Analytical techniques quantify trace impurities in high-purity metals and reagents.
the verdict
SUPPORTED
the evidence backs this
refutedsupported
the weight of evidence
9 sources for · 0 against
Peer-reviewed literature demonstrates that diverse analytical techniques, such as ICP-MS, GC-MS/MS, XRF, and LC-MS/MS, are routinely employed and validated to quantify trace impurities in high-purity metals and chemical reagents.
Monoelemental calibration solutions are the most common reference in elemental analysis, linking measurement results to the International System of Units (SI). National Metrology Institutes (NMI) prepare these solutions as certified reference materials (CRM) and determine their elemental mass fraction with high accuracy. Characterization with high accuracy is one of the most critical steps in CRM production. This report compares the approaches taken by the NMIs of Türkiye (TÜBİTAK-UME) and Colombia (INM(CO)) in preparing and characterizing cadmium calibration solutions with a nominal value of 1 g kg−1. Each NMI produced CRMs using an independent batch of cadmium calibration solution and assigned mass fraction values to both their own solutions and those of the other NMIs. TÜBİTAK-UME employed a primary difference method (PDM) to assess the purity of a cadmium metal standard, quantifying all possible impurities using a combination of instrumental analytical techniques. The defined purity standard was used for both the gravimetric preparation of the CRM and the calibration of high-performance inductively coupled plasma optical emission spectrometry (ICP-OES) measurements. On the other hand, INM(CO) used gravimetric titration with EDTA to assay cadmium in the CRM solutions. The EDTA salt was previously characterized by titrimetry. Despite the fundamentally different measurement methods and independent metrological traceability paths to the SI, the measurement results exhibited excellent agreement within the stated uncertainties. This comparative analysis demonstrates the effectiveness of varied characterization approaches and underscores the reliability of the cadmium calibration solutions prepared by TÜBİTAK-UME and INM(CO). This collaborative effort highlights the reliability and adaptability of various measurement techniques in fulfilling rigorous metrological standards for elemental calibration solutions. Furthermore, this approach enhances the robustness of the measurements in the field of elemental analysis and contributes traceability to the SI.
metals from dietary supplements, introduced in USP (United States Pharmacopeia) «〈232〉Elemental Impurities—Limits» and USP «〈233〉Elemental Impurities—Procedures»
Inductively coupled plasma mass spectrometry (ICP-MS) is a type of mass spectrometry that uses an inductively coupled plasma to ionize the sample. It atomizes the sample and creates atomic and small polyatomic ions, which are then detected. It is known and used for its ability to detect metals and several non-metals in liquid samples at very low concentrations. It can detect different isotopes of
Cosmetics, such as lipstick, recovered from a crime scene may provide valuable forensic information. Lipstick smears left on cigarette butts, glassware, clothing, bedding; napkins, paper, etc. may be valuable evidence. Lipstick recovered from clothing or skin may also indicate physical contact between individuals. Forensic analysis of recovered lipstick smear evidence can provide valuable information on the recent activities of a victim or suspect. Trace elemental analysis of lipstick smears could be used to complement existing visual comparative procedures to determine the lipstick brand and color.
Single Particle Inductively Coupled Plasma Mass Spectroscopy (SP ICP-MS) was designed for particle suspensions in 2000 by Claude Degueldre. He first tested this new methodology at the Forel Institute of the University of Geneva and presented this new analytical approach at the 'Colloid 2oo2' symposium during the spring 2002 meeting of the EMRS, and in the proceedings in 2003. This study presents the theory of SP ICP-MS and the results of tests carried out on clay particles (montmorillonite) as well as other suspensions of colloids. This method was then tested on thorium dioxide nanoparticles by Degueldre & Favarger (2004), zirconium dioxide by Degueldre et al (2004) and gold nanoparticles, which are…
Inorganic impurity analysis of pharmaceutical drug products is of paramount importance at trace levels due to the availability of toxic metals. The existing techniques require extensive development and chemical treatment to evaluate the presence of class I (Pb, Cd, Hg and As) and class II (Co, V and Ni) heavy metal elements which are harmful to the environment. To overcome these issues, a cost and time effective wavelength dispersive X-ray fluorescence spectrometry (XRF) was introduced to determine the concentration of trace elements in one of the angiotensin receptor blocker (ARB) (tablet sample 300 mg) according to guidelines addressed in ICH Q3D and USP. The validation study focused on class I and class II elements are also in accordance with regulatory guidelines. Overall it includes the comprehensive characterization of analytical method which is compliant with the requirement of USP. The novelty of this work includes the application of EDXRF in routine analysis of trace elements (especially volatile Hg) present in the pharmaceutical product beyond the previously published studies for the limited number of the non-pharmaceutical regime. Apart from this it also requires minimal sample preparation and method development and is able to quantify toxic impurities which are present in the sample in less than 20 ppm concentration, with the lowest level of detection up to 0.1 ppm.
All regulatory organizations are paying close attention to the identification and measurement of genotoxic contaminants. Using conventional analytical techniques like high-performance liquid chromatography (HPLC) and gas chromatography to quantify probable genotoxic substances (PGIs) at the trace level is difficult (GC). Therefore, there is a necessity for advanced analytical techniques for the development of highly sensitive analytical procedures for the determination of trace-level PGIs in drug products and drug substances. This study’s goal is to develop and evaluate an analytical technique for measuring allyl chloride, a possible genotoxic contaminant in gemfibrozil. For the detection of very low and trace levels of impurities, a gas chromatography with a triple quadrupole mass spectrometry detector (GC-MS/MS) approach was developed and validated. Using a column USP phase G27, a nonpolar and low bleed 5% diphenyl, 95% dimethylpolysiloxane, with dimensions of 30 m in length, 0.32 mm internal diameters, and 1.5 m film thickness, along with a flow rate of 2.0 mL/min and Helium (He) as a carrier gas, this method uses a thermal gradient elution program. The method was calibrated with a linearity range from 30% to 150% concentration with respect to the specification level and achieved a limit of detection (LOD) and limit of quantification (LOQ) were 0.005 ppm and 0.01 ppm, respectively, for allyl chloride. According to current ICH requirements, the method was validated, and it
Abstract Sequence variants (SV) in protein bio therapeutics can be categorized as unwanted impurities and may raise serious concerns in efficacy and safety of the product. Early detection of specific sequence modifications, that can result in altered physicochemical and or biological properties, is therefore desirable in product manufacturing. Because of their low abundance, and finite resolving power of conventional analytical techniques, they are often overlooked in early drug development. Here, we present a case study where trace amount of a sequence variant is identified in a monoclonal antibody (mAb) based therapeutic protein by LC–MS/MS and the structural and functional features of the SV containing mAb is assessed using appropriate analytical techniques. Further, a very sensitive selected reaction monitoring (SRM) technique is developed to quantify the SV which revealed both prominent and inconspicuous nature of the variant in process chromatography. We present the extensive characterization of a sequence variant in protein biopharmaceutical and first report on control of sequence variants to < 0.05% in final drug product by utilizing SRM based mass spectrometry method during the purification steps.
Zinc oxide is a critical industrial material with extensive applications in galvanization, ceramics, electronics, and renewable energy systems. Despite China's vast zinc reserves (41 million tons), domestic production of primary zinc oxide from concentrates remains limited to 20%, with recycled materials contributing merely 11%. As a result, there is a heavy reliance on imported resources. This imbalance underscores the urgent need to optimize the utilization of secondary resources and adopt sustainable technologies. This review systematically examines recent advancements in zinc oxide smelting, enrichment, analytical characterization, and strategies for a circular economy. Modern hydrometallurgical techniques, such as high-temperature acid leaching and ammonia-ammonium carbonate systems, have achieved over 95% zinc recovery from low-grade ores. Innovations in pyrometallurgy, including microwave-assisted reduction and rotary kiln volatilization, have reduced energy consumption by approximately 30% while minimizing emissions. Advanced detection methods, such as X-ray fluorescence spectroscopy and combustion furnace-ion chromatography, enable precise monitoring of toxic elements, including lead, cadmium, and arsenic. Furthermore, circular economy approaches-such as slag geopolymerization and nano zinc oxide synthesis from industrial by-products demonstrate significant potential for waste valorization. By integrating interdisciplinary technologies, such as machine learning and biohydrometallurgy, this review outlines a potential roadmap toward a sustainable zinc industry, balancing economic growth with environmental responsibility.
Nitrosamine impurities belong to a class of probable carcinogens that are present in various pharmaceutical products and are also called as pharmaceutical contaminants. In this study 12 out of the most significant nitrosamine impurities were taken for quantitative determination in Valsartan tablet formulation that are commercially available in multiple strengths of 40mg, 80mg and 320mg etc. For acceptable intake and other relevant information, EMA and FDA guidelines were referred. The experiments in this work were performed as per current requirements in analytical chemistry where highly sophisticated analytical techniques are required such as LCMS/ MS to quantify trace levels of nitrosamine impurities in drug products. The results show that an appropriate method is required to be developed and validated for an accurate and reliable detection of nitrosamine impurities and that is what is performed in this study. Depending upon the Acceptable intake of 26.5 ng/day and 320mg of Maximum daily dose for Valsartan, 0.083 ppm (parts per million) was the specification limit. This kind of methodology supports routine product testing to ensure product safety and regulatory compliance.
Polymer electrolyte membrane fuel cells are sensitive to impurities. H2S at the ppb level will impact fuel cell performance. It is important to quantify H2S adsorption and issues such as permeation and crossover rates become extremely important. Experimental methods have been developed to quantify H2S adsorption onto surfaces and to quantify H2S permeation through Nafion® using common and inexpensive Ag/AgS ion-probes. In addition to calculating the H2S uptake on commonly used XC-72 and Pt/XC-72 materials, the H2S permeability through dry and humidified Nafion® membranes was also studied using specialized techniques. A sulfide anti-oxidant buffer solution was used to trap and concentrate trace quantities of H2S during the course of the measurement. Crossover experiments were conducted for up to 24 hours in order to achieve sulfide ion concentrations high enough to be precisely determined by subsequent titration. We have confirmed H2S crossover in Nafion® membranes and have calculated preliminary rates of crossover.
The physical principles and analytical capabilities of TXRF are discussed and compared to other surface sensitive techniques. Metallic trace impurities on silicon surfaces are readily identified with detection limits down to 1011 atoms/cm2 (10−4 monolayers). Other advantages are simple sample preparation and the possibility of analyzing insulating layers without charging problems. The method has been applied to quantify coverages of Fe, Ni, Cu and Au on Si(100) surfaces, deposited from intentionally doped solutions (NH3/H2O2 and HF/NH4F). It turns out that certain metal/solution combinations cause large surface coverages on the silicon wafer, even if the metal concentration in the solution is very low (μg/kg range).
Everything we examined (9)
This check searched the claim as stated. It did not run a separate search for evidence against it.