrate as a masking agent. Vapour generation atomic fluorescence spectrometry was successfully applied to the determination of cadmium in potable waters, a National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 1643c Trace Elements in H2O, and Community Bureau of Reference (BCR) Certified Reference Materials (CRMs) 144 Sewage Sludge–domestic and 145 Sewage Sludge–industrial. Full recovery of cadmium spikes was obtained from UK drinking waters. A value of 12.6 ± 0.5 ng cm–3 of cadmium was obtained for NIST SRM 1643c (certificate value = 12.2 ± 0.1 ng cm–3 of cadmium) whilst the cadmium content of BCR 144 and 145 (certificate value 3.41 ± 0.25 and 18.0 ± 1.2 µg g–1, respectively) was estimated at 3.34 ± 0.15 µg g–1(BCR 144) and 18.24 ± 0.7 µg g–1(BCR 145).

The use of molecular gas addition as a volatilization aid in slurry nebulization inductively coupled plasma atomic emission spectrometry (ICP-AES) has been investigated using a combination of rigorous optimization strategies and spectrochemical measurements. The addition of hydrogen resulted in an improvement in accuracy, which corresponded to the elimination of atomization interferences observed during the analysis of a highly refractory material by slurry nebulization ICP-AES. This ability to decompose refractory particles correlated with higher rotational plasma temperatures. This increase in temperature from 2200 to 3900 K was attributed to increased energy transfer from the toroidal to the annular region of the ICP as a consequence of the higher thermal conductivity of hydrogen compared with argon. This process appears to be self-limiting and a mechanism is proposed to account for this behaviour.