Experimental designs

实验设计
  • 文章类型: Journal Article
    大约70年前有人建议使用对数喷雾器,但是它还没有被认真地用于研究和开发,以及随后的植物保护产品注册。对数喷雾器仅通过演示实验向最终用户和其他人展示植物保护产品的工作原理。在现场实验中拟合剂量反应曲线,然而,产生了很多重要的信息,例如,提取各种有效场率水平(例如,ED20、ED50和ED80)。很少在植物保护产品注册中使用它的原因之一是迄今为止剂量响应曲线回归难以拟合;注册要求仅侧重于方差分析。另一个所谓的障碍是对数图具有系统性,不是随机分布的场率。本文介绍了一些问题,即如何通过考虑自相关性来非随机分析场率,以通过评估功效使对数喷雾器可口作为注册文件,选择性,环境副作用,植物保护产品的一般毒性,和成本效益。精准农业的发展,无人机技术,数据捕获和后续分析的自动化可以使对数喷雾器成为许多ANOVA实验的具有成本效益的替代方案,并且几乎没有固定的现场速率,以帮助精确喷洒农药,从而减少不必要的环境副作用。©2024化学工业学会。
    A logarithmic sprayer was suggested about 70 years ago, but it has not yet been seriously used in research and development, and subsequent registration of plant protection products. Logarithmic sprayers have resorted to mere demonstration experiments to show end users and others how plant protection products work. Fitting dose-response curves in field experiments, however, generates much essential information, e.g., extraction of various effective field rate levels (e.g., ED20, ED50, and ED80). One of the reasons for it rarely being used in the registration of plant protection products is that the dose-response curve regression was hitherto difficult to fit; the registration requirement solely focuses on analyses of variance. Another alleged obstacle is that the logarithmic plots have systematically, not randomly distributed field rates. This paper goes through some of the problems of how to non-randomly analyze field rates by taking autocorrelation into account to make the logarithmic sprayer palatable as registration documentation by assessing efficacy, selectivity, environmental side effects, general toxicity of plant protection products, and cost-effectiveness. The development in precision agriculture, drone technology, and automation of data capture and subsequent analysis could make the logarithmic sprayer a cost-effective alternative to numerous ANOVA experiments with very few fixed field rates to aid the precision spraying of pesticides and thus reduce unnecessary environmental side effects. © 2024 Society of Chemical Industry.
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  • 文章类型: Journal Article
    实验是有用的科学工具,可以通过操纵感兴趣的变量来测试假设,同时控制其他可能使结果及其解释产生偏差或混淆的因素。为了确保准确性和再现性,实验必须有透明和可重复的方法。由于切碎机无脊椎动物在有机物加工中的重要性,碳循环,和营养循环,我们通过实验测试了微观世界实验中不同方法对碎纸机消耗和生存的影响。我们发现碎纸机物种,案件的存在与否,并且在微观世界中使用或不使用气泵不会影响切碎机的性能(即,消费和生存)。此外,水的类型(溪流或瓶装)不会影响切碎机的性能。另一方面,光量对碎纸机性能有负面影响,具有恒定的光(即,24h)减少碎纸机消耗和生存。我们的结果表明,使用不同的方法并不总是导致结果的变化,从而确保可比性。然而,光度是进行微观实验时值得关注的关键因素。我们的发现提供了有价值的见解,可以帮助研究人员设计来自新热带流的碎纸机的实验,并进行系统的评论和荟萃分析。
    Experiments are useful scientific tools for testing hypotheses by manipulating variables of interest while controlling for other factors that can bias or confuse the results and their interpretation. To ensures accuracy and reproducibility, experiments must have transparent and repeatable methodologies. Due to the importance of shredder invertebrates in organic matter processing, carbon cycling, and nutrient cycling, we tested experimentally the effect of different methodological approaches in microcosm experiments on the consumption and survival of shredders. We found that the shredder species, the presence or absence of the case, and the use or non-use of air-pumps in the microcosms did not affect shredder performance (i.e., consumption and survival). Furthermore, the type of water (stream or bottled) did not affect shredder performance. On the other hand, the amount of light had a negative effect on shredder performance, with constant light (i.e., 24 h) reducing shredder consumption and survival. Our results demonstrate that the use of different methodologies does not always result in changes in outcomes, thus ensuring comparability. However, luminosity is a critical factor that deserves attention when conducting microcosm experiments. Our findings provide valuable insights that can assist researchers in designing experiments with shredders from neotropical streams and conducting systematic reviews and meta-analyses.
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  • 文章类型: Journal Article
    研究了直接引入样品的热解吸(TD)与GC-MS联用,以分析污染沉积物中的石蜡烃(HC)。TD-GC-MS有时用于分析大气颗粒中的石蜡HC,但很少用于直接从沉积物中解吸。所以,新的TD方法论,应用于沉积物,需要发展,优化和验证。进行了明确的筛选实验设计,以区分TD效率的关键因素,来自含有各种有机质(OM)量的模型沉积物。低分子量HCs的提取行为与高分子HMW-HCs明显不同,但是使用很少的沉积物(5毫克)发现了折衷方案,高温速率(55°Cmin-1)和最终温度(350°C)。线性HC(n-C10至n-C40)可以使用矩阵匹配校准方法进行定量,具有非常低的检测限(3.8-13.4ng)。总的链烷烃的量也被确定为预定当量碳范围之间的未拆分组分的总和。将开发的无溶剂方法与优化的溶剂微波辅助萃取(MAE)进行了比较。与MAE相比,TD的基体效应可能更高,但取决于沉积物基质。当基质效应强烈时,特别是在HMW-HCs信号耗尽时,用纯无孔砂稀释有利于准确定量。已解决和未解决的HCs的总和给出了MAE和TD提取之间的可比结果,除了大于C30的烷烃,它们通过TD定量提取较少。然而,TD-GC-MS比MAE-GC-MS更灵敏。因此,TD-GC-MS可用于分析含有大量石蜡HCs(C9-C34)的沉积物,并且具有全自动的优点,很少的样品制备和操作员干预,使用非常低量的溶剂,产生很少的废物。
    Direct sample introduction thermal desorption (TD) coupled to GC-MS was investigated for the analysis of paraffinic hydrocarbons (HCs) from polluted sediments. TD-GC-MS is sometimes used for analysing paraffinic HCs from atmospheric particles but rarely for their direct desorption from sediments. So, the new TD methodology, applied to sediments, required development, optimization and validation. A definitive screening experimental design was performed to discriminate the critical factors on TD efficiency, from model sediments containing various organic matter (OM) amounts. Low molecular weight HCs had extraction behaviours markedly different from high molecular ones (HMW-HCs), but a compromise was found using very few sediment amount (5 mg), high temperature rate (55 °C min-1) and final temperature (350 °C). Linear HCs (n-C10 to n-C40) could be quantified using the matrix-matched calibration method, with very low detection limits (3.8-13.4 ng). The amount of the overall paraffinic alkanes was also determined as a sum of unresolved components between predefined equivalent carbon ranges. The developed solventless methodology was compared to an optimized solvent microwave assisted extraction (MAE). Matrix effects could be higher for TD compared to MAE but it depended on sediment matrix. When matrix effect was strong, particularly on HMW-HCs signal depletion, a dilution with pure non-porous sand was favourable for accurate quantification. The sum of resolved and unresolved HCs gave comparable results between MAE and TD extractions, with an exception of alkanes greater than C30 which were less quantitatively extracted via TD. However, TD-GC-MS was more sensitive than MAE-GC-MS. So TD-GC-MS is useful for analyzing sediments containing a great range of paraffinic HCs (C9-C34) and it has the advantages of being fully automated, with few sample preparation and operator intervention, using very low amounts of solvent, and generating few wastes.
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  • 文章类型: Journal Article
    作物改进工作已经利用田间实验单元的布置来模拟空间趋势的新方法。这些方法在预测评估基因型的遗传潜力方面显示出改进。然而,这些工具的使用可能会受到这些产品的暴露和可访问性的限制。此外,这些新方法通常要求植物科学家熟悉用于实现它们的编程环境;限制了决策的数据分析效率。这些挑战导致了Bean先生的发展,一个易于访问和用户友好的工具,具有全面的图形可视化界面。该应用程序集成了描述性分析,分散和集中的措施,线性混合模型拟合,多环境试验分析,因子分析模型,和基因组分析。所有这些功能旨在帮助植物育种者和从事农业田间试验的科学家更快地做出明智的决定。Mr.Bean可在https://github.com/AparicioJohan/MrBeanApp下载。
    Crop improvement efforts have exploited new methods for modeling spatial trends using the arrangement of the experimental units in the field. These methods have shown improvement in predicting the genetic potential of evaluated genotypes. However, the use of these tools may be limited by the exposure and accessibility to these products. In addition, these new methodologies often require plant scientists to be familiar with the programming environment used to implement them; constraints that limit data analysis efficiency for decision-making. These challenges have led to the development of Mr.Bean, an accessible and user-friendly tool with a comprehensive graphical visualization interface. The application integrates descriptive analysis, measures of dispersion and centralization, linear mixed model fitting, multi-environment trial analysis, factor analytic models, and genomic analysis. All these capabilities are designed to help plant breeders and scientist working with agricultural field trials make informed decisions more quickly. Mr.Bean is available for download at https://github.com/AparicioJohan/MrBeanApp.
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  • 文章类型: Journal Article
    快速确定在大流行期间在社区中使用的有效治疗方法对于个人的福祉以及医疗保健系统和社会的可持续性至关重要。此外,确定无效的治疗方法减少了研究浪费,避免人们不必要的副作用,使购买和储存药物的成本合理化,并减少不适当的药物使用。然而,只有一小部分针对SARS-CoV-2感染的治疗试验已经在初级保健中进行:大多数开放为时已晚,努力招募,很少产生可操作的结果。参与研究通常受到一个人居住或接受医疗保健的限制,和试验参与者可能不代表那些治疗的目的。
    ALIC4E,原理和正在进行的全景试验已经随机分配了超过40,500名COVID-19患者。这种个人观点描述了这些试验是如何创新的:试验设计(通过使用新颖的自适应平台设计);试验交付(通过补充传统的基于地点的招募(“患者来研究”)与机制,使病人,有传染性的人参加而不必离开家(“把研究带给人民”),通过解决“反向研究参与法”,这凸显了那些贡献最大的人所面临的不成比例的障碍,并从中受益,研究,并通过评估9种药物来改变证据基础,以支持全球范围内针对COVID-19的指南和护理决策,并为抗菌药物管理做出贡献。
    原则和全景试验代表了创新和包容性的模式,并举例说明初级保健在应对紧迫的全球卫生挑战方面的潜力。
    自适应平台试验可以有效地并行评估几种治疗方法,并依次“将研究带给人们”可以通过使病人,使参与民主化。有传染性的人从家里做出贡献,在全国范围内,原则和全景试验在试验设计和交付方面进行了创新,为社区中的9种COVID-19治疗提供了证据。
    UNASSIGNED: Rapid identification of effective treatments for use in the community during a pandemic is vital for the well-being of individuals and the sustainability of healthcare systems and society. Furthermore, identifying treatments that do not work reduces research wastage, spares people unnecessary side effects, rationalises the cost of purchasing and stockpiling medication, and reduces inappropriate medication use. Nevertheless, only a small minority of therapeutic trials for SARS-CoV-2 infections have been in primary care: most opened too late, struggled to recruit, and few produced actionable results. Participation in research is often limited by where one lives or receives health care, and trial participants may not represent those for whom the treatments are intended.
    UNASSIGNED: The ALIC4E, PRINCIPLE and the ongoing PANORAMIC trial have randomised over 40,500 people with COVID-19. This personal view describes how these trials have innovated in: trial design (by using novel adaptive platform designs); trial delivery (by complementing traditional site-based recruitment (\'the patient comes to the research\') with mechanisms to enable sick, infectious people to participate without having to leave home (\'taking research to the people\'), and by addressing the \'inverse research participation law,\' which highlights disproportionate barriers faced by those who have the most to contribute, and benefit from, research, and; in transforming the evidence base by evaluating nine medicines to support guidelines and care decisions world-wide for COVID-19 and contribute to antimicrobial stewardship.
    UNASSIGNED: The PRINCIPLE and PANORAMIC trials represent models of innovation and inclusivity, and exemplify the potential of primary care to lead the way in addressing pressing global health challenges.
    Adaptive platform trials can efficiently evaluate several treatments in parallel and sequentially‘Taking research to people’ can democratise participation by enabling sick, contagious people to contribute from home, country-wideThe PRINCIPLE and PANORAMIC Trials innovated in trial design and delivery to produce evidence on nine treatments for COVID-19 in the community.
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  • 文章类型: Journal Article
    尽管有证据表明健康饮食在预防癌症方面的作用,在美国(U.S.)拉丁美洲人/癌症幸存者的癌症诊断后,营养如何支持积极的健康结果鲜为人知。这项范围审查的目的是了解营养干预在支持拉丁美洲/美国癌症幸存者健康生存方面的潜在益处。评估,并总结了现有的证据。通过对同行评审数据库和灰色文献的全面搜索,确定了潜在的相关研究。符合条件的研究包括拉丁裔/接受营养教育的成年癌症幸存者,饮食变化,或行为干预;以及与营养相关的健康结果。使用表格提取和总结数据。该综述包括10项随机对照试验,拉丁裔/癌症幸存者的样本或子样本。干预措施主要集中在乳腺癌幸存者身上。结果表明,一些证据表明,饮食行为,比如水果和蔬菜的摄入,与积极的结果有关,比如降低患癌症的风险(通过DNA甲基化的变化),降低乳腺癌复发风险(通过炎症生物标志物的变化),或改善对健康状况的感知。研究结果强调了拉丁美洲人/成年人需要社区参与和文化相关的营养干预措施,特别是对于农村社区;和创新的干预方法,包括长期随访的m/ehealth方法。
    Despite evidence for the role of healthy diets in preventing cancer, little is known about how nutrition can support positive health outcomes after a cancer diagnosis for Latino/a cancer survivors in the United States (U.S.). The purpose of this scoping review is to understand the potential benefits of nutrition interventions in supporting healthy survivorship among Latino/a cancer survivors in the U.S. A team compiled, evaluated, and summarized the available evidence. Potentially relevant studies were identified from a comprehensive search of peer-reviewed databases and the gray literature. Eligible studies included Latino/a adult cancer survivors with a nutrition education, dietary change, or behavioral intervention; and a nutrition-related health outcome. Data were extracted and summarized using tables. The review included 10 randomized controlled trials, with samples or subsamples of Latino/a cancer survivors. Interventions mostly focused on breast cancer survivors. The results showed some evidence that dietary behaviors, like fruit and vegetable intake, were related to positive outcomes, like a decreased risk of cancer (through changes in DNA methylation), decreased risk breast cancer recurrence (through changes in inflammatory biomarkers), or improved perception of health status. The findings highlight a need for community-engaged and culturally relevant nutrition interventions for Latino/a adults, especially for rural communities; and innovative intervention approaches, including m/ehealth approaches with long-term follow-up.
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  • 文章类型: Journal Article
    被动采样器积累有机污染物的速率取决于现场暴露条件,如淡水流速,水温和水质。时间加权平均浓度可以通过使用校正过程如性能参考化合物(PRC)方法来确定。这项研究提出了一种新的方法来预测农药在不同暴露条件下在聚二甲基硅氧烷涂层搅拌棒中的积累行为,并为每种农药分配特定的PRC以进行定量。我们使用了一种实验设计,在流通系统中运行了13种农药的8种同时积累动力学和3种PRC候选物的消除动力学,以确定流速的影响。水温和溶解有机物对动力学常数的影响。我们确定了对每种农药积累有显着影响的参数,并为每种农药分配了PRC候选物。然后,我们使用判别函数分析来找到通过其理化性质对13种农药的积累有显着影响的参数,并通过随机方法预测其他7种农药的参数。与传统方法相比,该方法为确定PRC提供了更好的框架,以确定未来监测工作中的无偏浓度。
    Passive samplers accumulate organic contaminants at rates that depend on in-field exposure conditions such as freshwater flow velocity, water temperature and water quality. Time-weighted average concentrations can be determined by using a correction process such as the performance reference compound (PRC) method. This study presented a new approach to predict the accumulation behavior of pesticides in polydimethylsiloxane-coated stir bars under different exposure conditions and assign a specific PRC to each pesticide for quantitative purposes. We used an experimental design with eight simultaneous accumulation kinetics of 13 pesticides and elimination kinetics of three PRC candidates run in a flow-through system to determine the effects of flow velocity, water temperature and dissolved organic matter on the kinetic constants. We identified the parameters that had a significant effect on the accumulation of each pesticide and assigned a PRC candidate to each pesticide. We then used a discriminant function analysis to find the parameters that had a significant effect on accumulation of the 13 pesticides via their physical-chemical properties and to predict through a stochastic approach the parameters for seven other pesticides. This approach provides a better framework for identifying a PRC than conventional methods to determine unbiased concentrations in future monitoring efforts.
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  • 文章类型: Journal Article
    目前的研究重点是研究如何使用实验设计方法提高加气泻药和吸附联合工艺处理Loukkos地区橄榄工业的橄榄厂废水(OMWW)的效率。后者使优化实验条件成为可能,如石灰的质量浓度,粉状活性炭(AC)的质量浓度,和搅拌速度(Va),这是预期治疗所需的,为了控制必要的物理化学参数评估后的结果,即pH值,总悬浮固体(TSS),化学需氧量(COD),变色率,和多酚的含量。进行这项研究所需的实验条件是在1.4和1.75g/l之间的AC,在23和32rpm之间的搅拌速度,石灰的质量浓度在0.88至1.3g/l之间。该实验的结果表明,在向混合物中添加石灰之后用原型II处理OMWW导致分析参数估计减少85%。pH值,TSS,COD,COD变色率,多酚含量均从初始值4.87、0.63(g/l)降低,80.3(g(O2/l)),0.8%,和1.45(g/l),分别,最终值为6.92、0.12(g/l),12,0.16%,和0.25(g/l)。与仅使用粉末状活性炭处理原型I的过程中获得的结果相比,这些结果非常重要,显示约70%的减少率。
    The current study focuses on investigating how to improve the efficacy of the combined process of aerated lagooning and adsorption for the treatment of olive mill wastewater (OMWW) from the olive industries in the Loukkos region using the design of experiments approach. The latter made it possible to optimize the experimental conditions, such as the mass concentration of lime, the mass concentration of powdered activated carbon (AC), and the speed of agitation (Va), which are required for the envisaged treatment, in order to control the results after the evaluation of the necessary physicochemical parameters, namely pH, total suspended solids (TSS), chemical oxygen demand (COD), rate of discoloration, and content of polyphenols. The experimental conditions necessary to carry out this study were between 1.4 and 1.75 g/l for AC, between 23 and 32 rpm for the stirring speed, and between 0.88 and 1.3 g/l for the mass concentration of lime. The results of this experiment showed that treating OMWW with the prototype II after adding lime to the mixture resulted in an estimated 85% reduction in the analyzed parameters. The pH, TSS, COD, discoloration rate, and polyphenol content were all reduced from initial values of 4.87, 0.63 (g/l), 80.3 (g (O2/l)), 0.8%, and 1.45 (g/l), respectively, to final values of 6.92, 0.12 (g/l), 12, 0.16%, and 0.25 (g/l). These results are highly significant when compared to those obtained during the treatment of prototype I using only powdered activated carbon, which showed a reduction rate of around 70%.
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  • 文章类型: Journal Article
    移动和无线技术的进步为扩大心理干预的范围和影响以及使干预措施适应个人独特和不断变化的需求提供了巨大的机会。然而,参与不足仍然是数字干预措施有效性的关键障碍。人工交付干预措施(例如,由临床工作人员)可以更吸引人,但可能更昂贵和负担。因此,数字和人类提供的组件的集成对于建立有效和可扩展的心理干预至关重要。现有的实验设计可用于回答有关人类递送组件的问题,这些组件通常以相对较慢的时间尺度进行排序和调整(例如,每月)或关于通常以更快的时间尺度排序和调整的数字组件(例如,daily).然而,这些方法不能在多个时间尺度上适应组件的测序和适应,因此不能用于凭经验告知人工递送和数字组件的联合测序和适应.这里,我们引入了混合实验设计(HED)-一种新的实验方法,可用于回答有关构建心理干预措施的科学问题,在该干预措施中,人工提供和数字组件在多个时间尺度上进行集成和调整。我们描述了HED的关键特征(即,它们是什么),解释他们的科学原理(即,为什么需要它们),并为其设计和相应的数据分析提供指南(即,如何将HED产生的数据用于有效和可扩展的心理干预)。
    Advances in mobile and wireless technologies offer tremendous opportunities for extending the reach and impact of psychological interventions and for adapting interventions to the unique and changing needs of individuals. However, insufficient engagement remains a critical barrier to the effectiveness of digital interventions. Human delivery of interventions (e.g., by clinical staff) can be more engaging but potentially more expensive and burdensome. Hence, the integration of digital and human-delivered components is critical to building effective and scalable psychological interventions. Existing experimental designs can be used to answer questions either about human-delivered components that are typically sequenced and adapted at relatively slow timescales (e.g., monthly) or about digital components that are typically sequenced and adapted at much faster timescales (e.g., daily). However, these methodologies do not accommodate sequencing and adaptation of components at multiple timescales and hence cannot be used to empirically inform the joint sequencing and adaptation of human-delivered and digital components. Here, we introduce the hybrid experimental design (HED)-a new experimental approach that can be used to answer scientific questions about building psychological interventions in which human-delivered and digital components are integrated and adapted at multiple timescales. We describe the key characteristics of HEDs (i.e., what they are), explain their scientific rationale (i.e., why they are needed), and provide guidelines for their design and corresponding data analysis (i.e., how can data arising from HEDs be used to inform effective and scalable psychological interventions).
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  • 文章类型: Journal Article
    多环芳烃(PAHs)和多氯联苯(PCBs)是通常在沉积物中研究的受调节污染物。常规方法通常使用GC-MS以初步提取步骤对其进行分析,这可能是溶剂和耗时的。这里使用实验设计优化了两种提取方法,并比较:微波辅助萃取(MAE)和热解吸(TD);后者很少用于沉积物分析。研究了可能影响提取回收率的几个因素,包括基质参数(质量,有机质(OM)含量)和加工参数。进行了明确的筛选设计DSD,以筛选6个影响最大的因素,并使用TD对提取回收率进行建模。无论OM内容是什么,对于最佳提取,最小沉积物质量(5毫克)更好,最低温度速率(15°Cmin-1),与最小保持时间(5分钟)相关的最高最终温度(350°C),TD单元和低温捕集器之间的最大排气流(150mLmin-1)。此后,使用标准添加评估基质效应,并实施了质量保证和控制,以比较MAE和TD。TD-GC-MS/MS灵敏度高于MAE-GC-MS,对PAHs和PCBs的检出限为5-1160pg和20-125pg,分别。在考虑量化的适当策略时,TD对于沉积物分析也是可靠的。尽管MAE对基质效应不太敏感,TD可以显著改善分析过程,由于与GC-MS/MS直接耦合和完全自动化。此外,TD提供了可能比MAE更高的空间分辨率,特别是对于沉积物岩心分析,由于样本量降低了1000倍。最后,TD-GC-MS/MS表现为更绿色的分析程序。
    Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are regulated contaminants usually investigated in sediments. Conventional approaches often use GC-MS to analyse them with a preliminary extraction step which can be solvent- and time-consuming. Here two extraction methodologies were optimized using experimental designs, and compared: microwave assisted extraction (MAE) and thermal desorption (TD); the latter was rarely used for sediments analyses. Several factors that may influence extraction recoveries were studied including matrix parameters (mass, organic matter (OM) content) and processing parameters. A definitive screening design DSD was performed to screen the 6 most influencing factors and model the extraction recoveries using TD. Whatever the OM content, a minimum sediment mass (5 mg) was better for an optimal extraction, with a minimum temperature rate (15 °C min-1), a maximum final temperature (350 °C) associated with a minimum hold time (5 min), and a maximum vent flow (150 mL min-1) between the TD unit and the cryogenic trap. Thereafter matrix effects were evaluated using standard addition, and quality assurance and control were implemented for comparing MAE and TD. TD-GC-MS/MS sensitivity was higher than MAE-GC-MS with detection limits in the range 5-1160 pg and 20-125 pg for PAHs and PCBs, respectively. When considering the appropriate strategy for quantification, TD was also reliable for sediments analysis. Although MAE was less sensitive to matrix effects, TD could significantly improve the analytical process, due to direct coupling with GC-MS/MS and complete automation. Moreover, TD offered possible higher spatial resolution than MAE, particularly for sediment cores analysis, due to the 1000-times lower sample size. At last, TD-GC-MS/MS appeared as a greener analytical procedure.
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