International Proficiency Testing Research Articles

Comparability of reading tasks in high-stakes English proficiency tests and university courses in Korea

With the increased popularity of English-medium instruction (EMI) in higher education, many East Asian universities are using international English proficiency tests to make admissions and placement decisions. Since these tests were not originally designed for the EMI contexts, validity evidence is needed to support the use of these tests in this new context. To interpret performance on a test as representative of performance in a target language use (TLU) domain, this study investigated (1) the characteristics of English reading tasks in Korean EMI undergraduate and graduate courses, (2) the extent to which they are comparable to the characteristics of reading tasks on TOEFL iBT and IELTS, and (3) the extent to which students perceive EMI reading tasks and the test reading tasks to be comparable. Fifty-four undergraduate and graduate students in EMI content courses at a Korean university completed an online questionnaire. Analyses revealed that EMI reading tasks share several characteristics with USA/UK university reading tasks. Although EMI reading tasks had some key characteristics in common with TOEFL and IELTS reading tasks, the test tasks were much more limited in range. Finally, the extent to which students perceived EMI reading tasks and TOEFL/IELTS reading tasks comparable varied across academic areas.

The Development, Validation, and Application of a UHPLC-HESI-MS Method for the Determination of 17 Cannabinoids in Cannabis sativa L. var. sativa Plant Material.

Cannabinoids are an important group of secondary metabolites found in the plant Cannabis sativa L. The growing interest in the use of hemp in food production (e.g., hemp teas, hemp cookies) makes it necessary to develop a method for determining these compounds in the plant, both fresh and dried. The selection of a suitable extraction liquid for the extraction of cannabinoids and the development of a method for the determination of 17 cannabinoids is a prelude to the development of an effective method for the extraction of these compounds. In the present study, a novel, simple, and efficient method was developed and validated for the determination of up to 17 cannabinoids in fresh plant parts (inflorescences and leaves) of Cannabis sativa L. and in dried material, including hemp teas. Analyses were performed using ultra-high-performance liquid chromatography-Q-Exactive Orbitrap mass spectrometry setup operating with a heated electrospray interface (UHPLC-HESI-MS). Based on the comparison, methanol was selected as the best for the extraction of cannabinoids from fresh and dried material. The efficiency and validity of the method were assessed using certified reference material (dried Cannabis) and confirmed by z-score from participation in an international proficiency test conducted by ASTM International for dried hemp.

Diverse types of expertise in facial recognition

Facial recognition errors can jeopardize national security, criminal justice, public safety and civil rights. Here, we compare the most accurate humans and facial recognition technology in a detailed lab-based evaluation and international proficiency test for forensic scientists involving 27 forensic departments from 14 countries. We find striking cognitive and perceptual diversity between naturally skilled super-recognizers, trained forensic examiners and deep neural networks, despite them achieving equivalent accuracy. Clear differences emerged in super-recognizers’ and forensic examiners’ perceptual processing, errors, and response patterns: super-recognizers were fast, biased to respond ‘same person’ and misidentified people with extreme confidence, whereas forensic examiners were slow, unbiased and strategically avoided misidentification errors. Further, these human experts and deep neural networks disagreed on the similarity of faces, pointing to differences in their representations of faces. Our findings therefore reveal multiple types of facial recognition expertise, with each type lending itself to particular facial recognition roles in operational settings. Finally, we show that harnessing the diversity between individual experts provides a robust method of maximizing facial recognition accuracy. This can be achieved either via collaboration between experts in forensic laboratories, or most promisingly, by statistical fusion of match scores provided by different types of expert.

IDIOMATIC POTENTIAL OF ANATOMICAL TERMINOLOGY AND ITS ROLE IN DEVELOPING ENGLISH LANGUAGE PROFICIENCY

The article examines the idiomatic features of anatomical terminology in modern English. The authors emphasize that understanding and correct use of idiomatic expressions is an indicator of in-depth knowledge of a foreign language and an important element in preparing for international English language exams, in particular, with the aim of recognizing implicit meanings (C1 – Advanced, C2 – Proficiency levels). It has been noted that mastering idiomatic expressions constitute one of the most difficult challenges for speakers of other languages, therefore it requires additional attention during the foreign language training of students. Based on the analysis and systematization of lexicographic sources (The Oxford Dictionary of Idioms, A Dictionary of 3800 Picturesque Idiomatic Expressions, and McGraw-Hill's Dictionary of American Idioms and Phrasal Verbs), it has been shown that anatomical terminology has significant idiomatic potential and is widely reflected in the figurative language of modern English. The study has revealed 628 idioms based on 52 anatomical terms, among which the lexemes “head”, “hand”, “eye”, “heart” and “foot” have the most productive idiomatic potential, forming the core of 75, 70, 53, 46 and 43 idioms respectively. The developed corpus of anatomical idioms has been organized for meaningful and accessible use in the educational process at a medical university. Familiarizing students with English anatomical idioms in the course of ESP training contributes to the development of student's interest and motivation in learning a foreign language, broadening their outlook, and ensuring an in-depth understanding of the mechanisms of English figurative language, which is the key to successfully passing international proficiency tests and communicating in a foreign language environment.

A study of Test-Taking strategies of Iranian IELTS repeaters: Any change in the strategy use?

This study used Latent Growth Curve Modeling (LGCM) to examine the overtime patterns of the score and test-taking strategy changes in an international high-stakes standardized proficiency test. To this end, the test records of 178 Iranian IELTS repeaters were analyzed, using close- and open-ended questionnaires to measure test scores as a function of construct-relevant and construct-irrelevant test-taking strategy changes. Additionally, this study explored the accountable factors for the changes in the repeaters’ strategies. Results indicated a small and gradual increase in the test scores following an overall augmented use of test-management (TM) and a decreased employment of test-wiseness (TW) strategies. Along with contributing to IELTS validity evidence based on the repeaters’ scores, this study found multiple sources to account for the changes in repeaters’ test-taking strategies. Consideration of changes in repeaters’ test-taking strategies by IELTS instructors and test users may add to the validity of interpretation of test scores to the intended purposes of the tests.

Non-targeted authentication of black pepper using a local web platform: Development, validation and post-analytical challenges of a combined NIR spectroscopy and LASSO method

Black pepper is a valuable commodity susceptible to economically motivated adulterations. This contribution describes the proper development, standardization, validation and late-stage validation of a non-targeted method for authentication of black pepper by near-infrared spectroscopy (NIR) coupled to a least absolute shrinkage and selection operator (LASSO). Note that this is the first successful attempt to apply the LASSO method to infrared spectroscopy data. We analysed 150 diverse samples of black pepper supplied by a well-recognized spice trader. A first batch of samples (n = 116) were split into training and test sets and then normalized by multiplicative scatter correction (MSC). While the test set was withheld for further testing of the model, the training set was submitted to the LASSO method with the aim of retrieving the discriminant spectral features and classifying the samples as authentic, exogenously-adulterated or endogenously-adulterated. The model was tested on the test set, achieving an overall accuracy of 94% with very high sensitivity and specificity rates. Furthermore, an R-based local web platform was created for immediate prediction of the samples from raw data. The NIR user simply uploads the raw data to the local web application and MSC normalization on the stored training set and interrogation of the LASSO classifier are performed. The online application facilitates the model testing and enables clear visualization of the outcomes. After the creation of the local web platform, the classifier was then validated with a new batch of independent samples, resulting in the correct prediction of 33/34 samples. The robustness of this non-targeted method and its stability over time was further established, and a late-stage validation of the classifier was successfully performed by an inexperienced user. Finally, the LASSO classifier was successfully challenged with a sample from an international inter-laboratory proficiency test. • A non-targeted method for authentication of black pepper by NIR & LASSO. • A web application was created for direct classification of NIR raw data. • Validation and late-stage challenges of the method were carried out. • Successful participation to an international proficiency test.

New approach for barbiturates, phenytoin, methyprylon and glutethimide determination and fragmentation (UHPLC-MS/MS)

Barbiturates which are old pharmaceutical drugs are still widely used in medical treatment of epilepsy and for general anesthesia. To date, more than 2500 different barbituric acid analogs have been synthesized, and 50 of them were introduced into medical use over the last century. Due to their highly addictive properties, pharmaceuticals containing barbiturates are under strict control in many countries. However, by considering the worldwide problem with new psychoactive substances (NPS) the introduction of new designer barbiturate analogs into the dark market might serve a serious public health problem in the near future. For this reason there is an increasing need for application methods for barbiturates monitoring in biological samples. The UHPLC-QqQ-MS/MS method for determination of 15 barbiturates, phenytoin, methyprylon and glutethimide was developed and fully validated. The biological sample volume was reduced to only 50 µL. A simple LLE (pH 3 with ethyl acetate) was successfully applied. The lower LOQ was 10 ng/mL. The method enables differentiation of structural isomers: hexobarbital and cyclobarbital; as well as amobarbital and pentobarbital. Chromatographic separation was achieved with the use of the alkaline mobile phase (pH 9) and Acquity UPLC BEH C18 column. Furthermore, the novel fragmentation mechanism of barbiturates was proposed, which may have a great impact in identification of novel barbiturates analogs introduced to illegal marketplaces. The presented technique has a great potential to be applied in forensic, clinical and veterinary toxicological laboratories, as was evidenced by the positive results of international proficiency tests.

Evaluation of 19years of international external proficiency testing for high-resolution HLA typing.

The international high-resolution external proficiency testing (EPT) started in 2004 with high-resolution typing of human leucocyte antigen (HLA) class I (HLA-A,B,C) and HLA class II (HLA-DRB1, DRB345, DQB1, and DPB1) alleles, since possibilities for such an EPT within Europe were limited and all existing EPTs at that time made use of the comparison of HLA typing results without a reference. This EPT was set up as a collaboration between the HLA laboratory of Leiden, providing DNA samples to the participants, and the laboratory of Maastricht, performing the high-resolution typing as the reference result and evaluating the results of all participants according to the prevailing European Federation for Immunogenetics (EFI) standards. Once a year, 12 samples were sent to the participating laboratories, and evaluation and certificates were provided at the end of that same year. During the years, the EPT was extended to low-resolution HLA class I and II typing, high-resolution typing including DQA1 and DPA1, and allelic resolution typing for HLA class I, the latter one being unique in this field. Evaluation of the high-resolution typing results of the last 19years showed a clear increase in the number of loci tested by the participating laboratories and a clear change of method from Sanger sequencing with additional other techniques (SSO/SSP) to the nowadays widely used next-generation sequencing method. By strictly using the EFI rules for high-resolution HLA typing, the participants were made aware of the ambiguities within exons 2 and 3 for class I and exon 2 for class II and the presence of null alleles even in a two-field HLA typing. There was an impressive learning curve, resulting in >98% correctly typed samples since 2017 and a 100% fulfillment of EFI rules for all laboratories for all loci submitted in the last 2years. Overall, this EPT meets the need of an EPT for high-resolution typing for EFI accreditation.

INDONESIAN PRE-SERVICE ENGLISH TEACHERS’ ATTITUDES TOWARDS THE USE OF WORLD ENGLISHES IN INTERNATIONAL ENGLISH PROFICIENCY TESTS: A SMALL-SCALE SURVEY

While a considerable number of English language users come from expanding-circle countries, international English proficiency tests like TOEFL and IELTS tend to model inner-circle varieties like British, North American, and Australian, implying that inner-circle varieties are more preferable. This quantitative study investigated the attitudes of Indonesian student teachers of English towards the use of World Englishes (WE) in international English proficiency tests like TOEFL and IELTS. 86 student teachers from the same cohort at a private university in Indonesia were involved. The data were collected using an 18-item questionnaire adopted from Monfared (2020) and then analyzed statistically using SPSS. The results of this study indicated that the participants generally acknowledged the idea of the use of World Englishes in international English proficiency tests, but they tended to disapprove deviations from standard English grammar and vocabulary. The implications of this study are also discussed.

Evaluation of HMF levels in unbranded flower honeys in terms of food safety

5-hydroxymethylfurfural (HMF) is formed by reducing sugars in honey in acidic environments by the Maillard reaction and is known as a carcinogenic, mutagenic and genotoxic compound. The aim of this study is to investigate the toxic HMF content of unbranded flower honey samples sold under the sun under inappropriate conditions and unsupervised on the highway sides and to make an evaluation in terms of food safety. The quality of the analysis results was guaranteed by participating in an international proficiency test. Analysis was performed on a High-Performance Liquid Chromatography (HPLC) device with Diode Array Detector (DAD) and Refractive Index (RI) detectors- The HMF levels of 5 honey samples were determined to exceed the legal limit (40 mg kg-1). It is revealed by the current study that the honey sold on the roadside is not safe in terms of toxic HMF. In addition, 5 samples were not found to comply with the regulation in terms of glucose + fructose content and 2 samples in terms of fructose/glucose ratio. Thus, it has also been determined that these honeys are not reliable in terms of purity.

Method of Glyphosate, AMPA, and Glufosinate Ammonium Determination in Beebread by Liquid Chromatography-Tandem Mass Spectrometry after Molecularly Imprinted Solid-Phase Extraction.

The aim of this study was to develop a method for the determination of glyphosate, its metabolite aminomethylphosphonic acid (AMPA), and glufosinate ammonium residues in beebread samples, which could then be used to assess bees’ exposure to their residues. The complexity of beebread’s matrix, combined with the specific properties of glyphosate itself, required careful selection and optimization of each analysis step. The use of molecularly imprinted solid-phase extraction (MIP-SPE) by AFFINIMIP glyphosate as an initial clean-up step significantly eliminated matrix components and ensured an efficient derivatization step. Colorless beebread extracts were derivatized by the addition of 9-fluorenylmethyl chloroformate (FMOC-Cl). After derivatization, in order to remove FMOC-OH and residual borate buffer, a solid-phase extraction (SPE) clean-up step using Oasis HLB was carried out. Instrumental analysis was performed by liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS). The method was validated according to the SANTE/11312/2021 guideline at concentrations of 5, 10, and 100 µg/kg, and satisfactory recovery (trueness) values (76–111%) and precision (RSDr) ≤ 18% were obtained. The limit of quantification (LOQ) was 5 µg/kg for AMPA and glufosinate ammonium and 10 µg/kg for glyphosate. The method was positively verified by the international proficiency test. Analysis of beebread samples showed the method’s usefulness in practice. The developed method could be a reliable tool for the assessment of beebread’s contamination with residues of glyphosate, its metabolite AMPA, and glufosinate ammonium.

An ultra-sensitive UHPLC-QqQ-MS/MS method for determination of 54 benzodiazepines (pharmaceutical drugs, NPS and metabolites) and z-drugs in biological samples

Benzodiazepines exhibit central nervous system depressive activity as well as sedative, hypnotic, and anticonvulsant properties, which enable to use them as medical treatment in anxiety, epilepsy, insomnia and alcohol withdrawal syndrome. However, from 2000s illegal benzodiazepine derivatives have started to emerge on illicit drug market as new psychoactive substances (NPSs) monitored in many countries.Analysis of both pharmaceutical drugs and NPSs from benzodiazepines group could be challenging, as usually very low concentrations need to be determined. Thus, an ultra-sensitive UHPLC-QqQ-MS/MS method was developed for simultaneous determination of 54 benzodiazepines (pharmaceutical drugs, NPS and their metabolites) and 3 z-drugs with one metabolite in biological fluid samples. The lower limit of quantification for most substances was 50 pg/mL, whereas for 17 substances as low as 10 pg/mL was achieved. Together with reduced sample volume to 100 μL it makes the developed method suitable for a sensitive multidrug toxicological analysis. Presented method was applied in routine toxicological practice as well as for the determination of benzodiazepines, z-drugs and their metabolites in 25 authentic biological fluids (blood, urine, vitreous humor and bile), both antemortem and postmortem. 19 different compounds, including benzodiazepines, their metabolites and z-drugs were determined. Antemortem blood concentrations were within 0.2–114.5 ng/mL, whereas concentrations in antemortem urine samples were 0.03–102.6 ng/mL. In postmortem specimens, concentrations ranged within 0.2–473.2 ng/mL, 0.5–94.1 ng/mL, 1.3–208.8 ng/mL and 41.5–42.0 ng/mL in blood, vitreous humor, urine and bile, respectively.The developed method is suitable for a forensic toxicology analysis, as well as clinical toxicology which is evidenced by the positive results of international proficiency tests.

Validated single urinary assay designed for exposomic multi-class biomarkers of common environmental exposures.

Epidemiological studies often call for analytical methods that use a small biospecimen volume to quantify trace level exposures to environmental chemical mixtures. Currently, as many as 150 polar metabolites of environmental chemicals have been found in urine. Therefore, we developed a multi-class method for quantitation of biomarkers in urine. A single sample preparation followed by three LC injections was optimized in a proof-of-approach for a multi-class method. The assay was validated to quantify 50 biomarkers of exposure in urine, belonging to 7 chemical classes and 16 sub-classes. The classes represent metabolites of 12 personal care and consumer product chemicals (PCPs), 5 polycyclic aromatic hydrocarbons (PAHs), 5 organophosphate flame retardants (OPFRs), 18 pesticides, 5 volatile organic compounds (VOCs), 4 tobacco alkaloids, and 1 drug of abuse. Human urine (0.2 mL) was spiked with isotope-labeled internal standards, enzymatically deconjugated, extracted by solid-phase extraction, and analyzed using high-performance liquid chromatography-tandem mass spectrometry. The methanol eluate from the cleanup was split in half and the first half analyzed for PCPs, PAH, and OPFR on a Betasil C18 column; and pesticides and VOC on a Hypersil Gold AQ column. The second half was analyzed for tobacco smoke metabolites and a drug of abuse on a Synergi Polar RP column. Limits of detection ranged from 0.01 to 1.0 ng/mL of urine, with the majority ≤0.5 ng/mL (42/50). Analytical precision, estimated as relative standard deviation of intra- and inter-batch uncertainty, variabilities, was <20%. Extraction recoveries ranged from 83 to 109%. Results from the optimized multi-class method were qualified in formal international proficiency testing programs. Further method customization options were explored and method expansion was demonstrated by inclusion of up to 101 analytes of endo- and exogenous chemicals. This exposome-scale assay is being used for population studies with savings of assay costs and biospecimens, providing both quantitative results and the discovery of unexpected exposures.

Aligning Language Test Scores to Local Proficiency Levels: The Case of China’s Standards of English Language Ability (CSE)

The past decade has seen an emerging interest in aligning test scores to language proficiency levels of external performance scales or frameworks, such as the Common European Framework of Reference (CEFR). Such alignment is ultimately a claim about the interpretation of test scores in relation to external levels of language proficiency. To support such a claim, established procedures should be carefully implemented and documented, and multiple sources of evidence should be collected. This paper demonstrates the steps in building an argument for aligning the scores of an international English language proficiency test to the levels of China’s Standards of English Language Ability, or CSE, a localized language proficiency framework for English as a foreign language. Aligning an international examination to a localized framework serves to make the test score more relevant to the intended context of its use. We discuss the contextual issues that should be considered when interpreting test scores in relation to local proficiency levels, given the potential impact of score-based decisions on individuals and institutions. The implications for similar alignment research will also be presented.

The Influence of Cognitive, Affective, and Sociocultural Individual Differences on L2 Chinese Speech Performance: A Multiple Indicators Multiple Causes Approach.

Informed by Segalowitz's (Cognitive bases of second language fluency, Routledge, 2010) L2 speech production model and MacIntyre et al.'s (Mod Lang J 82(4):545-562, 1998. https://doi.org/10.1111/j.1540-4781.1998.tb05543.x ) L2 willingness to communicate model, this study sought to understand the influence of cognitive, affective and sociocultural individual differences on advanced learners' L2 Chinese speech performance. A total of 240 advanced L2 Chinese learners in China participated in the study. The participants' perceptions of the impact of cognitive, affective, and sociocultural factors on their L2 Chinese speech performance were measured by an adapted questionnaire. A speaking test, following the Hanyu Shuiping Kouyu Kaoshi (HSKK, an international standardized L2 Chinese speaking proficiency test for non-native speakers), was employed to evaluate the participants' L2 Chinese speech performance. The results of multiple indicators multiple causes (MIMIC) analysis show that (1) cognitive factors such as cognitive fluency, expression practice strategy, and assistance strategy, (2) affective factors such as speaking self-efficacy, speaking anxiety, and speaking motivation, and (3) sociocultural factors such as attitudes toward target language class and attitudes toward target language culture jointly influence advanced L2 Chinese learners' speech performance. Results and implications of the present study are discussed for enhancinglearners' L2 Chinese speech performance.

Zsírban oldódó A-, D2-, D3-, E- és K3-vitaminok meghatározása izotóphígítással és LC-MS/MS műszeregyüttessel

The purpose of our publication is the determination of the total amount (of natural origin and added) of fat-soluble vitamins A, D2, D3 and E in low amounts in foods (wheat flour, soft drinks, effervescent tablets) and dietary supplements using a liquid chromatography tandem mass spectrometry (LC-MS/MS) method. The samples were diluted with isotope-labeled derivatives of the target components (vitamin A-d6, vitamin D2-d3, vitamin D3-d3, vitamin E-d6), and after extraction and saponification, they were purified by liquid-liquid extraction. After a solvent exchange, the concentration of the vitamins was determined on a C8 HPLC column using acidic mobile phases (0.1% formic acid in water/methanol) and LC-MS/MS technique. In dietary supplements, the analysis of the fat-soluble vitamin K3 may also be important, because the use of vitamin K3 is currently not approved in human formulations. During the determination of vitamin K3, saponification is not necessary, due to its structure, alkaline hydrolysis would lead to the decomposition of vitamin K3, so this component was analyzed by a method different from the one used for the other vitamins. LC-MS/MS analysis of small amounts of vitamin K3 is more complicated than that of other vitamins due to the low sensitivity of the MS instrument to vitamin K3. The determination of vitamin K3 was therefore carried out after chemical derivatization with L-cysteine as a derivatizing reagent, also with isotope dilution and LC-MS/MS technique. After intralaboratory validation, the methods were successfully used in domestic and international proficiency tests in infant formulas and liquid vitamin preparations.

A Preliminary Study to Determine the Hydrogen and Oxygen Isotopic Compositions of Natural and Bottled Water using High Sensitivity Isotope Ratio Mass Spectrometry

In this study, we introduce the stable isotopic results of water using a recently installed high sensitivity isotope ratio mass spectrometry (HS-IRMS) system at the Korea Institute of Geoscience and Mineral Resources (KIGAM). As a result of analytical method validation through an international proficiency test, the 2020 WICO (Water Isotope Inter-Comparison), organized by the International Atomic Energy Agency, the KIGAM IRMS laboratory showed satisfactory performance. Furthermore, stable isotopic compositions of bottled water samples from South Korea were measured using the HS-IRMS with a high temperature conversion elemental analyzer, and this method was re-validated and confirmed by a comparison with stable isotope results obtained using an equilibrium method.

Perspectives of Test Examiners of the Localized Speaking Assessment Framework: A Case Study in Vietnam

The present study explores the test examiners'' perspectives on the role and qualitative aspects of the current localized speaking assessment framework used in Vietnam. A case study with two experienced test examiner-cum-English lecturers was conducted. Inductive content analysis was used to analyze the qualitative data findings obtained from individual semi-structured interviews. Drawbacks, merits, and standardization issues of the current localized speaking assessment frameworks, i.e., the Vietnamese Standardized Test of English Proficiency (VSTEP), were also discussed, especially in comparison to internationally recognized examinations and frameworks such as the International English Language Testing System (IELTS) and the Certificate in Advanced English (CAE) as well as the Common European Framework of Reference for Languages (CEFR). The study informed both English educators and policymakers to improve localized speaking assessment to suit the local teaching needs while still meeting the requirements of widely accepted international proficiency tests.

Analysis of Polycyclic Aromatic Hydrocarbon in Airborne Particulate Matter Samples by Gas Chromatography in Combination with Tandem Mass Spectrometry (GC-MS/MS).

Polycyclic aromatic hydrocarbons (PAHs), the family of organic contaminations, have been shown to have negative effects on human health. However, until now, the comprehension on occurrence, distribution, and risk assessment of human exposure to PAHs has been limited in Vietnam. In this work, a capillary gas chromatography coupled with electron impact ionization tandem mass spectrometry (GC-EI-MS/MS) has been introduced for analysis of 16 PAHs in some particulate matter samples. PAHs have been separated on the TG 5 ms capillary gas chromatographic column and detected by tandem mass spectrometry in multiple reaction monitoring mode. The PAHs in the particulate matter (PM 2.5 and PM 10) samples were extracted by ultrasonic-assisted liquid extraction and cleaned up by an acidic silica gel solid phase extraction. The linearity range of all analyzed PAHs was from 5 to 2000 ng mL−1 with R2 ≥0.9990. Limit of detection (LOD) of PAHs in particulate matter sample was from 0.001 ng m−3 (Br-Naph) to 0.276 ng m−3 (Fln). The recovery of PAHs was investigated by international proficiency testing samples. The recoveries of PAHs in proficiency testing sample ranged from 79.3% (Chr) to 109.8% (IcdP). The in-house validated GC-EI-MS/MS method was then applied to analysis of some particulate matter samples that were collected in the Hanoi areas. The total concentrations of PAHs in several brands of samples collected from Hanoi were found in the range of 226.3 ng m−3–706.43 ng m−3. Among the studied compounds, naphthalene was found at high frequency and ranged from 106.5 ng m−3 to 631.1 ng m−3. The main distribution of the PAHs in particulate matter samples was two-ring and three-ring compounds.

Volatile organic compounds from building products—Results from six round robin tests with emission test chambers conducted between 2008 and 2018

Emission testing of volatile organic compounds (VOC) from materials and products is commonly based on emission test chamber measurements. To ensure the comparability of results from different testing laboratories, their measurement performance must be verified. For this purpose, Bundesanstalt für Materialforschung und -prüfung (BAM) organizes an international proficiency test (round robin test, RRT) every two years using well-characterized test materials (one sealant, one furniture board, and four times a lacquer) with defined VOC emissions. The materials fulfilled the requirements of homogeneity, reproducibility, and stability. Altogether, 36 VOCs were included of which 33 gave test chamber air concentrations between 13 and 83µg/m3 . This is the typical concentration range to be expected and to be quantified when performing chamber tests. Three compounds had higher concentrations between 326 and 1105µg/m3 . In this paper, the relative standard deviations (RSD) of BAM round robin tests since 2008 are compared and the improvement of the comparability of the emission chamber testing is shown by the decrease of the mean RSD down to 28% in 2018. In contrast, the first large European interlaboratory comparison in 1999 showed a mean RSD of 51%.