Limit of quantification

定量极限
  • 文章类型: Journal Article
    生物传感器作为复杂的设备,将生化反应转化为电信号。当代强调开发具有精细灵敏度和选择性的生物传感器装置是关键的,因为它们具有广泛的功能能力。然而,一个重大挑战在于生物传感器与生物分子的结合亲和力,需要熟练的将相互作用转换和放大为各种信号模式,如电气,光学,重量分析,和电化学输出。克服与敏感性相关的挑战,检测限,响应时间,再现性,和稳定性是必不可少的高效生物传感器的创建。任何生物传感器的制造的中心方面集中于在分析物电极之间形成有效界面,其显著影响整体生物传感器质量。聚合物和大分子体系因其独特的性质和通用的应用而受到青睐。增强这些体系的性质和导电性可以通过引入纳米颗粒或碳质部分来实现。混合复合材料,拥有高级灵敏度等独特的属性组合,选择性,热稳定性,机械灵活性,生物相容性,和可调的电性能,成为生物传感器应用的有希望的候选者。此外,这种方法增强了电化学响应,信号放大,和制造的生物传感器的稳定性,有助于他们的有效性。这篇综述主要探讨了利用大环和大分子共轭体系的最新进展,如酞菁,卟啉,聚合物,等。和他们的混血儿,特别关注生物传感器中的信号放大。它全面涵盖了合成战略,属性,工作机制,以及这些系统检测生物分子如葡萄糖的潜力,过氧化氢,尿酸,抗坏血酸,多巴胺,胆固醇,氨基酸,和癌细胞。此外,这次审查深入探讨了取得的进展,阐明负责信号放大的机制。结论解决了基于大分子的杂种在生物传感器应用中的挑战和未来方向,提供了这个不断发展的领域的简要概述。叙述强调了生物传感器技术进步的重要性,说明智能设计和材料增强在提高各个领域的性能中的作用。
    Biosensors function as sophisticated devices, converting biochemical reactions into electrical signals. Contemporary emphasis on developing biosensor devices with refined sensitivity and selectivity is critical due to their extensive functional capabilities. However, a significant challenge lies in the binding affinity of biosensors to biomolecules, requiring adept conversion and amplification of interactions into various signal modalities like electrical, optical, gravimetric, and electrochemical outputs. Overcoming challenges associated with sensitivity, detection limits, response time, reproducibility, and stability is essential for efficient biosensor creation. The central aspect of the fabrication of any biosensor is focused towards forming an effective interface between the analyte electrode which significantly influences the overall biosensor quality. Polymers and macromolecular systems are favored for their distinct properties and versatile applications. Enhancing the properties and conductivity of these systems can be achieved through incorporating nanoparticles or carbonaceous moieties. Hybrid composite materials, possessing a unique combination of attributes like advanced sensitivity, selectivity, thermal stability, mechanical flexibility, biocompatibility, and tunable electrical properties, emerge as promising candidates for biosensor applications. In addition, this approach enhances the electrochemical response, signal amplification, and stability of fabricated biosensors, contributing to their effectiveness. This review predominantly explores recent advancements in utilizing macrocyclic and macromolecular conjugated systems, such as phthalocyanines, porphyrins, polymers, etc. and their hybrids, with a specific focus on signal amplification in biosensors. It comprehensively covers synthetic strategies, properties, working mechanisms, and the potential of these systems for detecting biomolecules like glucose, hydrogen peroxide, uric acid, ascorbic acid, dopamine, cholesterol, amino acids, and cancer cells. Furthermore, this review delves into the progress made, elucidating the mechanisms responsible for signal amplification. The Conclusion addresses the challenges and future directions of macromolecule-based hybrids in biosensor applications, providing a concise overview of this evolving field. The narrative emphasizes the importance of biosensor technology advancement, illustrating the role of smart design and material enhancement in improving performance across various domains.
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  • 文章类型: Journal Article
    在目前的工作中,开发了一种有效的等度HPLC方法,用于精确和准确地估计片剂形式的维生素D3。色谱条件包括L3硅胶柱(粒径为5μm,4.6mm×250mm),流动相正己烷/乙酸乙酯(85:15v/v),流速为2.0mL/min,检测波长为292nm。新方法的准确性得到了验证,精度,特异性,鲁棒性,和量化限值根据USP/BP和ICH指南的官方专论。记录均匀样品的六个重复的峰面积。得到的平均值为67,301,相对标准偏差(RSD)为0.1741。线性和范围在可接受的范围内,即,0.999,采用回归线分析计算。结果表明,该方法作为RSD是真正可以接受的,流速为0.81%,而对于流动相组成,是0.72%,在可接受的范围内。检测限(LOD)和定量限(LOQ)值分别为0.0539µg/mL和0.1633µg/mL,分别。根据国际协调委员会准则,该方法的日内和日间精度的RSD百分比被认为是可以接受的。所开发的方法有可能在剂型片剂的常规分析过程中用于维生素D3的检测和定量。
    In the present work, an efficient isocratic HPLC method was developed for the precise and accurate estimation of vitamin D3 in tablet form. The chromatographic conditions comprised an L3 silica column (5 µm in particle size, 4.6 mm × 250 mm) with a mobile phase n-hexane/ethyl acetate (85:15 v/v) with a flow rate of 2.0 mL/min and a detection wavelength of 292 nm. The new methodology was validated for accuracy, precision, specificity, robustness, and quantification limits according to an official monograph of USP/BP and ICH guidelines. The peak areas of the six replicates of the homogeneous sample were recorded. The mean value obtained was 67,301, and the relative standard deviation (RSD) was 0.1741. The linearity and range were in the acceptable bounds, i.e., 0.999, which was calculated using regression line analysis. The results show that the method is truly acceptable as the RSD, as the flow rate was 0.81%, while for the mobile phase composition, it was 0.72%, which lies in the acceptable range. The limit of detection (LOD) and the limit of quantification (LOQ) values were 0.0539 µg/mL and 0.1633 µg/mL, respectively. The % RSD of the intra and inter-day precision of the method was deemed acceptable according to the international commission for harmonization guidelines. The developed method has potential to be used for the detection and quantification of vitamin D3 during routine analysis for tablets in dosage form.
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  • 文章类型: Journal Article
    由于担心对牲畜的直接毒性以及食物链中农药残留积累的风险,饲料作物中农用化学品的使用受到限制。小麦和大麦可以用作绿色饲料和青贮饲料,绿色饲料和青贮饲料中除草剂残留量的估算对于确保奶牛的安全具有重要意义。进行了为期两年的田间试验,以研究小麦和大麦的绿色饲料和青贮饲料中的二甲戊灵残留。在这两种谷类作物中,作为出苗前施用二甲戊灵(1.125kga.i./ha)以及未喷雾的对照。二甲戊灵在饲料中的残留,青贮饲料,使用气相色谱-串联质谱法(GC-MS/MS)估算土壤。在收获的时候,在两个作物季节中,小麦和大麦的饲料和青贮饲料中的二甲正灵残留量均低于定量限(<0.01mg/kg)。二甲戊灵可以安全地用于冬季谷物中的杂草控制,用于饲料和青贮饲料。
    Use of agro-chemicals in forage crops is restricted due to the fear of direct toxicity to livestock and risk of pesticide residue accumulation in the food chain. Wheat and barley can be used as green fodder and silage, and herbicide residue estimation in green fodder and silage is important for ensuring the safety of dairy cattle. A field experiment was conducted for two years to study pendimethalin residues in the green fodder and silage of wheat and barley. In both cereal crops, pendimethalin (1.125 kg a.i./ha) was applied as pre-emergence along with an unsprayed control. Pendimethalin residues in fodder, silage, and soil were estimated using gas chromatography-tandem mass spectrometry (GC-MS/MS). At harvest, pendimethalin residues in fodder and silage of wheat and barley were below the limit of quantification (<0.01 mg/kg) during both crop seasons. Pendimethalin can be safely used for weed control in winter cereals grown for fodder and silage.
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  • 文章类型: Journal Article
    牡蛎中诺如病毒(NoV)的食品安全风险备受关注。为了评估暴露的风险,应首先获取每个牡蛎中所含NoV拷贝数的分布,以全面量化相关风险。然而,低于定量限的分布部分不能通过实验室检测方法直接获得,这妨碍了准确的评估。为了解决这个具有挑战性的问题,提出了一种系统方法(通过汇集采样的分布推断方法),以根据n=2的汇集样本的所有测量结果来推断分布的不可观察部分。使用卷积积分和实数编码遗传算法进行推断,此方法对原始分布的类型或属性没有要求,也不要求历史数据,甚至对分布的可观察部分和不可观察部分之间的关系也没有要求。对各种类型的模拟数据集进行了一系列实验,包括正态分布,均匀分布,伽马分布,对数正态分布,零膨胀泊松分布,他们的组合,甚至它们的拼接,涵盖牡蛎NoV场景和更一般场景中的常见分销类型。结果表明,几乎所有推断的模拟数据及其原始对应数据都通过了Kolmogorov-Smirnov测试,这意味着它们是相同分布的关键。基于这种方法,为研究人员开发了一个现成的网络系统,通过对NoV甚至其他物质的检测进行汇总采样测量,推断其原始分布.
    Norovirus (NoV) in oysters is a food safety risk of much concern. In order to assess the risk of the exposure, the distribution of the number of NoV copies contained in each oyster should be acquired first for comprehensively quantifying the associated risks. However, the part of the distribution below the limit of quantification cannot be obtained directly by laboratory detecting methods, which hampers accurate assessment. To tackle this challenging problem, a systematic method (Distribution Inference Method by Pooled Sampling) is proposed to infer the unobservable part of distribution based upon all measurements of the pooled samples with n = 2. Using convolutional integrals and real-coded genetic algorithm for inferring, this method has neither requirements for the type or properties of the original distribution, nor requirements for historical data, even nor requirements for the relationship between observable and unobservable parts of the distribution. A series of experiments were conducted on simulated datasets of a variety of types, including normal distribution, uniform distribution, gamma distribution, lognormal distribution, zero-inflated Poisson distribution, their combinations, and even their splicing, covering common distribution types in oyster NoV scenario and more general scenarios. The results show that almost all inferred simulation data and their original counterparts passed Kolmogorov-Smirnov tests, which implies that they are essential of the same distribution. Based on this method, a ready-to-use web system was developed for researchers to infer their original distribution with pooled-sampling measurements from the detection of NoV or even other substances.
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  • 文章类型: Journal Article
    食品污染数据的处理往往是一个挑战,因为这些数据往往是左审查,由正值和未检测到的值组成。后面的观察结果没有量化,只提供它们低于实验室特定阈值的信息。除了确定性方法,通过用固定阈值或空值替换未检测到的值来简化处理,越来越多的人对应用随机方法处理未量化值感兴趣.在这项研究中,为了分析脱氧雪腐镰刀菌烯醇的污染数据,一种可能存在于面食和面食替代产品中的霉菌毒素。介绍了所提出的技术在审查脱氧雪腐镰刀菌烯醇发生数据中的应用。将结果与使用确定性技术(替代方法)获得的结果进行比较。在这种情况下,随机方法似乎提供了更准确的,对左删失事件数据问题的无偏见和现实的解决方案。然后,可以根据消费数据使用完整的值样本来估计普通人群对脱氧雪腐镰刀菌烯醇的暴露。
    The handling of data on food contamination frequently represents a challenge because these are often left-censored, being composed of both positive and non-detected values. The latter observations are not quantified and provide only the information that they are below a laboratory-specific threshold value. Besides deterministic approaches, which simplify the treatment through the substitution of non-detected values with fixed threshold or null values, a growing interest has been shown in the application of stochastic approaches to the treatment of unquantified values. In this study, a multiple imputation procedure was applied in order to analyze contamination data on deoxynivalenol, a mycotoxin that may be present in pasta and pasta substitute products. An application of the proposed technique to censored deoxynivalenol occurrence data is presented. The results were compared to those attained using deterministic techniques (substitution methods). In this context, the stochastic approach seemed to provide a more accurate, unbiased and realistic solution to the problem of left-censored occurrence data. The complete sample of values could then be used to estimate the exposure of the general population to deoxynivalenol based on consumption data.
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  • 文章类型: Journal Article
    由于1,4-二恶烷被怀疑为人类致癌物,因此必须开发有效的检测方法。它在食品和环境资源中具有高度的流动性。在这方面,本实验已通过使用静态顶空(SH)隔离来开发可靠和选择性的检测和测量方法,然后是气相色谱-质谱(GC-MS)。开发了一种新方法来测定聚乙二醇600(PEG600)中的1,4-二恶烷含量。讨论了SH-GC-MS的最佳条件。在MS的SIM模式下,1,4-二恶烷和1,4-二恶烷-d8的代表离子分别为88和96,和SIM模式的峰被分离和确认。该方法的线性范围为0.25至100mg/L,测定系数(R2)≥0.999。通过在各种食品添加剂中的加标回收率证明了该方法的适用性(即,氯酒石酸氢盐,氯化胆碱,聚山梨酯20和60,以及PEG1000)。测试样品的所有加标回收率在89.50-102.68%的范围内,精密度为0.44-11.22%。这些发现为食品安全检查提供了一种新的分析方法,并可适用于广泛确保食品安全以及环境和公共卫生。
    Efficient detection methods must be developed for 1,4-dioxane due to its suspected status as a human carcinogen, which is highly mobile in food and environmental resources. In this regard, this experiment has been conducted to develop reliable and selective detection and measurement methods by using static headspace (SH) isolation, followed by gas chromatography-mass spectrometry (GC-MS). A new method was developed for determining the spiked 1,4-dioxane contents in a polyethylene glycol 600 (PEG 600). The optimal condition for SH-GC-MS was discussed. The representative ions of 1,4-dioxane and 1,4-dioxane-d8 in the SIM mode of MS are 88 and 96, respectively, and the peaks of the SIM mode were separated and confirmed. The linear range for the method covers 0.25 to 100 mg/L with a coefficient of determination (R2)  ≥  0.999. The method applicability was demonstrated by spike recovery across a variety of food additives (i.e., chlorine bitartrate, choline chloride, polysorbate 20 and 60, and PEG 1000). All spike recovery from the tested samples was in the range of 89.50-102.68% with a precision of 0.44-11.22%. These findings suggest a new analytical method for food safety inspection, and could be applicable for ensuring the safety of foods and environmental and public health on a broad scale.
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  • 文章类型: Journal Article
    在废水处理期间,微污染物仅被部分消除,可能对人类健康和水生生态系统构成风险。由于缺乏低于一组重要的微污染物的定量极限(LOQ)的可用浓度,因此目前可能低估了这些物质的潜在影响。这里,以法国的规模调查了261种有机微污染物对人类健康和水生环境的潜在影响。即使浓度低于LOQ,发现某些微污染物具有重大的潜在影响。对于未测量的浓度,使用了由具有不同LOQ的几个数据集构建的全球浓度分布。通过忽略未测量的微污染物,对人类健康和水生环境的潜在影响被低估了300%。某些物质,如肼,异狄氏剂,或2,3,7,8-四CDD,可能会导致非常强烈的潜在影响,即使有未测量的浓度水平。此外,通常使用LOQ/2替代未测量浓度也似乎高估了潜在影响.本作品可以适应任何其他隔间或地理环境。
    During wastewater treatment, micropollutants are only partly eliminated and may present a risk for human health and aquatic ecosystems. The potential impacts these substances may have are currently underestimated due to the lack in available concentrations that lie below the limit of quantification (LOQ) for an important set of micropollutants. Here, the potential impacts due to 261 organic micropollutants on human health and aquatic environments were investigated at the scale of France. Even with concentrations below the LOQ, certain micropollutants were found to have a significant potential impact. For unmeasured concentrations, a global concentration distribution built from several datasets with different LOQ was used. By disregarding the unmeasured micropollutants, the potential impacts have been underestimated by >300 % on both human health and aquatic environments. Certain substances, such as hydrazine, endrin, or 2,3,7,8-TetraCDD, could lead to very strong potential impacts, even with unmeasured concentration levels. Moreover, the usual convention of LOQ/2 to replace unmeasured concentrations also appeared to overestimate the potential impact. The present work can be adapted to any other compartment or geographical context.
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  • 文章类型: Meta-Analysis
    硒(Se)摄入的有益和有害影响之间的复杂平衡意味着它在食物中的定量需要正确完成。因此,在这次审查中,我们将105篇文章系统化,以确定研究最多的方法,分析技术,和食物矩阵。在所采用的分析技术中,电感耦合等离子体质谱(ICP-MS)(n=29)是最常用的方法。消化食物基质中硒的最普遍的水解方法涉及使用硝酸结合超声,提高了产量和消化时间。当总Se定量占Se(IV)和Se(VI)的总和(94.4-99.4%)和SeCys(88-96.5%)时,可实现最佳恢复值。这些发现与推进方法论方法有关,他们的结果强调了开发替代方案的重要性,更快,以及食品和饮料中硒定量的低成本协议。
    The intricate balance between the beneficial and harmful effects of selenium (Se) intake means that its quantification in food needs to be done correctly. Therefore, in this review, we systematized 105 articles to identify the most studied methodologies, analytical techniques, and food matrices. Among the analytical techniques employed, inductively coupled plasma mass spectrometry (ICP-MS) (n = 29) emerged as the most commonly used method. The most prevalent hydrolysis methodology to digest Se in food matrices involved the use of nitric acid combined with ultrasound, which improved both the yield and digestion time. Optimal recovery values were achieved when total Se quantification accounted for the sum of Se(IV) and Se(VI) (94.4-99.4%) and for SeCys (88-96.5%). These findings are relevant for advancing methodological approaches, and their results emphasize the importance of developing alternative, faster, and lower-cost protocols for Se quantification in foods and beverages.
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  • 文章类型: Journal Article
    临床相关的抗生素耐药性在人类中的广泛发生,动物,和环境推动了灵敏、准确的检测和量化方法的发展。宏基因组学和定量PCR(qPCR)是最常用的方法之一。在这项研究中,我们旨在评估和比较这些方法在动物粪便中筛选抗生素抗性基因的性能,废水,和水样。水和废水样品来自医院废水,两个处理厂的不同处理阶段,以及排放点的接收河。动物样品来自猪和鸡的粪便。抗生素抗性基因覆盖率,灵敏度,并对定量信息的有用性进行了分析和讨论。虽然这两种方法都能够区分耐药性谱并检测猪和鸡粪便的梯度逐步混合物,qPCR对检测水/废水中的一些抗生素抗性基因具有更高的灵敏度。此外,预测和观察到的抗生素抗性基因定量的比较揭示了qPCR的更高准确性。宏基因组学分析,虽然不那么敏感,与qPCR相比,提供了明显更高的抗生素抗性基因覆盖率。讨论了两种方法的互补性以及根据研究目的选择最佳方法的重要性。
    The widespread occurrence of clinically relevant antibiotic resistance within humans, animals, and environment motivates the development of sensitive and accurate detection and quantification methods. Metagenomics and quantitative PCR (qPCR) are amongst the most used approaches. In this study, we aimed to evaluate and compare the performance of these methods to screen antibiotic resistance genes in animal faecal, wastewater, and water samples. Water and wastewater samples were from hospital effluent, different treatment stages of two treatment plants, and of the receiving river at the discharge point. The animal samples were from pig and chicken faeces. Antibiotic resistance gene coverage, sensitivity, and usefulness of the quantitative information were analyzed and discussed. While both methods were able to distinguish the resistome profiles and detect gradient stepwise mixtures of pig and chicken faeces, qPCR presented higher sensitivity for the detection of a few antibiotic resistance genes in water/wastewater. In addition, the comparison of predicted and observed antibiotic resistance gene quantifications unveiled the higher accuracy of qPCR. Metagenomics analyses, while less sensitive, provided a markedly higher coverage of antibiotic resistance genes compared to qPCR. The complementarity of both methods and the importance of selecting the best method according to the study purpose are discussed.
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  • 文章类型: Journal Article
    根据法规(EC)No396/2005的第43条,欧盟委员会要求EFSA考虑新的毒理学参考值,对现有的草甲胺的最大残留水平(MRL)进行风险评估。此外,如果需要确保充分的消费者保护,应提出低于立法中目前规定的量化限额(LOQ)。EFSA执行了各种消费者暴露计算场景,根据欧盟农药残留参考实验室(EURLs)的建议,考虑可用于草酰胺现有用途的风险评估值以及降低几种植物和动物商品的LOQ。根据消费者暴露评估的结果,考虑到许可使用草胺的作物的风险评估值和剩余商品的LOQ中现有的欧盟MRL(情景1),在34种饮食中发现了长期的消费者摄入问题.确定了各种作物的急性接触问题,包括目前被授权使用草酰胺的作物:香蕉,土豆,甜瓜,黄瓜,胡萝卜,西瓜,西红柿,西葫芦,欧洲防风草,盐和茄子/茄子。在暴露计算情景3下,考虑将所有MRL降低到最低分析可实现的定量极限,EFSA得出的结论是,仍然不能排除长期的消费者接触问题。同样,对16种商品确定了消费者对急性接触的担忧,包括已知授权用途的作物:土豆,甜瓜,西瓜和西红柿,即使对于这些作物,也考虑了EURL提出的较低LOQ。EFSA不可能对当前阶段的计算暴露进行进一步改进,但是EFSA确定了一系列商品,这些商品的LOQ低于常规可实现的水平,有望显着降低消费者的风险敞口,并且需要进行风险管理决策。
    In accordance with Article 43 of Regulation (EC) No 396/2005, the European Commission requested EFSA to perform a risk assessment of the existing maximum residues levels (MRLs) for oxamyl considering the new toxicological reference values. Additionally, if needed to ensure adequate consumer protection, lower limits of quantification (LOQs) than those currently established in the legislation should be proposed. EFSA performed various consumer exposure calculation scenarios, considering the risk assessment values as available for the existing uses of oxamyl and the lowering of LOQs for several plant and animal commodities as suggested by the European Union Reference Laboratories for Pesticide Residues (EURLs). Based on the results of the consumer exposure assessment calculated considering the risk assessment values for crops with authorised oxamyl uses and the existing EU MRLs at the LOQ for remaining commodities (scenario 1), chronic consumer intake concerns were identified for 34 diets. Acute exposure concerns were identified for a wide range of crops, including crops with currently authorised oxamyl uses: bananas, potatoes, melons, cucumbers, carrots, watermelons, tomatoes, courgettes, parsnips, salsifies and aubergines/eggplants. Under exposure calculation scenario 3, which considered lowering of all MRLs to the lowest analytically achievable limits of quantification, EFSA concludes that chronic consumer exposure concerns can still not be excluded. Similarly, acute consumer exposure concerns were identified for 16 commodities, including crops with known authorised uses: potatoes, melons, watermelons and tomatoes, even though for these crops a lower LOQ as proposed by the EURLs were considered. Further refinements of the calculated exposure at the current stage were not possible by EFSA, but EFSA identified a list of commodities for which a lower LOQ than routinely achievable is expected to significantly reduce the consumer exposure and for which a risk management decision is required.
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