Sebastian Recknagel

Elemental analysis of printed circuit boards considering the ROHS regulations

The EU RoHS Directive (2002/95/EC of the European Parliament and of the Council) bans the placing of new electrical and electronic equipment containing more than agreed levels of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyl (PBB) and polybrominated diphenyl ether (PBDE) flame retardants on the EU market. It necessitates methods for the evaluation of RoHS compliance of assembled electronic equipment. In this study mounted printed circuit boards from personal computers were analyzed on their content of the three elements Cd, Pb and Hg which were limited by the EU RoHS directive. Main focus of the investigations was the influence of sample pre-treatment on the precision and reproducibility of the results. The sample preparation steps used were based on the guidelines given in EN 62321. Five different types of dissolution procedures were tested on different subsequent steps of sample treatment like cutting and milling. Elemental analysis was carried out using ICP-OES, XRF and CV-AFS (Hg). The results obtained showed that for decision-making with respect to RoHS compliance a size reduction of the material to be analyzed to particles ≤ 1.5mm can already be sufficient. However, to ensure analytical results with relative standard deviations of less than 20%, as recommended by the EN 62321, a much larger effort for sample processing towards smaller particle sizes might be required which strongly depends on the mass fraction of the element under investigation.

Determination of aluminium in infusion solutions by inductively coupled plasma atomic emission spectrometry—a critical comparison of different emission lines

Seven emission lines for the determination of Al in infusion solutions by means of inductively coupled plasma atomic emission spectrometry were compared. For this comparison, wavelength scans of different samples were made in order to study the background in the region of each line and to inspect for interference structures arising from molecular bands of water and argon. Background equivalent concentrations and detection limits were calculated for the emission lines at 167, 237, 394 and 396 nm. The detection limits were 1.2 µg l–1 for the 167 nm line, 8.8 µg l–1 for the 237 nm line, 10 µg l–1 for the 394 nm line, 4.7 µg l–1 for the 396 nm line and > 10 µg l–1 for the other three lines (226, 308 and 309 nm). The Al content of various infusion solutions was determined on different days using the three emission lines with the lowest detection limits (167, 237 and 396 nm). Day-to-day-variation was approximately 5% in all cases. As a final step, the Al contamination of 25 infusion solutions for parenteral nutrition was evaluated by using the two most suitable emission lines (167 and 396 nm). No statistically significant differences between the results were detected. Advantages and disadvantages of these two emission lines for the determination of Al are discussed.

Elemental analysis of copper and magnesium alloy samples using IR-laser ablation in comparison with spark and glow discharge methods

Three methods for direct solid sampling of bulk material namely IR laser ablation, glow discharge and spark OES, were compared with respect to analytical figures of merit obtained for elemental analysis with atomic spectrometry. Matrices investigated were copper, pressed doped copper powder, and magnesium alloys. For the vast majority of analytes, statistical equivalence regarding precision (usually ≤5%) and the performance of the calibrations between the compared methods was demonstrated.

Investigation on the heavy-metal content of zinc-air button cells.

Within the framework of a German government project (initiated by the Federal Environment Agency) to check the compliance of commercially available batteries with the German Battery Ordinance concerning their heavy metal contents, 18 different types of commercially available zinc-air button cells were analysed for their cadmium, lead and mercury contents. After microwave assisted dissolution with aqua regia, Cd and Pb were determined using inductively coupled plasma mass spectrometry (ICP-MS), and Hg was determined using inductively coupled plasma optical emission spectrometry (ICP OES) and atomic absorption spectrometry. Cd contents were found to be much lower than the permitted limits; Pb contents were also found to be below the limits. Hg contents were found to be near the limits, and in one case the limit was exceeded.

Investigation on the heavy metal content of zinc-carbon and alkaline manganese dry cells

The objective of this work was to test the compliance of commercially available batteries with the German Battery Ordinance, a project of the German government that was initiated by the Federal Environment Agency. Different types of commercially available dry cells were analysed for their cadmium, lead and mercury contents. The dry cells underwent mechanical pre-treatment, separation of the different components and microwave-assisted digestion before determination of the heavy metals. Mercury is sometimes added to prevent the generation of gaseous hydrogen from the electrochemical process. Lead could be present since it is sometimes used as an alloying element of zinc. Cadmium has no technical importance and is an undesirable impurity. None of the batteries contained higher heavy metal mass fractions than the permissible limits.

Survey of mercury, cadmium and lead content of household batteries.

The objective of this work was to provide updated information on the development of the potential impact of heavy metal containing batteries on municipal waste and battery recycling processes following transposition of the new EU Batteries Directive 2006/66/EC. A representative sample of 146 different types of commercially available dry and button cells as well as lithium-ion accumulators for mobile phones were analysed for their mercury (Hg)-, cadmium (Cd)- and lead (Pb)-contents. The methods used for preparing the cells and analysing the heavy metals Hg, Cd, and Pb were either developed during a former study or newly developed. Several batteries contained higher mass fractions of mercury or cadmium than the EU limits. Only half of the batteries with mercury and/or lead fractions above the marking thresholds were labelled. Alkaline-manganese mono-cells and Li-ion accumulators, on average, contained the lowest heavy metal concentrations, while zinc-carbon batteries, on average, contained the highest levels.

Final report on key comparison CCQM-K55.c (L-(+)-Valine): Characterization of organic substances for chemical purity

Under the auspices of the Organic Analysis Working Group (OAWG) of the Comit? Consultatif pour la Quantit? de Mati?re (CCQM) a key comparison, CCQM K55.c, was coordinated by the Bureau International des Poids et Mesures (BIPM) in 2012. Twenty National Measurement Institutes or Designated Institutes and the BIPM participated. Participants were required to assign the mass fraction of valine present as the main component in the comparison sample for CCQM-K55.c. The comparison samples were prepared from analytical grade L-valine purchased from a commercial supplier and used as provided without further treatment or purification. Valine was selected to be representative of the performance of a laboratorys measurement capability for the purity assignment of organic compounds of low structural complexity [molecular weight range 100?300] and high polarity (pKOW > ?2). The KCRV for the valine content of the material was 992.0 mg/g with a combined standard uncertainty of 0.3 mg/g. The key comparison reference value (KCRV) was assigned by combination of KCRVs assigned from participant results for each orthogonal impurity class. The relative expanded uncertainties reported by laboratories having results consistent with the KCRV ranged from 1 mg/g to 6 mg/g when using mass balance based approaches alone, 2 mg/g to 7 mg/g using quantitative 1H NMR (qNMR) based approaches and from 1 mg/g to 2.5 mg/g when a result obtained by a mass balance method was combined with a separate qNMR result. The material provided several analytical challenges. In addition to the need to identify and quantify various related amino acid impurities including leucine, isoleucine, alanine and ?-amino butyrate, care was required to select appropriate conditions for performing Karl Fischer titration assay for water content to avoid bias due to in situ formation of water by self-condensation under the assay conditions. It also proved to be a challenging compound for purity assignment by qNMR techniques. There was overall excellent agreement between participants in the identification and the quantification of the total and individual related structure impurities, water content, residual solvent and total non-volatile content of the sample. Appropriate technical justifications were developed to rationalise observed discrepancies in the limited cases where methodology differences led to inconsistent results. The comparison demonstrated that to perform a qNMR purity assignment the selection of appropriate parameters and an understanding of their potential influence on the assigned value is critical for reliable implementation of the method, particularly when one or more of the peaks to be quantified consist of complex multiplet signals. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Determination of Beryllium in the Primary Cooling Water of the BER II Research Reactor by Inductively Coupled Plasma Optical Emission Spectrometry and Zeeman Electrothermal Atomic Absorption Spectrometry

In modern swimming pool research reactors the stable isotope 9 Be from the neutron reflector made of metallic beryllium is converted into 10 Be via a (n, γ )-reaction. This isotope contaminates the primary cooling water as a corrosive of the reflector material and has to be monitored continually. Since 10 Be can only be determined with nuclear spectrometric methods after an extensive radiochemical procedure, an indirect two step procedure was worked out: ( a ) calculation of the specific 10 Be-activity from the accumulated radiation periods since installation of the reflector into the reactor and ( b ) determination of the total amount of beryllium in the cooling water by using a sufficiently sensitive analytical technique. Knowledge of both values allows the immediate calculation of the 10 Be contamination of the pool water. It is shown that the inductively coupled plasma optical emission spectrometry (ICP-OES) coupled with ultrasonic nebulization is applicable to the determination of beryllium in water samples in the sub-ppb region. Comparing the three different emission lines, 234.861 nm, 313.042 nm and 313.107 nm, the first one proved to be best suited for the above mentioned analytical problem. The Be determination in the reactor water samples was also carried out using electrothermal atomic absorption spectrometry (ETAAS) with longitudinal heating of the graphite tube and Zeeman background compensation. The samples were measured without matrix-modification using the 234.861 nm absorption line. Quality assurance for both analytical methods was done determining two reference water samples. Detection limits (3σ) were similarly low: 0.012 µg l -1 for ICP-OES and 0.005 µg l -1 for ETAAS. Parallel analysis of seven different reactor pool water samples using both methods showed concentration values in fairly good agreement. The concentrations obtained were in the range 0.02–0.46 µg l -1 and yielded 10 Be activities of 0.3–9 Bq l -1 .

CCQM-K33 Final Report: Determination of minor elements in steel

The key comparison CCQM-K33 was organized by the Inorganic Analysis Working Group of the CCQM to test the abilities of the national metrology institutes to measure the mass fractions of minor elements in steel. Elements to be analysed were Cr, Mn, Ni and Mo in low alloy steel. The National Metrology Institute of Japan (NMIJ), the National Institute of Standards and Technology (NIST) and the Federal Institute for Materials Research and Testing (BAM) acted as the coordinating laboratories. The participants used various measurement methods, though many of them used ICP-AES. Generally speaking, the agreement of the results was very good for each measurand. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM.

Report of the study CCQM-K64: Analysis of a copper alloy

The CCQM-K64 study was performed to demonstrate and document the measurement capabilities of national metrology institutes in the determination of main and minor elements in copper alloys. The key comparison was coordinated by BAM Federal Institute for Materials Research and Testing, Berlin, Germany as an activity of the Inorganic Analysis Working Group of CCQM. Elements to be determined were Cu, Pb, Sn, Fe and Ni in a lead-containing brass. Five national metrology institutes registered to participate in CCQM-K64. Three of them analysed all five elements requested, two of them did not perform analyses for tin. The participants used different analytical methods: all of them seem to be suitable, especially for Cu determination. The BAM reference material AKP 220/2 Special Brass (unknown to the participants) was used as a test sample in this study. CCQM-K64 demonstrates the abilities of metrological institutes to measure the mass fractions of main, minor and trace components of a copper alloy for copper (main element, >50% mass fraction), lead (minor element, 1% to 5% mass fraction) and iron, nickel and, with reservations, tin (as trace components, 0.01% to 0.5% mass fraction). Only three of the five participants determined tin. The analytical methods used were electrogravimetry (for copper and lead), flame-AAS and ICP-MS. The scope of the key comparison extends to other copper alloys comprising the same or similar constituents and other elements in the same mass fraction range when analysed using the technique(s) applied in CCQM-64. It extends also to other non-ferrous metal alloys if the sample preparation is similar. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).