National Measurement Institute Australia Research Articles

Bilateral Comparison of High-Voltage Capacitance and Dielectric Dissipation Factor at 50 Hz

NIM (National Institute of Metrology, China) and NMIA (National Measurement Institute, Australia) carried out a comparison program, which included low-voltage capacitance, the voltage dependence of high-voltage capacitance and the dielectric dissipation factor (DDF) at 50 Hz. The travelling standards included a low-voltage standard capacitor, a dissipation factor standard and a 100 kV compressed-gas capacitor. The capacitance and DDF of the standard capacitor, measured by the two institutes, agreed within 2 μF/F and 2×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-6</sup> , respectively, at 50 Hz and 500 V. DDF measurements at nominal values of 0.00000, 0.0001 and 0.001 agreed within 6×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-6</sup> at 50 Hz and 10 kV. The capacitance change of a 100 kV compressed-gas capacitor measured by the two institutes agreed within 2 μF/F over the voltage range from 10 kV to 100 kV. The success of the program proved comparisons using a re-filled high-voltage compressed gas capacitor and a low-voltage standard capacitor can be conveniently used to validate the complete traceability chain of the measurement of high-voltage capacitance at 50 Hz. The program also proved that DDF measurements with different implementations of traceability chain via capacitance and resistance would agree well within the uncertainties required by industrial measurements and a commercial DDF standard that has undergone international air travel would be sufficiently stable.

Quasi-continuous dc voltage standard using sinusoidal and pulse-driven Josephson junction arrays

Josephson voltage standards (JVSs) provide a primary realization of the volt, the unit of electromotive force. They generate direct current (dc) voltages up to 10 V and show agreement better than 1 nV V−1 at 10 V. For JVSs based on Josephson junction arrays (JJAs) that are driven by sinusoidal radiofrequency (RF) power, commonly referred to as continuous wave-driven JJAs (CWD JJAs), the minimum voltage that can be generated is limited to the voltage across one Josephson junction (JJ) for practical devices. To achieve this resolution, they may require a perfect JJA chip. JVSs based on a pulse-driven (PD) JJA require high performance electronics (i.e. high bandwidth, low distortion and jitter, pulse shaping filters and large memory) to achieve their minimum and maximum voltage. We have combined two CWD JJAs and two PD JJAs driven by two microwave inputs to one chip to generate quasi-continuous dc voltages up to the sum of the full-scale voltages of both JJAs that are robust to the imperfections of the JJs and have relaxed requirements on the RF electronics driving the JJA, compared to the existing CWD JVSs and PD JVSs, respectively. By use of the JJA chip at the National Measurement Institute Australia, we demonstrate its feasibility to generate voltages up to 1 V. Preliminary evaluation of the system shows that the voltage uncertainty can be 11 nV (k = 2) or better and the theoretical resolution is better than 1 nV from 0 V to 1 V. The main requirement is that all the JJs must have quantum locking ranges with respect to the power and frequency of the RF bias and for the PD JJAs to have a constant voltage over a range of dc bias current. Although this development is not a replacement for existing state-of-the-art JVSs, we anticipate that it will be an alternative fit-for-purpose solution for metrological applications under non-ideal operating conditions or when the components of the state-of-the-art solutions are not available.

An isotope dilution LC–MS/MS-based candidate reference method for the quantification of androstenedione in human serum and plasma

The accurate measurement of androstenedione in human serum and plasma is required for steroid profiling to assure the appropriate diagnosis and differential diagnosis of hyperandrogenism. In this work, we introduce an isotope dilution liquid chromatography–tandem mass spectrometry (LC–MS/MS) candidate reference measurement procedure for the quantification of androstenedione in human serum and plasma. The performance of the procedure enables its use in the evaluation and standardization of routine assays and for the evaluation of patient samples to ensure the traceability of individual patient results. As the primary standard, a certified reference material from NMIA (National Measurement Institute, Australia) was used. Additionally, a quantitative nuclear magnetic resonance (qNMR) method was developed for the value assignment of the primary reference material, which ensures the direct traceability to SI units, as well as the independence from the availability of reference materials. 13C3-labeled androstenedione was used as the internal standard. The introduced method allows the measurement of androstenedione in the range of 0.05–12 ng/mL, and the assay imprecision was found to be <2% between 5 and 12 ng/mL, 3.5% at 1.5 ng/mL, and 5.2% at 0.05 ng/mL, with an accuracy of 95–105% for the serum and 91–103% for the plasma matrix. The transferability to a second laboratory was validated by method comparison based on 112 patient samples. The comparison of the results obtained from the presented method and an LC–MS/MS routine assay, using 150 native patient samples, showed a good correlation with a bias of the routine method of ≤4.0%.

APMP key comparison of absolute pressure from 10 kPa to 110 kPa (APMP.M.P-K9)

This report describes the results of a key comparison of pneumatic pressure standards which was carried out at fourteen National Metrology Institutes (NMIs: NMIA, NSCL, PTB, NIM, VMI, CMS/ITRI, MSL, NMIJ/AIST, NMC A*STAR, NIMT, SCL, NIS, RCM-LIPI and KRISS) during the period of February 2010 to July 2012 within the framework of the Asia-Pacific Metrology Programme (APMP) in order to determine their degrees of equivalence at pressures in the range 10 kPa to 110 kPa in absolute mode. Among them, twelve NMIs' results were compared in the report. The pilot laboratory was Korea Research Institute of Standards and Science (KRISS). The degrees of equivalence in this comparison were transferred to the corresponding CC key comparison, CCM.P-K2. National Measurement Institute, Australia (NMIA) and Physikalisch-Technische Bundesanstalt (PTB) that participated in the CC comparison agreed to be link laboratories.Most of the participating institutes used pneumatic pressure balances as their pressure standards while two link laboratories used laser interferometer mercury manometers. Precise absolute pressure gauges were used as transfer standards (TSs). The precision pressure gauge has two Quartz-Resonant Pressure Transducers (Q-RPTs) inside. Two identical transfer packages (TS-A and TS-B) were circulated independently to reduce the time required for the measurements. During the comparison, intermediate measurements of two circulated transfer standards were carried out in the pilot laboratory after one or two NMIs measurement and third transfer standard (TS-C) was monitored for the stability characterization, also. The pressures of the comparison were (10, 30, 50, 70, 90, 100, 110) kPa. From the calibration results, the behaviours of the transfer standards during the comparison period were well characterized and it was concluded that the performance of the transfer standards were sufficient in the comparison pressure range except 10 kPa. The TSs used in this comparison were not suitable for the low pressure measurement like 10 kPa because of low display resolution of TS (1 part in 105 at 10 kPa). The degrees of equivalence of each national measurement standard were expressed quantitatively by two terms, deviations from the key comparison reference values (KCRVs) and pair-wise differences of their deviations together with the associated uncertainties. The pneumatic pressure standards in the range 30 kPa to 110 kPa for absolute mode of all participating NMIs were found to be equivalent within their claimed uncertainties.Main textTo 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 CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Comparison of standards for the calibration of voltage, current and resistance meters

The 14th Meeting of the APMP Technical Committee on Electricity and Magnetism, held on 5 December 2011 in Kobe, Japan, decided to hold a comparison of standards for the calibration of voltage, current and resistance meters at the lowest attainable level of uncertainty. Our comparison, designated APMP.EM-S12, covered the parameters and ranges that would typically be measured during the calibration of digital multimeters in electrical laboratories. The instrument selected for the comparison was a Wavetek model 4950 Multifunction Transfer Standard.Circulation of the travelling standard started in February 2015 and the comparison concluded in October 2016. Between each of the comparison rounds the travelling standard was returned to the National Measurement Institute, Australia (NMIA). The dependence of the instrument on temperature and humidity was determined before the start of the comparison. The drift of the instrument during the comparison was determined from measurements at the NMIA. Participant results were corrected for temperature and drift.Comparison reference values were calculated from all participant results that survived outlier detection. Most of the results show good agreement with the comparison reference values.Main textTo 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 CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Measurement of the Nonlinearity of Heat-Flux Sensors Employing a $$\hbox {CO}_2$$ CO 2 laser

Heat-flux sensors are widely used in industry to test building products and designs for resistance to bushfire, to test the flammability of textiles and in numerous applications such as concentrated solar collectors. In Australia, such detectors are currently calibrated by the National Measurement Institute Australia (NMIA) at low flux levels of 20 W $$\cdot $$ m $$^{-2}$$ . Estimates of the uncertainty arising from nonlinearity at industrial levels (e.g. 50 kW $$\cdot $$ m $$^{-2}$$ for bushfire testing) rely on literature information. NMIA has developed a facility to characterize the linearity response of these heat-flux sensors up to 110 kW $$\cdot $$ m $$^{-2}$$ using a low-power $$\hbox {CO}_2$$ laser and a chopped quartz tungsten–halogen lamp. The facility was validated by comparison with the conventional flux-addition method, and used to characterize several Schmidt–Boelter-type sensors. A significant nonlinear response was found, ranging from ( $$3.2 \pm 0.9$$ )% at 40 kW $$\cdot $$ m $$^{-2}$$ to more than 8 % at 100 kW $$\cdot $$ m $$^{-2}$$ . Additional measurements confirm that this is not attributable to convection effects, but due to the temperature dependence of the sensor’s responsivity.

A suite of capacitors of fixed values for use with the new calculable cross capacitor and measurement system at the National Measurement Institute Australia

A suite of capacitors of fixed values for use with the new calculable cross capacitor and measurement system at the National Measurement Institute Australia has been constructed. One set of capacitors, of values 5, 10, 20 and 50 pF, is of Invar construction; a second set, of values 50, 100, 200 and 500 pF, is comprised of fused silica elements. In the case of the Invar capacitors, an analytical calculation of capacitance has been derived that facilitates the design process.

CCQM-K104 key comparison (avermectin B1a) on the characterization of organic substances for chemical purity

Under the Comité Consultatif pour la Quantité de Matière (CCQM), a key comparison, CCQM-K104, was coordinated by the National Institute of Metrology (NIM). The comparison was designed to demonstrate a laboratory's performance in determining the mass fraction of the main component in a complex high purity organic material. Nine NMIs or DIs participated in the comparison. Eight participants reported their results. An additional impurity was resolved from the avermectin B1a peak and was tentatively identified as an unknown impurity by NMIA (National Measurement Institute (Australia)). It was subsequently identified by NIM as a diastereoisomer of avermectin B1a at the C-26 position. Final reference value (KCRV) = 924.63 mg/g, with uncertainty (k=1) = 3.89 mg/g, and expanded uncertainty = 8.97 mg/g. The degrees of equivalence with the avermectin B1a KCRV for each participant were reported. The measurement results and degrees of equivalence should be indicative of the performance of a laboratory's measurement capability for the purity assignment of organic compounds of high structural complexity (relative molecular mass range of 500 Da -1000 Da and low polarity (-log KOW ⩽ -2).Main textTo 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).

Identification and characterization of N-tert-butoxycarbonyl-MDMA: a new MDMA precursor.

In September 2015, 80 litres of a viscous, light-red liquid, described as hair product, was seized by the Australian Border Force (ABF). Initial testing by ABF indicated that the liquid was the 3,4-methylenedioxymethamphetamine (MDMA) precursor chemical safrole and custody of the material was transferred to the Australian Federal Police (AFP) who coordinated all subsequent investigations. Initial gas chromatography-mass spectrometry (GC-MS) analysis by the AFP indicated that the material was not safrole and samples of the liquid were transferred to the National Measurement Institute Australia (NMIA) for identification. Using a combination of nuclear magnetic resonance spectroscopy (NMR), GC-MS, infrared spectroscopy, and synthesis, the unknown substance was identified as N-tert.-butoxycarbonyl-MDMA (t-BOC-MDMA). The substance was also converted in high yield to MDMA (aqueous HCl, 80 °C, 30 min). The possibility that the t-BOC-MDMA may act as a pro-drug following ingestion was explored by exposure to simulated gastric juice (pH 1.5) and monitored by NMR (37 °C) at various intervals. The majority of t-BOC-MDMA was converted to MDMA after 305 min, which suggested that this derivatized form might serve as a pro-drug in vivo. An investigation into the chemistry of potential pro-drugs showed that t-BOC derivatives of methamphetamine, pseudoephedrine and 4-methylmethcahtinone (mephedrone) could also be prepared using di-tert.-butyl dicarbonate. The appearance of t-BOC-derivatives on the drug market requires further monitoring. © 2016 Commonwealth of Australia. Drug Testing and Analysis © 2016 John Wiley & Sons, Ltd.

Production of trace elements in coastal sea water certified reference material NMIA MX014.

A certified reference material (CRM) for trace elements in acidified sea water, NMIA MX014, has been produced by the National Measurement Institute Australia (NMIA). The CRM consists of natural coastal sea water with 12 elements (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se and V) fortified to levels relevant to environmental regulatory testing in Australia ranging from 0.4 to 22μg/kg. Certified values for these 12 elements were assigned using reference methods developed at NMIA, using either isotope dilution or standard addition with ICP-MS measurement. Specialised sample preparation (coprecipitation) and ICP-MS optimisation (online dilution, collision/reaction chemistry, high mass resolution) were used to negate the effect of the high level of dissolved solids. Multiple confirmatory experiments were performed in order to verify that ICP-MS spectral interferences were eliminated and to estimate the measurement uncertainty contribution from method precision and method trueness. Extensive homogeneity and stability testing was performed and the measurement uncertainty of certified values includes contributions from between-bottle homogeneity, short-term stability, medium-term stability and long-term stability. Special attention was paid to the stability of Hg due to well-known preservation problems. Acidified sea water matrix was satisfactory for stabilising Hg at 0.4μg/kg for at least 4years. Relative expanded uncertainties (k = 2) for the 12 certified values were between 1 and 11%. NMIA MX014 is intended for use as a reference material for analytical method validation and quality control for quantification of trace elements in saline water and other similar sample types.

Handheld Reflective Foil Emissometer with 0.007 Absolute Accuracy at 0.05

The development and performance of a handheld emissometer for the measurement of the emissivity of highly reflective metallic foils used for the insulation of domestic and commercial buildings are described. Reflective roofing insulation based on a thin coating of metal on a more robust substrate is very widely used in hotter climates to reduce the radiant heat transfer between the ceiling and roof in commercial and residential buildings. The required normal emissivity of these foils is generally below 0.05, so stray reflected ambient infrared radiation (IR) makes traditional reflectance-based measurements of emissivity very difficult to achieve with the required accuracy. Many manufacturers apply additional coatings onto the metallic foil to reduce visible glare during installation on a roof, and to provide protection to the thin reflective layer; however, this layer can also substantially increase the IR emissivity. The system as developed at the National Measurement Institute, Australia (NMIA) is based on the principle of measurement of the modulation in thermal infrared radiation, as the sample is thermally modulated by hot and cold air streams. A commercial infrared \(8\,\upmu \hbox {m}\) to \(14\,\upmu \hbox {m}\) band radiation thermometer with a highly specialized stray and reflected radiation shroud attachment is used as the detector system, allowing for convenient handheld field measurements. The performance and accuracy of the system have been compared with NMIA’s reference emissometer systems for a number of typical material samples, demonstrating its capability to measure the absolute thermal emissivity of these very highly reflective foils with an uncertainty of better than \(0.007, k = 2.07, 95\,\%\) .

Comparative studies on the antioxidant properties and polyphenolic content of wine from different growing regions and vintages, a pilot study to investigate chemical markers for climate change

Many health benefits of wine result from specific polyphenolic compounds. Factors such as climate, CO2 levels and region are known to affect polyphenolic compounds in wine; therefore a pilot study was conducted to focus on the Australian climate which has shifted from El Niño to La Niña. This research paper presents the influence of climate conditions and growing regions on the in vitro and ex vivo antioxidant capacity of red and white wine and the profile and concentration of polyphenols in these wines from the 2008 and 2009 vintages. The ORAC and polyphenolic data show that warmer climate wines had lower in vitro antioxidant capacity values but retained good bioavailability based on data from the RBC ex vivo assay compared to cool climate wines. Based on this pilot study, further research is being conducted at the National Measurement Institute, Australia (NMIA) with the goal of determining more polyphenolic compounds which appear to be affected by climate conditions.

DENSITY MEASUREMENT OF ETHANOL BLENDED FUELS

Density measurements for petro-ethanol blended fuels of various mixture ratios were conducted at temperatures from 5°C to 40°C using an oscillatory densitometer at the National Measurement Institute, Australia (NMIA). The petrol and ethanol fuels used for the preparation of samples of ethanol blends were supplied directly from a local petroleum refinery. Results were within the lower end of 0.06% repeatability and 0.3% reproducibility of the ASTM D4052-2011 method. The volume correction factors (VCF) for petrol and ethanol obtained from the measurement results agreed to within 0.1% and 0.01% of the values calculated as per American Petroleum Institute Standard 2540 Chapter 11.1 and 11.3.3 respectively. Based on a simple volume-mixture model, an equation was derived to calculate the VCF for petrol-ethanol blends. The measured and calculated values of VCF were in agreement within 0.1%. This paper presents the measurement method, results and the development of an equation for calculation of VCF for petro-ethanol blends. Note from Publisher: This article contains the abstract only.

A multinational joint project on the evaluation of residual pesticide analysis in tea in the Asia Pacific region

This paper presents the results of a multinational joint proficiency testing (PT) programme on four pesticide residues (cypermethrin, α-endosulfan, β-endosulphan and bifenthrin) in two tea samples. The objectives were to evaluate the performance and to improve the testing capability of field laboratories in the Asia Pacific region for analysis of pesticide residues in tea. A total of 42 laboratories registered for the programme and 32 laboratories from 12 economies returned the results to the organizers. The assigned values of the pesticides were agreed to be the respective weighted mean determined by the three metrology institutes — the National Measurement Institute, Australia (NMIA), the National Institute of Metrology, China (NIM) and the Government Laboratory, Hong Kong (GLHK) in an Asia Pacific Metrology Programme (APMP) pilot study programme (APMP.QM-P15) using the same test materials. The performance of participating laboratories was expressed using the numerical indicators of z-scores and En-scores. Amongst the reported data, only 35.3% and 35.0% achieved satisfactory z-scores (|z|≤2) and En-scores (|En|≤1) respectively. Only two laboratories achieved satisfactory z-scores and En-scores for all the analytes. The results demonstrated that the performance of the majority of the laboratories participating in this study on the analysis of pesticide residues in tea was not satisfactory, and more capability building is required for further improvement.

Certification of steroid carbon isotope ratios in a freeze‐dried human urine reference material

An accurate method for the measurement of carbon isotope ratios of steroids in human urine has been developed at the National Measurement Institute, Australia (NMIA) for the certification of a freeze-dried human urine reference material (CRM NMIA MX005). The method measures δ(13)C values by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) analysis following hydrolysis, solvent extraction and high performance liquid chromatography (HPLC) purification. Reference δ(13)C values for testosterone metabolites etiocholanolone, androsterone, and endogenous reference compounds (ERCs) 11β-hydroxyandrosterone and pregnanediol were determined, as well as information δ(13)C values for testosterone, epitestosterone, 11-oxoetiocholanolone, and a range of differences (Δ(13)C) between testosterone metabolites and ERCs. The measurement uncertainty was rigorously evaluated with expanded uncertainties for the reference δ(13)C values between 1.1 and 1.6 ‰ at the 95% coverage level.

Metrological scanning probe microscope based on a quartz tuning fork detector

We give an overview of the design of a metrological scanning probe microscope (mSPM) currently under development at the National Measurement Institute Australia (NMIA) and report on preliminary results on the implementation of key components. The mSPM is being developed as part of the nanometrology program at NMIA and will provide the link in the traceability chain between dimensional measurements made at the nanometer scale and the realization of the International System of Units (SI) meter at NMIA. The instrument is based on a quartz tuning fork (QTF) detector and will provide a measurement volume of 100 μm×100 μm×25 μm with a target uncertainty of 1 nm for the position measurement. Characterization results of the nanopositioning stage and the QTF detector are presented along with an outline of the method for tip mounting on the QTFs. Initial imaging results are also presented.

Final report on key comparison CCQM-K55.b (aldrin): An international comparison of mass fraction purity assignment of aldrin

Under the auspices of the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM) a key comparison, CCQM K55.b, was coordinated by the Bureau International des Poids et Mesures (BIPM) in 2010/2011. Nineteen national measurement institutes and the BIPM participated. Participants were required to assign the mass fraction of aldrin present as the main component in the comparison sample for CCQM-K55.b which consisted of technical grade aldrin obtained from the National Measurement Institute Australia that had been subject to serial recrystallization and drying prior to sub-division into the units supplied for the comparison.Aldrin was selected to be representative of the performance of a laboratory's measurement capability for the purity assignment of organic compounds of medium structural complexity [molar mass range 300 Da to 500 Da] and low polarity (pKOW < −2) for which related structure impurities can be quantified by capillary gas phase chromatography (GC).The key comparison reference value (KCRV) for the aldrin content of the material was 950.8 mg/g with a combined standard uncertainty of 0.85 mg/g. The KCRV was assigned by combination of KCRVs assigned by consensus from participant results for each orthogonal impurity class. The relative expanded uncertainties reported by laboratories having results consistent with the KCRV ranged from 0.3% to 0.6% using a mass balance approach and 0.5% to 1% using a qNMR method.The major analytical challenge posed by the material proved to be the detection and quantification of a significant amount of oligomeric organic material within the sample and most participants relying on a mass balance approach displayed a positive bias relative to the KCRV (overestimation of aldrin content) in excess of 10 mg/g due to not having adequate procedures in place to detect and quantify the non-volatile content—specifically the non-volatile organics content—of the comparison sample.There was in general excellent agreement between participants in the identification and the quantification of the total and individual related structure impurities, water content and the residual solvent content of the sample.The comparison demonstrated the utility of 1H NMR as an independent method for quantitative analysis of high purity compounds. In discussion of the participant results it was noted that while several had access to qNMR estimates for the aldrin content that were inconsistent with their mass balance determination they decided to accept the mass balance result and assumed a hidden bias in their NMR data. By contrast, laboratories that placed greater confidence in their qNMR result were able to resolve the discrepancy through additional studies that provided evidence of the presence of non-volatile organic impurity at the requisite level to bring their mass balance and qNMR estimates into agreement.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).

Final report on APMP key comparison of volume of liquids at 20 L and 100 mL: APMP.M.FF-K4

This report presents the results of a key comparison of liquid volume measurement conducted between ten participating institutes during the period July 2006 to August 2008 within the framework of the Asia Pacifica Metrology Program (APMP). The transfer standards comprised one 20 L volume measure and two 100 mL glass pycnometers. These transfer standards had been used in a similar CIPM key comparison CCM.FF-K4 in 2003 to 2005. The pilot institute was the National Measurement Institute, Australia (NMIA), which together with CENAM act as link laboratories to the CCM.FF-K4 comparison.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 CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Final report on CCQM-K69 key comparison: Testosterone glucuronide in human urine

The CCQM-K69 key comparison of testosterone glucuronide in human urine was organized under the auspices of the CCQM Organic Analysis Working Group (OAWG). The National Measurement Institute Australia (NMIA) acted as the coordinating laboratory for the comparison. The samples distributed for the key comparison were prepared at NMIA with funding from the World Anti-Doping Agency (WADA). WADA granted the approval for this material to be used for the intercomparison provided the distribution and handling of the material were strictly controlled.Three national metrology institutes (NMIs)/designated institutes (DIs) developed reference methods and submitted data for the key comparison along with two other laboratories who participated in the parallel pilot study. A good selection of analytical methods and sample workup procedures was displayed in the results submitted considering the complexities of the matrix involved. The comparability of measurement results was successfully demonstrated by the participating NMIs. Only the key comparison data were used to estimate the key comparison reference value (KCRV), using the arithmetic mean approach. The reported expanded uncertainties for results ranged from 3.7% to 6.7% at the 95% level of confidence and all results agreed within the expanded uncertainty of the KCRV.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).

Development of a Measurement System for Certifying Ethanol Mass Fraction in Aqueous Solutions

In response to the sovereign requirement for national standards the National Measurement Institute, Australia (NMIA) has developed a measuring system using isotope dilution mass spectrometry (IDMS) to certify forensic aqueous ethanol solutions. NMIA participated in an international study, CCQM-K27, organized under the auspices of the International Committee for Weights and Measures to compare our measuring system with the techniques being used for certifying aqueous ethanol solutions in other metrology institutes. This comparison provided objective evidence that the measuring system developed was fit for the purpose of certifying aqueous ethanol solutions that ranged in concentration from 0.8 mg/g to 120 mg/g. A complete measurement uncertainty budget is presented and shows that the largest contribution to measurement uncertainty was from method precision followed by the contribution from the calibration solution. The fundamental technology of the measuring system was gas chromatography of the aqueous ethanol solutions using porous layer open tubular columns, and this effectively produced peak area measurements with both GC/MS and GC-FID. It was found that deactivation of the chromatographic system was critical for obtaining reproducible peak shapes and peak area measurements. A range of measuring systems, all using this gas chromatographic technology, was investigated. When conditions were carefully controlled there was no difference in measurement results from GC-IDMS, GC/MS or GC-FID. There was also no difference in results from on-column or split injection systems. A significant issue with the IDMS system was the fragmentation of 13C2-ethanol to produce an ion with the same mass as the molecular ion of ethanol which lead to isobaric interference; careful measurement of this fragmentation ratio was necessary to calculate accurate mass fraction values. NMIA has adopted the GC-IDMS split measuring system to certify aqueous ethanol solutions for Australian legal requirements since this measuring system provided higher analytical specificity than GC-FID, accuracy that was fit for purpose and was operationally less stringent than on-column techniques.