Search Results (31)

Dietary supplements containing red yeast rice (RYR), a fermentation product of the fungus Monascus purpureus grown on white rice, remain popular in Europe as proclaimed cholesterol-lowering aids. The cholesterol-lowering effects are due to the occurrence of monacolin K, which is often present as a mixture of monacolin K lactone (MK) and as monacolin K hydroxy acid (MKA). MK is structurally similar to the cholesterol-lowering medicine lovastatin. Recently, due to safety concerns linked to the use of statins, the European Commission prohibited RYR supplements with a maximum serving exceeding 3 mg of total monacolins per day. Moreover, the amount of the mycotoxin citrinin, potentially produced by M. purpureus, was also reduced to 100 µg/kg. Evidently, manufacturers that offer their products on the European market, including the online market, must also be compliant with these limits in order to guarantee the safety of their products. Therefore, thirty-five different RYR supplements, purchased from an EU-bound e-commerce platform or from registered online pharmacies, were screened for their compliance to the European legislation for citrinin content and the amount of total monacolin K. This was conducted by means of a newly developed LC-MS/MS methodology that was validated according to ISO 17025. Moreover, these supplements were also screened for possible adulteration and any contamination by micro-organisms and/or mycotoxins. It was found that at least four of the thirty-five RYR supplements (≈11%) might have reason for concern for the safety of the consumer either due to high total monacolin K concentrations exceeding the European predefined limits for total monacolins or severe bacterial contamination. Moreover, three samples (≈9%) were likely adulterated, and the labeling of six of the seventeen samples (≈35%) originating from an EU-based e-commerce platform was not compliant, as either the mandatory warning was missing or incomplete or the total amount of monacolins was not mentioned. Full article

The quantification of human DNA extracts from forensic samples plays a key role in the forensic genetics process, ensuring maximum efficiency and avoiding repeated analyses, over-amplified samples, or unnecessary examinations. In our laboratory, we use the Quantifiler^® Trio system to quantify DNA extracts from a wide range of samples extracted from traces (bloodstains, saliva, semen, tissues, etc.), including swabs from touched objects, which are very numerous in the forensic context. This method has been extensively used continuously for nine years, following an initial validation process, and is part of the ISO/IEC 17025 accredited method. In routine practice, based on the quantitative values determined from the extracts of each trace, we use a standard method or a low-copy-number method that involves repeating the amplification with the generation of a consensus genetic profile. Nowadays, when the quantification results are less than 0.003 ng/μL in the minimum extraction volume (40 μL), we do not proceed with the DNA extract analysis. By verifying the limits of the method, we make a conscious cost-benefit choice, in particular by using the least amount of DNA needed to obtain sufficiently robust genetic profiles appropriate for submission to the Italian DNA Forensic Database. In this work, we present a critical re-evaluation of this phase of the method, which is based on the use of standard curves obtained from the average values of the control DNA analysed in duplicate. Considering the various contributions to uncertainty that are difficult to measure, such as manual pipetting or analytical phases carried out by different operators, we have decided to thoroughly investigate the contribution of variability in the preparation of calibration curves to the final results. Thus, 757 samples from 20 independent experiments were re-evaluated using two different standards for the construction of curves, determining the quantitative differences between the two methods. The experiments also determined the parameters of the slope, Y-intercept, R², and the values of the synthetic control probe to verify how these parameters can provide information on the final outcome of each analysis. The outcome of this revalidation demonstrated that it is preferable to use quantification ranges rather than exact quantitative limits before deciding how to analyse the extracts via PCR or forgoing the determination of profiles. Additionally, we present some preliminary data related to the analysis of samples that would not have been analysed based on the initial validation, from which genetic profiles were obtained after applying a concentration method to the extracts. Our goal is to improve the accredited analytical method, with a careful risk assessment as indicated by accreditation standards, ensuring that no source of evidence is lost in the reconstruction of a criminal event. Full article

Paralytic shellfish poisoning is an important concern for mollusk fisheries, aquaculture, and public health. In Galicia, NW Iberian Peninsula, such toxicity has been monitored for a long time using mouse bioassay. Therefore, little information exists about the precise toxin analogues and their possible transformations in diverse mollusk species and environments. After the change in the European PSP reference method, a refinement of the Lawrence method was developed, achieving a 75% reduction in chromatogram run time. Since the beginning of 2021, when this refinement Lawrence method was accredited under the norm UNE-EN ISO/IEC 17025, it has been used in the area to determine the toxin profiles and to estimate PSP toxicity in more than 4500 samples. In this study, we have summarized three years of monitoring results, including interspecific, seasonal, and geographical variability of PSP toxicity and toxin profile. PSP was detected in more than half of the samples analyzed (55%), but only 4.4% of the determinations were above the EU regulatory limit. GTX1,4 was the pair of STX analogs that produced the highest toxicities, but GTX2,3 was found in most samples, mainly due to the reduction of GTX1,4 but also by the higher sensitivity of the method for this pair of analogs. STX seems to be mainly a product of biotransformation from GTX2,3. The studied species (twelve bivalves and one gastropod) accumulated and transformed PSP toxins to a different extent, with most of them showing similar profiles except for Spisula solida and Haliotis tuberculata. Two seasonal peaks of toxicity were found: one in spring-early summer and another in autumn, with slightly different toxin profiles during outbreaks in relation to the toxicity during valleys. In general, both the total toxicity and toxin profiles of the southernmost locations were different from those in the northern part of the Atlantic coast and the Cantabrian Sea, but this general pattern is modified by the PSP history of some specific locations. Full article

The current study presents a non-random, quantitative experimental investigation detailing the steps required to accredit a non-regulated test method (referred to as its own) under the ISO/IEC 17025:2017 standard and the criteria set by the Mexican Accreditation Entity (EMA). The focus is on the methodology employed to validate the test method, particularly emphasizing the precision of the measurement system, along with the total variation in and tolerance of its components. For the measurement analysis, repeatability and reproducibility (r&R) studies were conducted using a variance analysis method variant (ANOVA). This variant is highlighted for its ability to estimate deviations more accurately. Furthermore, the chosen model incorporates random effect measurements for all factors or components of system variation (operators, parts, interaction, and instrument). This approach demonstrates the reliability, accuracy, and precision of the proposed measurement system within the test method, leading to its subsequent accreditation under ISO/IEC 17025:2017 as a conformity assessment body. Full article

A comparison of low-cost radon monitors was conducted at the Laboratory of Natural Radiation (LNR). The monitors we evaluated were EcoQube, RadonEye, RadonEye Plus2, Spirit, ViewPlus, ViewRadon and WavePlus. An AlphaGUARD monitor calibrated at the Laboratory of Environmental Radioactivity of the University of Cantabria (LaRUC), accredited for testing and calibration according to ISO/IEC 17025, provided the reference value of radon concentration. The temporal stability of the monitors was studied, obtaining a percentage of missing records ranged from 1% to 19% of the data. The main technical characteristics studied were temporal stability, measurement ranges, accuracy, correlation and response time. The main results show that the measurement ranges align with those specified by their manufacturers, with percentage differences with respect to the reference monitor of between 5% and 16%. The diversity found for response time is remarkable, with values ranging from 1 to 15 h, with Pearson correlation factors between 0.63 and 0.90. Full article

The increasing demand for sustainable products and services has become a constant requirement for the different stakeholders in an organization. Higher Education Institutions (HEI) have a crucial role in training conscious and competent professionals to lead these changes. Chemical analyses laboratories bring together the proper mix, where the adoption of mature and efficient management systems proves to be crucial not only to better train the institutions’ human resources but also to cooperate in recruiting research projects and other services to benefit society. Maturity models assist in the needed stages for sustainable growth to take place. This paper proposes a maturity model based on standardized norms to guide adjustments related to quality, risks, safety, and environment of chemical analyses laboratories in public higher education institutions. This research was done in four stages: theoretical research about maturity models, sustainability, and integrated management systems; survey with laboratories; case study at a chemical analyses laboratory of an HEI; and structuring and validating a maturity model. As the main results, it was observed that more than 80% of public laboratory managers believe it would be relevant to adopt a maturity model to help organize the laboratory’s internal and external processes. 86% of public laboratory managers understand that using management systems can contribute to hiring new services. We can also observe that 42.9% of public laboratory managers do not know any maturity model. As conclusion, the model includes eight dimensions, 31 subdimensions, and 204 management practices to assess and guide chemical analyses laboratories to sustainable maturity levels. Full article

Mycotoxin contamination of feed and feed materials represent a serious health hazard. This study details the occurrence of aflatoxin B₁ (AFB₁), zearalenone (ZEN) and ochratoxin A (OTA) in 826 feed and 617 feed material samples, collected in two Italian Regions (Umbria and Marche) from 2018 to 2022 analyzed using a UPLC-FLD platform. The developed method was validated and accredited (ISO/IEC 17025) with satisfactory accuracy and precision data obtained in repeatability and intralaboratory reproducibility conditions. Feed had a higher incidence of contaminated samples (26%) with respect to feed materials (6%). AFB₁ was found up to 0.1045 mg/kg in cattle feeds and 0.1234 mg/kg in maize; ZEN was detected up to 6.420 mg/kg in sheep feed while OTA was rarely reported and in lower concentrations (up to 0.085 mg/kg). Co-contamination of at least two mycotoxins was reported in 0.8% of the analyzed samples. The incidence of above maximum content/guidance level samples was 2% for feed and feed materials while almost 3-fold-higher for maize (5.8%) suggesting how mycotoxin contamination can affect some matrices more than others. Obtained data can be useful to improve official monitoring plans and therefore further raise awareness of this issue between agriculture stakeholders, healthcare entities and non-professionals. Full article

Background: The number of periprosthetic joint infections caused by vancomycin-resistant pathogens is increasing. Currently, no PMMA cement is commercially available to cover VRE. Daptomycin shows promising results in treating infection, offering a good safety profile and a reduced risk of developing resistance. The purpose of this in vitro study was to investigate the mechanical stability, handling properties, elution behavior, and antimicrobial effectiveness of PMMA cement loaded with three different daptomycin concentrations in comparison to commercially available antibiotic-loaded bone cement (ALBC). Methods: Mechanical properties and handling characteristics (ISO 5833, DIN 53435), HPLC elution, antimicrobial effectiveness with proliferation assay (DIN 17025), and inhibition zone testing were investigated. Results: All tested daptomycin concentrations met the ISO and DIN standards for mechanical strength. Loading of 40 g of PMMA cement with 0.5 g of daptomycin did not show any antimicrobial effectiveness, in contrast to 1.0 g and 1.5 g. PMMA cement with 1.5 g of daptomycin was the best in terms of elution and effectiveness, and it showed good ISO mechanical strength; ISO doughing was sticky for a little longer and setting was faster compared to the vancomycin-containing reference cement. Conclusion: PMMA cement containing 0.5 g of gentamicin and 1.5 g of daptomycin could be a good alternative to the already established COPAL^® (Wehrheim, Germany) G+V for the treatment of PJIs caused by VRE. Full article

Thermal processing equipment used in the aerospace industry must meet the requirements of the processes for which they are intended. The periodic tests performed by calibration laboratories, according to the AMS2750 specification, are intended to ensure compliance with these equipment requirements. While this specification does not explicitly state the need for uncertainty calculation, it does specify that pyrometry laboratories must have an ISO/IEC 17025 Quality System accredited by a recognized regional body which is a member of the International Laboratory Accreditation Cooperation (ILAC). Therefore, the calculation of uncertainties is necessary. This work presents a methodology for conducting temperature uniformity surveys and uncertainty assessment in these tests. This methodology has been applied to four different types of equipment to analyse, in each case, the contributions of uncertainties and to assess their potential for improvement. The objectives that laboratories should aim for include improving measurement accuracy and reducing uncertainty components in order to meet the criteria of both AMS2750 and ISO/IEC 17025. Full article

Organizations and laboratories tend to integrate systems based on risk management. Risk management helps to optimize laboratory processes and information flow, increase valid and reliable results, and make better decisions. This paper describes the development and present trends in risk management related to standard ISO/IEC 17025. This paper focuses on risk assessment in the accredited testing laboratories using the FMEA tool. In the basic eight defined laboratory areas, risks were identified and evaluated, and methods were proposed to minimize them. Full article

Currently, testing and calibration laboratories are undergoing organizational restructuring in view of technical and regulatory requirements. To assist these laboratories, maturity models (MMs) can be used for the implementation and maintenance of management systems. The use of fuzzy logic is often found in association with the construction of MMs. Fuzzy logic helps in the construction of these models, removing subjective elements from the maturity assessment. Therefore, the objective of this study was to perform a systematic literature review (SLR) using the Methodi Ordinatio focused on MMs built with fuzzy logic that aim to evaluate the degree of maturity of testing and calibration laboratories that have implemented ISO/IEC 17025 for their quality management systems (QMSs). This analysis was performed with articles published between 2012 and 2022 in several databases using keywords such as “maturity model”, “fuzzy” and “ISO 17025” and resulted in 18 articles, which made up the bibliographic portfolio. After analyzing the content of these studies, it was possible to conclude that, although no study specifically discussed this MM, the discovered articles were important for presenting ideas and suggestions for future research. Full article

In this project, a prompt, efficient, and effective method for Cd²⁺ ions extraction from different food and water samples using magnetic dispersion-based solid phase extraction by functionalized iron oxide nanoparticles was proposed. Iron oxide nanoparticles were synthesized through the co-precipitation method followed by functionalization with tetraethyl orthosilicate (TEOS) and 3-aminopropyl silane (APTES) to obtain Fe₃O₄@SiO₂@APTES. This composite was characterized through different techniques, including vibrating sample magnetometer, dynamic light scattering, zeta potential, FTIR, SEM, XRD, and BET. Variables studied were pH, temperature, sorbent amount, sonication time, and sample and eluent volume affecting the sorption efficacy of freshly synthesized sorbent. Plackett–Burman design was utilized for the identification of significant factors for microextraction of target analyte, while the central composite design was utilized for the optimization of significant factors. Detection and quantification limits obtained were 0.17 and 0.58 μgL⁻¹, respectively, with an enhancement factor of 83.5. Under optimum conditions, Fe₃O₄@SiO₂@APTES showed good stability even after >80 adsorption/desorption cycles run while maintaining over 96% analyte recoveries. The developed method was validated by assessing certified reference materials and standard addition methodology for Cd²⁺ detection in real samples. To confirm the precision, repeatability (RSD_r) and reproducibility (RSD_R) were calculated and found as <3.0 (n = 7) and <7.5 (n = 15), respectively. Furthermore, in accordance with the ISO/IEC 17025 recommendations, the validation was also confirmed through a “bottom-up” approach while considering all possible uncertainties in data. Full article

Peanut allergy is a lifelong, increasingly prevalent, and potentially life-threatening disease burdening families and communities. Dietary, particularly polyunsaturated fatty acids (PUFAs), intakes can exert positive effects on immune and inflammatory responses, and the red blood cell (RBC) membrane lipidome contains stabilized metabolic and nutritional information connected with such responses. The fatty-acid-based membrane lipidome profile has been exploratorily evaluated in a small cohort of patients (eight males and one female, age range 4.1–21.7 years old, body mass index BMI < 25) with angioedema and/or anaphylaxis after peanut ingestion. This analysis was performed according to an ISO 17025 certified robotic protocol, isolating mature RBCs, extracting membrane lipids, and transforming them to fatty acid methyl esters for gas chromatography recognition and quantification. Comparison with a group of age- and BMI-matched healthy individuals and with benchmark interval values of a healthy population evidenced significant differences, such as higher levels of ω-6 (arachidonic acid), lower values of ω-3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), together with an increased ω-6/ω-3 ratio in allergic patients. A significant inverse correlation was also found between specific immunoglobulin E (IgE) levels and ω-6 di-homo-gamma-linolenic acid (DGLA) and total PUFAs. Results of this preliminary study encourage screenings in larger cohorts, also in view of precision nutrition and nutraceuticals strategies, and stimulate interest to expand basic and applied research for unveiling molecular mechanisms that are still missing and individuating treatments in chronic allergic disorders. Full article

Overall, laboratory water quality analysis must have stability in their results, especially in laboratories accredited by ISO 17025. Accredited parameters should be strictly reliable. Using control charts to ascertain divergences between results is thus very useful. The present work applied a methodology of analysis of results through control charts to accurately monitor the results for a wastewater treatment plant. The parameters analyzed were pH, BOD₅, COD, total suspended solids, and total phosphorus. The stability of the results was analyzed from the control charts and 30 analyses performed in the last 12 months. From the results, it was possible to observe whether the results are stable, according to the rehabilitation factor that cannot exceed WN = 1.00 and the efficiency of removal of pollutants that remained above 70% for all parameters. The method of determining the technological reliability and stability of the treatment station using control charts is an efficient tool for detecting any instability in the results. These results help to monitor the results of the analyses more clearly and thus enable a rapid response to possible disturbances and maintain the quality of the analysis control, as well as determining the accreditation entities. Full article

This article presents the results of an LMM-R-2019 interlaboratory comparison. Such comparisons of different families of measuring instruments are one of the activities conducted among the calibration laboratories to maintain their ISO 17025 accreditation. Given that the study of surface roughness is becoming increasingly important in the field of dimensional metrology, the comparison focused on determining the Ra parameter on a pseudorandom metallic roughness standard using two types of measuring instruments: physical contact (stylus instruments) and optical (confocal microscopes). Among the aspects studied was whether the roughness measurements obtained using calibrated confocal microscopes could be compared with those using traditional methods since optical instruments obtain measurements more quickly and responsively than do stylus instruments. The results showed that roughness measurements using confocal microscopes are comparable with those from a traditional stylus instrument. Full article