Preparation Of Reference Materials Research Articles

Separation of full, empty, and partial adeno-associated virus capsids via anion-exchange chromatography with continuous recycling and accumulation

The field of recombinant adeno-associated virus (rAAV) gene therapy has attracted increasing attention over decades. Within the ongoing challenges of rAAV manufacturing, the co-production of impurities, such as empty and partial capsids containing no or truncated transgenes, poses a significant challenge. Due to their potential impact on drug efficacy and clinical safety, it is imperative to conduct comprehensive monitoring and characterization of these impurities prior to the release of the final gene therapy product. Nevertheless, existing analytical techniques encounter notable limitations, encompassing low throughput, long turnaround times, high sample consumption, and/or complicated data analysis. Chromatography-based analytical methods are recognized for their current Good Manufacturing Practice (cGMP) alignment, high repeatability, reproducibility, low limit of detection, and rapid turnaround times. Despite these advantages, current anion exchange high pressure liquid chromatography (AEX-HPLC) methods struggle with baseline separation of partial capsids from full and empty capsids, resulting in inaccurate full-to-empty capsid ratio, as partial capsids are obscured within peaks corresponding to empty and full capsids. In this study, we present a unique analytical AEX method designed to characterize not only empty and full capsids but also partial capsids. This method utilizes continuous N-Rich chromatography with recycling between two identical AEX columns for the accumulation and isolation of partial capsids. The development process is comprehensively discussed, covering the preparation of reference materials representing full (rAAV-LacZ), partial (rAAV-GFP), and empty (rAAV-empty) capsids, N-rich method development, fraction analysis, determination of fluorescence response factors between capsid variants, and validation through comparison with other comparative techniques.

Sociology as a Basis for Curriculum Development for Islamic Religious Education

The purpose of this article is to explain how sociological foundations are the basis for developing the Islamic religious education curriculum. This article uses qualitative research methods, data collection techniques using library research. Library research includes four stages: preparing necessary documents, preparing reference materials, managing time, reading and recording research materials. The results of sociological research are the basis for developing an Islamic religious education curriculum with a focus on introducing culture and the rules of science and technology by maximizing technological developments in learning activities. The world of Islamic religious education experiences a number of significant shifts periodically; Therefore, to compensate for this shift, it is necessary to develop an appropriate curriculum that is supported by a solid foundation. The direction of development goals is understood to ensure that appropriate principles must be applied when designing the Islamic religious education curriculum. The application of sociology in curriculum development contributes to the theoretical and practical development of the Islamic religious education curriculum and can increase authority in decision making regarding Islamic religious education regarding the Islamic religious education curriculum.

50 Years of uranium isotopic reference materials at JRC-Geel

The history of uranium isotopic reference materials from JRC-Geel during the last 50 years is reviewed by presenting certification methods and relevant applications. The certified isotope ratios are traceable to the SI via gravimetrical preparation, either directly through gravimetrical mixing of highly enriched materials, or indirectly using existing gravimetrically prepared reference materials for calibration of mass spectrometers used for certification measurements. Due to developments of mass spectrometers and analytical methods, certification measurements have improved regarding precision, uncertainties and accuracy. This has led to a comprehensive set of uranium isotopic reference materials available for nuclear safety, security and the scientific community.

Preparation of Reference Material for Component Analysis of High Silica Glass Fiber

A reference material used for the component analysis of high silica glass fiber is prepared by the high-temperature melting process, a technique that can ensure the homogeneity and stability of each component. With two methods based on different principles, the components in glass fiber are accurately characterized through the joint efforts of multiple laboratories. The results show that the reference material was accurately and reliably characterized and exhibited good homogeneity and stability, and that the expanded uncertainty of the standard values was 5%-10% (k=2). Therefore, the reference material can be used to evaluate component testing methods for high silica glass fiber and calibrate related analytical instruments so that the accuracy and reliability of component characterization are ensured.

Comparison of synthetic zircon, high-temperature and high-pressure sintered zircon and fast hot-pressing sintered zircon for in situ hafnium isotope analysis by LA-MC-ICP-MS

Three zircon synthesis techniques (synthesis, high-temperature and high-pressure sintering and fast hot-pressing sintering) for the preparation of reference materials for Hf isotope analysis of zircon by LA-MC-ICP-MS were compared.

Review Article: Analysis Caffeine in Powder Coffee Using Spectrophotometry UV-VIS Method

Introduction: Caffeine is made by extraction from roasted and ground coffee by dichloromethane after being heated in deionized water mixed with magnesium oxide. The extract was purified, dried and bottled in a bottle of dark glass. A stratified random selection was applied to select a number of vials for the study of homogeneity and stability, which revealed that the prepared reference material was homogeneous and fairly stable. Objective: This study aims to determine the level of caffeine levels in ground coffee. The quantification of the % purity of caffeine was performed using a calibrated UV/visible UV/visible spectrophotometer and high-performance liquid chromatography calibrated by the diode-array detection method. Method: This study uses literature review, from several articles published in literature through PubMed, Science Direct, Researchgate, publons and Google Scholar with articles published from 2012 to 2022. Result and Discussion: The results obtained from both methods combined to drive the certified value and uncertainty regarding the certified value of the purity of the reference material were found to be 99.86% and the associated uncertainty was ±0.65%, which makes the candidate reference material a very useful calibran in the chemical analysis of food and medicine. Conclusion: It can be concluded that the caffeine levels contained in robusta and arabica coffee beans with varying soaking duration of 3 days, 5 days, and 7 days there are differences in caffeine levels

Preparation of in-house reference material of Fe, Ca, Ni and Si in carbon sample from an aluminum industry and results of a proficiency test

This work presents the preparation of a reference material for Fe, Ca, Ni and Si in order to ensure the quality of the analysis of these elements in routine samples of carbonaceous materials in a aluminum industry. The sample was fractioned and bottled for homogeneity and stability studies before being shipped to interlaboratory certification. Then, we sent a bottle for each one of seven participating laboratories to define the reference values. The results of concentration for Fe, Ca, Ni and Si, after outlier exclusion were 589.1 ± 25.3, 142.9 ± 12.0, 178.1 ± 9.3 and 134.2 ± 6.6, respectively. Finally, we applied the technique of z-score, to evaluate the performance of the participating laboratories. After the results of this study we can conclude that the carbon material can be used like reference material for in-house control of Fe, Ca, Ni and Si analyses.

Analysis on the Quality Status of in Vitro Diagnostic Reagents for National Medical Device Supervision and Inspection in 2020

This paper puts forward suggestions on the development of in vitro diagnostic reagents and supervision measures for the post-marketing products, so as to further improve the quality of in vitro diagnostic reagents and ensure the safety use of medical device. This paper summarizes the quality of in vitro diagnostic reagents and analyzes the causes of the problems, according to the results of the national medical device supervision and inspection in 2020. The overall quality of in vitro diagnostic reagents for national medical device supervision and inspection in 2020 is stable and the unqualified detection rate is 1.6%. However, there are some problems. For example, the management of raw materials is unscientific, the faultiness in the preparation of reference materials, the understanding of standards is unthorough, and the management of instructions is unimportance. It is suggested that manufacturers of in vitro diagnostic reagents should improve the binding force of the quality management system, strengthen the awareness of risk management, attach importance to communicate with regulatory authorities, study standards sufficiently and strengthen the management of instructions. It is also suggested that the regulatory authorities should strengthen supervision and inspection, and further complete the evaluation guidance and standard publicity and implementation.

Methodology for preparing a reference sample in the air filter matrix

The proficiency tests are widely used to evaluate the analytical capacity of laboratories and also as part of the accreditation processes. The National Intercomparison Program is a Proficiency Test that uses radioactive reference materials in soil, vegetation, water and air filters. This work is a study of the choice of composition of radionuclides ideal to be used in the air filters to be produced by LNMRI as reference material for PNI. 
 Five cocktails composed of different radionuclides chosen for their energies in the range of 30 to 2000 keV were prepared, each cocktail was distributed in three glass fiber air filters using a pantograph using the pycnometer technique, contaminating each filter with 19 (nineteen) drops, totaling fifteen (15) air filter samples, with the objective of homogeneous distribution of the droplets at the sites determined by the geometry chosen without the need for marking in the filters, in order to choose the best composition to be used in the preparation of reference material.

Feed reference materials in the system of metrological support of agro-industrial complex laboratories

The authors provided information about the developed matrix feed reference materials, certified for quality, nutritional value and toxicological contamination indicators for metrological support of analytical work in the article to confirm the compliance of products with requirements of national standards. Information on the stages of development of feed reference materials (selection and preparation of reference material, studies of heterogeneity and stability of feed reference material) is presented. There are demonstrated the results of reference materials certification according to certified indicators, their correctness confirmed by the results of thirty accredited laboratories.The developed reference material of sunflower meal is registered in the State Register of approved types of reference materials under the number GSO 11612-2020. Reference materials of the composition of toasted soybean feed meal and complete feed for poultry (broilers) are approved as Industry-Specific by the Ministry of Agriculture of the Russian Federation (Department of Plant Production, Mechanization, Chemicalization and Plant Protection).Feed reference materials are intended for metrological support of agro-industrial complex laboratories.

Application of the lyophilization system for preparation of reference materials for composition of nutrition products

The article presents the application of the lyophilization system for preparation of reference materials (RM) for composition of nutritive products samples. The purpose of the research was the development of lyophilization procedure of RM for composition of poultry meat samples preparation with certified values of mass fraction of moisture, nitrogen (protein) and fat.The poultry meat of two types was used as the primary material for RM for poultry meat composition preparation -1) white meat (chicken breast); 2) red meat (chicken thigh). The procedure included pounding, boiling, freezing and lyophilisation (syn. freeze drying). The researches for homogeneity were implemented with hot air dryer standard system from the State primary standard GET 173-2017. Measurement of nitrogen (protein) mass fraction was performed on State secondary standard GVET176-1-2010. Measurements of fat mass fraction were performed with accordance to State Primary Reference Measurement Procedure.The total time of lyophilization process for samples № 1 and № 2 was 19 and 28 hours, respectively. The total mass loss for sample № 1 was about 63 %, for sample № 2 was about 65 %. The difference in material moisture mass fraction values of materials dried on different trays of freeze dryer was statistically significant, i. e., material was non-homogeneous. To obtain a homogeneous material, an additional homogenization procedure was performed: grinding in a laboratory mill, sieving through a sieve, thorough mixing and conditioning. The certified values of moisture, nitrogen, protein, fat mass fraction for the sample № 1 were accordingly 4,5 %, 14,74 %, 92,1 %, 7,9 %. The same values in the same sequence were 6,3 %, 12,21 %, 76,3 %, 23,8 %.The procedure of lyophilisation was developed for production of reference materials for composition of boiled and freeze-dried poultry meat. The usage of this lyophilisation system allowed to ensure a RM expiration date of six months at ambient temperature of (7±3) °C and relative humidity no more than 60 %. The Reference Materials for composition of boiled and freeze-dried poultry meat was added into Register of certified RMs under № GSO 11276-2019 by the results.

Characterisation of ciguatoxins

The primary objective of this specific grant was to characterize the risk associated to Ciguatera Poisoning (CP) in the EU by developing a sensitive methodology of LC-MS/MS. The preparation of reference materials including the main ciguatoxins (CTXs) responsible for the contamination was considered the secondary objective to facilitate the implementation of the LC-MS/MS methods in the EU laboratories to characterize this emerging risk. C-CTX1 has been identified by LC-MS/MS, and further confirmed by LC-HRMS, as the main responsible for the CTX toxicity in the samples from the areas selected for this study. The low concentrations levels of CTXs found on the samples evaluated has been a key limitation for the completion of the objectives of this specific grant (SG), being necessary to establish contingency plans, not only to overcome the problems of sensitivity that might compromise the confirmation of the toxic profiles, but also to accomplish the task of preparing reference materials. The contingency plans involved the development of two complementary LC-MS/MS approaches, as well as a methodological approach combiningLC-MS/MS, Neuroblastoma cell assay and chromatographic fractionations (HPLC and GPC) to characterize the toxins present in the contaminated extracts. This approach has been also used for the preparation of reference materials in order to confirm the presence of the C-CTX1 in both pure solutions of C-CTX1 and Fish Tissue Reference materials (FTRM) containing C-CTX1. The LC-MS/MS analysis of Dinoflagellates samples (Gambierdiscus and Fukuyoa sp) allowed to confirm the lack of correlation between the CTXs contamination and the fish samples from the areas were these dinoflagellates were collected. In these samples, the toxicity was attributed to several Maitotoxins analogues as well as gambieric acids C and D, Gambierone, 44-methyl gambierone, and gambieroxide that were identified by LC-HRMS with varying degrees of confirmation in strains of Gambierdiscus and Fukuyoa from the Mediterranean Sea and North East Atlantic Ocean.

Simultaneous determination of eight additives in polyethylene food contact materials by ultrahigh-performance liquid chromatography

食品接触材料中添加剂残留量的测定为食品接触材料从源头进行安全监管具有重要意义。然而目前的大多数研究只针对食品接触材料中有害物迁移量的测定,对于食品接触材料中有害物含量的测定方法仅局限于残留单体、低聚体、重金属,以及邻苯二甲酸酯类、双酚类化合物等环境污染物,对食品接触材料中添加剂残留量的测定较少。该研究系统地优化了样品前处理过程及仪器分析中影响8种添加剂分析准确度与响应灵敏度的各主要因素,建立了超高效液相色谱同时测定聚乙烯材料中8种添加剂的定量分析方法。聚乙烯样品冷冻研磨后,取2.0 g样品采用甲苯作为萃取溶剂,80 ℃, 10.34~11.72 MPa (1500~1700 psi)下对其进行加速溶剂萃取,取10 mL上清液,氮气吹干后用10 mL初始流动相(甲醇-水,7∶3, v/v)定容。采用ACQUITY UPLC BEH C8色谱柱(100 mm×2.1 mm, 1.7 μm)进行分离,柱温30 ℃,进样量5 μL,以乙腈和水作为流动相进行梯度洗脱,流速0.3 mL/min,二极管阵列检测器(DAD)在210~400 nm范围内扫描,230、250、280、330 nm监测,外标法定量。8种目标物在0.2~10 μg/mL质量浓度范围内线性关系良好,相关系数(R 2)>0.999。空白聚乙烯样品添加含量为0.05%时,加标回收率在83.8%~103.4%之间,RSD在0.14%~7.86%之间。对于含量为0.2%~0.9%之间的质控样品,8种目标物的平均回收率在63.5%~118.5%之间,RSD在4.61%~15.6%之间。8种目标物的定量限为0.02%。应用该方法测定10份市售聚乙烯食品包装袋和手套,其中6份样品均检测出含有亚磷酸三(2,4-二叔丁苯基)酯(抗氧剂168),含量为0.02%~0.07%,均小于GB 9685-2016规定的聚乙烯类食品接触材料中抗氧剂168的最大使用量(0.2%)。该方法能够满足聚乙烯类产品中8种添加剂的分析要求,可用于食品接触材料风险监测。

Quantitative NMR as a Versatile Tool for the Reference Material Preparation

The assessment of primary calibrator purity is critical for establishing traceability to the International System of Units (SI). Recently, quantitative nuclear magnetic resonance (qNMR) has been used as a purity determination method for reference material development, and many related measurement techniques have been designed to acquire accurate and reliable results. This review introduces the recent advances in these techniques (including multidimensional methods), focusing on the application of qNMR to reference material preparation.

Applications of digital PCR in COVID-19 pandemic.

The coronavirus disease 2019 (COVID‐19) pandemic has led to a public health crisis and global panic. This infectious disease is caused by a novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). Digital polymerase chain reaction (dPCR), which is an emerging nucleic acid amplification technology that allows absolute quantification of nucleic acids, plays an important role in the detection of SARS‐CoV‐2. In this review, we introduce the principle and advantages of dPCR, and review the applications of dPCR in the COVID‐19 pandemic, including detection of low copy number viruses, measurement of the viral load, preparation of reference materials, monitoring of virus concentration in the environment, detection of viral mutations, and evaluation of anti‐SARS‐CoV‐2 drugs. We also discuss the challenges of dPCR in clinical practice.

Incorporation of U, Pb and Rare Earth Elements in Calcite through Crystallisation from Amorphous Calcium Carbonate: Simple Preparation of Reference Materials for Microanalysis

Uncertainty for elemental and isotopic measurements in calcite by LA‐ICP‐MS is largely controlled by the homogeneity of the reference materials (RMs) used for calibration and validation. In order to produce calcite RMs with homogeneous elemental and isotopic compositions, we incorporated elements including U, Pb and rare earth elements into calcite through heat‐ and pressure‐induced crystallisation from amorphous calcium carbonate that was precipitated from element‐doped reagent solution. X‐ray absorption spectra showed that U was present as U(VI) in the synthesised calcite, probably with a different local structure from that of aqueous uranyl ions. The uptake rate of U by our calcite was higher in comparison with synthetic calcite of previous studies. Variations of element mass fractions in the calcite were better than 12% 2RSD, mostly within 7%. The 207Pb/206Pb ratio in the calcite showed < 1% variations, while the 238U/206Pb ratio showed 3–24% variations depending on element mass fractions. Using the synthetic calcite as primary RMs, we could date a natural calcite RM, WC‐1, with analytical uncertainty as low as < 3%. The method presented can be useful to produce calcite with controlled and homogeneous element mass fractions and is a promising alternative to natural calcite RMs for U‐Pb geochronology.

Ariel – a window to the origin of life on early earth?

Is there life beyond Earth? An ideal research program would first ascertain how life on Earth began and then use this as a blueprint for its existence elsewhere. But the origin of life on Earth is still not understood, what then could be the way forward? Upcoming observations of terrestrial exoplanets provide a unique opportunity for answering this fundamental question through the study of other planetary systems. If we are able to see how physical and chemical environments similar to the early Earth evolve we open a window into our own Hadean eon, despite all information from this time being long lost from our planet’s geological record. A careful investigation of the chemistry expected on young exoplanets is therefore necessary, and the preparation of reference materials for spectroscopic observations is of paramount importance. In particular, the deduction of chemical markers identifying specific processes and features in exoplanetary environments, ideally “uniquely”. For instance, prebiotic feedstock molecules, in the form of aerosols and vapours, could be observed in transmission spectra in the near future whilst their surface deposits could be observed from reflectance spectra. The same detection methods also promise to identify particular intermediates of chemical and physical processes known to be prebiotically plausible. Is Ariel truly able to open a window to the past and answer questions concerning the origin of life on our planet and the universe? In this paper, we discuss aspects of prebiotic chemistry that will help in formulating future observational and data interpretation strategies for the Ariel mission. This paper is intended to open a discussion and motivate future detailed laboratory studies of prebiotic processes on young exoplanets and their chemical signatures.

Preparation of a reference material for crude oil trace elements: Study of homogeneity and stability

Trace elements can be found naturally in crude oil or can be added during the production process, transport, or storage. Due to the complexity of the determination of trace elements in crude oil, which is mainly accomplished using multi-element techniques, many reports have been published describing the optimization of instrumental parameters, the development of procedures for sample preparation, and new sample introduction devices. The goal of such research is to improve the sensitivity, precision, and accuracy of the measurements. In all the cases mentioned above, the use of reference materials (RMs) and certified reference materials (CRMs) is recommended to verify the accuracy of the new methods proposed. This paper describes the development of a natural-matrix reference material for quantification of vanadium, nickel, magnesium, sodium, calcium, strontium, and barium in crude oil. 3 kg of crude oil was processed and distributed into 115 units, each containing 20 g. The homogeneity and stability of the prepared reference material were investigated using atomic absorption spectrometry (AAS), inductively coupled plasma optical emission spectrometry (ICP OES), and inductively coupled plasma mass spectrometry (ICP-MS) techniques. The results were evaluated using standard univariate analysis of variance (ANOVA), regression analysis, and principal component analysis (PCA). Statistical evaluation of the data showed good homogeneity and stability of the candidate reference material under the conditions studied.

Quality assessment of the preparation of reference materials of moist solid substances

In this article considers the models of random parameter and random walk as alternative approaches for estimating the mean standard deviation associated with heterogeneity during both the evaluation of the metrological characteristics of reference materials, the quality control of samples prepared from moist solid substances. For the random parameter and random walk models, the behaviour of the basic statistical criteria is described, including the overall mean, standard deviation, standard deviation of the mean and function, obtained both for real experimental data and theoretical measurement results simulated according to the Monte Carlo method. It is shown that the application of the ANOVA method for evaluating the standard deviation associated with heterogeneity should be additionally validated for the materials, whose basic statistical criteria fall under the random walk model.

Characteristic volatile compounds of Monastrell wines

Seventy-five percent of the red wines of the Protected Designation of Origin (PDO) Alicante are based on Monastrell grapes. The wine aroma is one of the most important characteristics linked to the quality and consumers’ preferences. Scopus database was used to gather information about the concentrations ranges of the main volatile compounds present in the Monastrell red wines, with their aromatic descriptions and their detection and/or recognition thresholds. Seventeen volatile compounds were identified as those having a significant contribution to this red wine aroma. However, it is important to indicate that there is a need to continue reviewing critically the threshold values (detection and/or recognition) of the main volatile compounds with a "potentially" significant contribution to the odor/aroma/flavor of the Monastrell wines. This information will be essential in preparing reference materials for trained sensory panels calibration for descriptive sensory evaluation of wines.