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The standard sample introduction system (SIS) of your inductively coupled plasma (ICP) determines many factors, including detection limits, precision, diferent matrix tolerances, and cost. ICP performance can often be improved [...]

Most students of corporation finance dream of a time when corporate administration will be held to a high degree of required responsibility- a responsibility conceived not merely in terms of stockholders' rights, but in terms of economic government satisfying the respective needs of investors, workers, customers, and the aggregated community. [ABSTRACT FROM AUTHOR]

With the recent introduction of the Iridia laser ablation system, Teledyne Photon Machines has made available the Long Pulse (LP) module for the Cobalt ablation chamber. Designed to be highly [...]

This column installment offers some suggestions for routine maintenance and offers guidance to troubleshoot common problems encountered in inductively coupled plasma-mass spectrometry (ICP-MS) sample introduction. Since inductively coupled plasma-mass spectrometry [...]

Nebulizer selection is a critical but often overlooked aspect of ICP-OES analyses. There are many different nebulizers available for ICP-OES, and choosing the optimal one can be confusing and difficult. [...]

Glass Expansion designed and patented the D-Torch, a revolutionary, demountable torch. The D-Torch uses high-precision engineering to provide the benefits of a demountable torch, such as lower running costs, chemical inertness, and configurable injector geometry, without compromising usability, performance, or durability. In this report, we discuss the effects of harsh matrices on torches, as well as the features, benefits, and improvements in analysis achieved with the D-Torch., Asingle-piece inductively coupled plasma (ICP) torch can be a costly consumable item requiring regular maintenance and replacement, particularly with aggressive sample matrices, such as hydrofluoric acid (HF), organic solvents, and [...]

Although Hg can be determined by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), with conventional pneumatic nebulization, the detection limits typically achieved are not adequate for most environmental applications. The cold vapor technique, using an acidified stannous chloride reductant (Sn[Cl.sub.2]) solution, is a widely-used technique to improve the sensitivity of Hg in atomic spectroscopy. The cold vapor process traditionally uses a dedicated instrument, or a cold vapor/hydride generation accessory connected to the ICP. However, for laboratories that routinely determine Hg and other elements in the same sample, switching between cold vapor and conventional nebulization modes adds complexity, increases argon (Ar) consumption, and reduces laboratory productivity. Glass Expansion's HydraMist[TM] spray chamber offers a sensitive, simple-to-use alternative that allows for simultaneous operation of conventional pneumatic nebulization and cold vapor/hydride generation. In this study, we evaluate the HydraMist's performance through the simultaneous detection of Hg using cold vapor and other trace elements by conventional pneumatic nebulization., Experimental Glass Expansion's HydraMistTM spray chamber offers a sensitive, simple-to-use alternative that allows for simultaneous operation of conventional pneumatic nebulization and cold vapor/hydride generation. In this study, we evaluate the [...]

Nebulizer selection is a critical but often overlooked aspect of ICP-OES analyses. There are many different nebulizers available for ICP-OES, and choosing the optimal one can be confusing and difficult. To achieve peak performance from your ICP, it is essential to choose the proper nebulizer based on your sample types, in addition to any necessary accessories to maintain long-term performance. In this study, we compare the performance of Glass Expansion's most popular concentric nebulizer designs for ICP-OES applications, as well as a parallel-path nebulizer from another vendor, providing a complete selection guide based on performance and design., Nebulizer selection is challenging because there are many different types available: concentric, parallel-path, and cross-flow, to name a few. By far, concentric nebulizers are the most common type found on [...]

A heated ([approximately equal to]90 [degrees]C) laminar flow interface has been designed to assist in the development of an argon electrospray sample introduction system for low-flow rate applications using inductively coupled plasma (ICP) spectrometry. Previously, the stability and robustness of the ICP were compromised by the entrainment of air, [N.sub.2], or gas mixtures (e.g., Ar-[N.sub.2]) from the electrospray source. Also, more concentrated organic solvents (e.g., 50% (v/v) methanol-water), typically introduced by electrospray, could generate carbon deposits that obstruct the entrance lens to an ICP optical emission spectrometer (ICP-OES) or the sampler/skimmer cone interface in an ICP mass spectrometer (ICP-MS), decreasing analyte sensitivity. With the new interface design, a stable spray of 5% (v/v) methanol-water in a pure argon environment is achieved, eliminating the aforementioned problems. The turbulence and the consequent droplet loss caused by high gas velocity around the electrospray capillary are mitigated by the use of a laminar-flow gas with the aid of a flow diffuser. The argon electrospray interface is successfully installed on an ICP-OES and an ICP-MS for the first time.

An automated sample introduction system, utilizing a demountable direct injection high-efficiency nebulizer (d-DIHEN), is successfully incorporated for the first time with an inductively coupled plasma optical emission spectrometer (ICP-OES) for the measurement of the phosphorus content in acid-digested nucleotides and deoxyribonucleic acid (DNA). With this experimental setup, the solution uptake rate and volume are reduced from 170 to 30 [micro]L [min.sup.-1] and from 10 to 2.4 mL, respectively, thereby reducing the required DNA sample mass for solutions containing 3 [micro]g [g.sup.-1] p from 300 to 72 [micro]g of DNA, in comparison to previous analyses in our laboratory using a glass concentric nebulizer with cyclonic spray chamber arrangement. The use of direct injection also improves P (I) 213.617 nm sensitivity by a factor of 4 on average. A high-performance (HP) methodology in combination with the previous sample introduction system and ICP-OES provides simultaneous, time-correlated internal standardization and drift correction resulting in relative expanded uncertainties (% U) for the P mass fractions in the range of 0.1-0.4 (95% confidence level) for most of the thymidine 5'-monophosphate (TMP), calf thymus DNA (CTDNA), and plasmid DNA (PLDNA) analyses. The d-DIHEN with HP-ICP-OES methodology allows for the quantification of DNA mass at P mass fractions as low as 0.5 [micro]g [g.sup.-1], further reducing the required DNA mass to 12 [micro]g, with small uncertainty ([less than or equal to] 0.4%). This successful approach will aid in the development and certification of nucleic acid certified reference materials (CRMs), particularly for these samples that are typically limited in volume.

This report highlights the superior performance of an inert Glass Expansion ICP sample introduction system compared to two alternative sample introduction systems. The Glass Expansion configuration consisted of the DuraMist [...]

Have you ever wondered when you should replace the RF coil on your ICP-OES or ICP-MS? The function of the RF coil is to transmit electromagnetic energy to the plasma, [...]

Dealing with a sample matrix high in total dissolved solids (TDS) is a common challenge for ICP spectrometry. Most 'real samples' contain considerable concentrations of TDS including soils, sludge, waste [...]

The temperature of a sample introduction system has a profound effect on ICP-OES and ICP-MS performance. Most ICP-MS instruments use a cooled spray chamber to reduce oxide and polyatomic interferences. [...]

Glass Expansion has partnered with Inorganic Ventures, the well-known certified reference material (CRM) manufacturer, to investigate a simple, low cost approach to improving ICP productivity. The benefits of Glass Expansion's [...]

It is standard operation to use dry argon as your ICP nebulizer gas in order to generate an aerosol and transport the sample to the plasma. However, when dealing with [...]

PURPOSE: Metastatic castration-resistant prostate cancer (mCRPC) with low androgen receptor (AR) and without neuroendocrine signaling, termed double-negative prostate cancer (DNPC), is increasingly prevalent in patients treated with AR signaling inhibitors and is in need of new biomarkers and therapeutic targets. METHODS: Candidate genes enriched in DNPC were determined using differential gene expression analysis of discovery and validation cohorts of mCRPC biopsies. Laboratory studies were carried out in human mCRPC organoid cultures, prostate cancer (PCa) cell lines, and mouse xenograft models. Epigenetic studies were carried out in a rapid autopsy cohort. RESULTS: Dickkopf-1 (DKK1) expression is increased in DNPC relative to prostate-specific antigen (PSA)–expressing mCRPC in the Stand Up to Cancer/Prostate Cancer Foundation discovery cohort (11.2 v 0.28 reads per kilobase per million mapped reads; q < 0.05; n = 117) and in the University of Washington/Fred Hutchinson Cancer Research Center cohort (9.2 v 0.99 fragments per kilobase of transcript per million mapped reads; P <.0001). DKK1 expression can be regulated by activated Wnt signaling in vitro and correlates with activating canonical Wnt signaling mutations and low PSA mRNA in mCRPC biopsies (P <.05). DKK1 hypomethylation was associated with increased DKK1 mRNA expression (Pearson r = −0.66; P <.0001) in a rapid autopsy cohort (n = 7). DKK1-high mCRPC biopsies are infiltrated with significantly higher numbers of quiescent natural killer (NK) cells (P <.005) and lower numbers of activated NK cells (P <.0005). Growth inhibition of the human PCa model PC3 by the anti-DKK1 monoclonal antibody DKN-01 depends on the presence of NK cells in a severe combined immunodeficient xenograft mouse model. CONCLUSION: These results support DKK1 as a contributor to the immunosuppressive tumor microenvironment of DNPC. These data have provided the rationale for a clinical trial targeting DKK1 in mCRPC (ClinicalTrials.gov identifier: NCT03837353). [ABSTRACT FROM AUTHOR]

The rate of major galaxy-galaxy merging is theoretically predicted to steadily increase with redshift during the peak epoch of massive galaxy development (1 ≤ z ≤ 3). We use close-pair statistics to objectively study the incidence of massive galaxies (stellar M1 > 2 × 1010M☉) hosting major companions (1 ≤ M1/M2 ≤ 4; i.e. <4:1) at six epochs spanning 0 < z < 3. We select companions from a nearly complete, mass-limited (≥5 × 109M☉) sample of 23 696 galaxies in the five Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey fields and the Sloan Digital Sky Survey. Using 5-50 kpc projected separation and close redshift proximity criteria, we find that the major companion fraction fmc(z) based on stellar mass-ratio (MR) selection increases from 6 per cent (z~0) to 16 per cent (z~0.8), then turns over at z~1 and decreases to 7 per cent (z ~ 3). Instead, if we use a major F160W flux-ratio (FR) selection, we find that fmc(z) increases steadily until z = 3 owing to increasing contamination from minor (MR > 4:1) companions at z > 1. We show that these evolutionary trends are statistically robust to changes in companion proximity. We find disagreements between published results are resolved when selection criteria are closely matched. If we compute merger rates using constant fraction-to-rate conversion factors (Cmerg,pair = 0.6 and Tobs,pair = 0.65 Gyr), we find that MR rates disagree with theoretical predictions at z > 1.5. Instead, if we use an evolving Tobs,pair(z) ∝ (1 + z)-2 from Snyder et al., our MR-based rates agree with theory at 0 < z < 3. Our analysis underscores the need for detailed calibration of Cmerg,pair and Tobs,pair as a function of redshift, mass, and companion selection criteria to better constrain the empirical major merger history. [ABSTRACT FROM AUTHOR]