Experimentally validated mathematical model of analyte uptake by permeation passive samplers

2017 ◽  
Vol 19 (11) ◽  
pp. 1363-1373 ◽  
Author(s):  
F. Salim ◽  
M. Ioannidis ◽  
T. Górecki
Keyword(s):  
Mathematical Model ◽  
Passive Sampler ◽  
Passive Samplers ◽  
Sampling Process

A mathematical model describing the sampling process in a permeation-based passive sampler was developed and evaluated numerically.

Modelling permeation passive sampling: intra-particle resistance to mass transfer and comprehensive sensitivity analysis

2019 ◽  
Vol 21 (3) ◽  
pp. 469-484 ◽  
Author(s):  
Faten Salim ◽  
Marios Ioannidis ◽  
Alexander Penlidis ◽  
Tadeusz Górecki
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Sensitivity Analysis ◽  
Passive Sampling ◽  
Passive Samplers ◽  
Porous Particles ◽  
Sampling Process ◽  
Porous Adsorbents

A mathematical model developed previously to describe the sampling process in permeation passive samplers with non-porous adsorbents and evaluated using the Waterloo Membrane Sampler (WMS) is here extended to include adsorbents with porous particles.

scholarly journals Development of passive sampler POCIS for the analysis of polar pesticides in surface water

2015 ◽  
Vol 18 (2) ◽  
pp. 132-144
Author(s):  
Trang Thi Nhu Tran ◽  
Ty Thi Pham ◽  
Hai Lam Son Truong
Keyword(s):  
Surface Water ◽  
Environmental Factors ◽  
Pesticide Residues ◽  
Passive Sampling ◽  
Sampling Method ◽  
Passive Sampler ◽  
Polar Pesticides ◽  
Sampling Process ◽  
European Standards ◽  
First Time

The first time in Vietnam a passive sampling method has been developed to analyse the polar pesticides in surface water. The initial investigations of POCIS were performed for 7 polar pesticides as simazine,thiodicarb, carbofuran, chlortoluron, atrazine, isoproturon, and diuron. We determined the sampling rates RS for these substances ranged from 0.369 to 0.962 L day- 1. The obtained values of ku and RS showed the important influence of environmental factors such as flow on the ability to integrate polar pesticides in passive sampling process. This method can be applied to determine these 7 polar pesticides in surface water at trace levels according to European standards for pesticide residues in water (< 0.1 μg L-1).

scholarly journals Relationships between Passive Sampler and Continuous Ozone (O3) Measurement Data in Ecological Effects Research

2001 ◽  
Vol 1 ◽  
pp. 593-601 ◽  
Author(s):  
S. Krupa ◽  
M. Nosal
Keyword(s):  
Continuous Monitoring ◽  
Passive Sampling ◽  
Passive Sampler ◽  
Ecological Effects ◽  
Passive Samplers ◽  
Cumulative Exposure ◽  
Generic Model ◽  
Monitoring Site ◽  
Frequency Distributions ◽  
Continuous Monitor

In ecological effects research, there is a rapid increase in the application of passive sampling techniques for measuring ambient ozone (O3) concentrations. Passive samplers provide data on cumulative exposures of a plant to a pollutant. However, O3is not an accumulative contaminant within the plant tissue, and use of prolonged passive sampling durations cannot account for the dynamics of the occurrences of O3that have a significant influence on the plant response. Therefore, a stochastic Weibull probability model was previously developed and applied to a site in Washington State (1650 m MSL) to simulate the cumulative exposure data from a passive sampler, to mimic the corresponding frequency distributions of hourly O3concentrations that would otherwise have been obtained by continuous monitoring. At that site the correlation between the actual passive sampler and the continuous monitor data was R2 = 0.74. The simulation of the hourly O3data was based on and compared with the results obtained from a colocated continuous monitor. In this paper we report the results of the model application to data from an unrelated monitoring site (New Hampshire, 476 m MSL) with poor correlation between the passive sampling and continuous monitoring (R2 = 0.24). In addition, as opposed to the previous work, we provide comparisons of the frequency distributions of the hourly O3concentrations obtained by the simulation and the actual continuous monitoring. In spite of the major difference in the R2 values, at both sites the simulation provided very satisfactory results within the 95% confidence interval, suggesting its broad applicability. The final objective of this overall approach is to develop a generic model that can simulate reasonably well the occurrences of ambient O3concentrations that are dependent upon the elevation of the measurement site and the synoptic and local meteorology. Such an effort would extend the relative utility of the passive sampling data in explaining stochastic plant responses.

scholarly journals A Unique Interactive Nanostructure Knitting based Passive Sampler Adsorbent for Monitoring of Hg2+ in Water

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3432 ◽  
Author(s):  
Raghuraj S. Chouhan ◽  
Gregor Žitko ◽  
Vesna Fajon ◽  
Igor Živković ◽  
Majda Pavlin ◽  
...  
Keyword(s):  
Low Cost ◽  
Passive Sampler ◽  
Passive Samplers ◽  
Adsorption Efficiency ◽  
Sensor Applications ◽  
High Temperature Short Time ◽  
Green Adsorbent ◽  
Polycondensation Process ◽  
Quality Water ◽  
Short Time

This work reports the development of ultralight interwoven ultrathin graphitic carbon nitride (g-CN) nanosheets for use as a potential adsorbent in a passive sampler (PAS) designed to bind Hg2+ ions. The g-CN nanosheets were prepared from bulk g-CN synthesised via a modified high-temperature short-time (HTST) polycondensation process. The crystal structure, surface functional groups, and morphology of the g-CN nanosheets were characterised using a battery of instruments. The results confirmed that the as-synthesized product is composed of few-layered nanosheets. The adsorption efficiency of g-CN for binding Hg2+ (100 ng mL−1) in sea, river, rain, and Milli-Q quality water was 89%, 93%, 97%, and 100%, respectively, at natural pH. Interference studies found that the cations tested (Co2+, Ca2+, Zn2+, Fe2+, Mn2+, Ni2+, Bi3+, Na+, and K+) had no significant effect on the adsorption efficiency of Hg2+. Different parameters were optimised to improve the performance of g-CN such as pH, contact time, and amount of adsorbent. Optimum conditions were pH 7, 120 min incubation time and 10 mg of nanosheets. The yield of nanosheets was 72.5%, which is higher compared to other polycondensation processes using different monomers. The g-CN sheets could also be regenerated up to eight times with only a 20% loss in binding efficiency. Overall, nano-knitted g-CN is a promising low-cost green adsorbent for use in passive samplers or as a transducing material in sensor applications.

Effect of the orientation and fluid flow on the accumulation of organotin compounds to Chemcatcher passive samplers

2015 ◽  
Vol 17 (4) ◽  
pp. 813-824 ◽  
Author(s):  
H. Ahkola ◽  
J. Juntunen ◽  
M. Laitinen ◽  
K. Krogerus ◽  
T. Huttula ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Environmental Conditions ◽  
Passive Sampling ◽  
Passive Samplers ◽  
Organotin Compounds ◽  
Environmental Legislation ◽  
Sampling Process

The effect of environmental conditions on the passive sampling process should be understood to estimate the concentration of chemical required by environmental legislation.

scholarly journals Efficient duplicate rate estimation from subsamples of sequencing libraries

2015 ◽  
Author(s):  
Christopher Schröder ◽  
Sven Rahmann
Keyword(s):  
Mathematical Model ◽  
Quality Control ◽  
High Throughput Sequencing ◽  
Linear Optimization ◽  
Computational Approach ◽  
Mathematical Framework ◽  
Quality Metric ◽  
Sampling Process ◽  
Copy Numbers ◽  
Occupancy Distribution

In high-throughput sequencing (HTS) projects, the sequenced fragments’ duplicate rate is a key quality metric. A high duplicate rate may arise from a low amount of input DNA and many PCR cycles. Many methods for downstream analyses require that duplicates be removed. If the duplicate rate is high, most of the sequencing effort and money spent would have been in vain. Therefore, it is of considerable interest to estimate the duplicate rate after sequencing only a small subsample at low depth (multiplexed with other libraries) for quality control before running the full experiment. In this article, we provide an elementary mathematical framework and an efficient computational approach based on quadratic and linear optimization to estimate the true duplicate rate from a small subsample. Our method is based on up-sampling the occupancy distribution of the reads’ copy numbers. Compared to an existing approach, we use an explicit and easily explained mathematical model that accurately inverts the sub-sampling process. We evaluate the performance of our approach in comparison to that of the existing method on several artificial and real datasets. The same ideas can be used for diversity estimation in general. Software implementing our approach is available under the MIT license.

scholarly journals OZONE CONCENTRATION VARIATIONS NEAR HIGH‐VOLTAGE TRANSMISSION LINES/OZONO KONCENTRACIJOS KITIMAS TIES AUKŠTOSIOS ĮTAMPOS TIEKIMO LINIJOMIS/ИЗМЕНЕНИЯ КОНЦЕНТРАЦИИ ОЗОНА ВБЛИЗИ ВЫСОКОВОЛЬТНЫХ ЛИНИЙ ЭЛЕКТРОПЕРЕДАЧ

2009 ◽  
Vol 17 (1) ◽  
pp. 28-35 ◽  
Author(s):  
Vaida Valuntaitė ◽  
Vaida Šerevičienė ◽  
Raselė Girgždienė
Keyword(s):  
High Voltage ◽  
Ozone Concentration ◽  
Transmission Lines ◽  
Passive Sampler ◽  
Passive Samplers ◽  
Real Concentration ◽  
Concentration Changes ◽  
High Voltage Transmission ◽  
The Difference ◽  
The Impact

Changes and distribution of ozone concentration in the area of high‐voltage transmission lines were investigated. The investigation on ozone concentration changes was performed with application of two methods: by using an ozone analyser and by passive samplers. The role of an accumulating element was performed by a glass‐fiber filter installed in a passive sampler. It was impregnated with a 1.2‐di(4‐pyridyl)ethylene and acetate acid solution. The impact of meteorological parameters on the passive sampler efficiency and ozone concentration variation is discussed. These parameters can increase or decrease the real concentration value in comparison with the concentration obtained by co‐located continuously running ozone analyser. Ozone concentration near high‐voltage lines varied from 10 to 51 ppb, and “background” ozone concentration changed from 3 to 50 ppb during the investigation period. The average concentrations were 28.1 and 27.5 ppb near the lines and “background” during the whole experiment period. The wind direction from “background” location to the high‐voltage lines prevailed during the experiment. The obtained results by different methods demonstrated good agreement; the difference between ozone concentrations was from 1 to 24% for individual cases. Santrauka Tirta ozono koncentracijos kitimas ir pasiskirstymas ties aukštosios įtampos perdavimo linijomis. Ozono koncentracija matuota dviem metodais – ozono analizatoriumi ir pasyviaisiais kaupikliais. Pasyviajame kaupiklyje kaip kaupiantysis elementas buvo naudojamas stiklo pluošto filtras, impregnuotas 1,2-di(4-pyridyl)etileno ir acetatinės rūgšties tirpalu. Vėjo greitis, vėjo kryptis, UV spinduliuotė, temperatūra ir santykinė oro drėgmė gali turėti įtakos pasyviųjų kaupiklių efektyvumui bei ozono koncentracijos pasiskirstymui, todėl kartu tirti ir meteorologiniai parametrai (temperatūra, santykinė oro drėgmė, vėjo greitis ir kryptis). Tyrimo laikotarpiu ozono koncentracija ties aukštosios įtampos tiekimo linijomis kito nuo 10 iki 51 ppb, o nutolusioje per 222 m vietovėje, kuri buvo traktuojama kaip foninė, – nuo 3 iki 50 ppb. Išmatuota vidutinė ozono koncentracija foninėje vietoje buvo 27,5 ppb, o ties linijomis – 28,1 ppb. Eksperimento metu vyravo pietryčių krypties vėjas, t. y. nuo foninės vietos – aukštosios įtampos tiekimo linijų link. Nustatant ozono koncentraciją skirtingais metodais duomenys pakankamai sutapo, pavieniais atvejais nesutapimas svyravo nuo 1 iki 24 %. Резюме Исследовалось изменение и распределение концентрации озона в районе высоковольтных линий электропередач. Концентрация озона измерялась двумя методами: анализаторами озона УФ-поглощения непрерывного действия и с использованием пассивных сорбентов. В качестве сорбента использовался фильтр из стекловолокна, пропитанный 1,2-ди(4-пиридил)этиленом и уксусной кислотой. Параллельно непрерывно измерялась температура и относительная влажность воздуха, скорость и направление ветра. Исследования показали, что концентрация озона в течение эксперимента изменялась в интервале от 10 до 51 ррb у линии и от 3 до 50 ррb на «фоновой» точке, удаленной от линий электропередач на расстояние 222 м. В течение эксперимента почти половину времени преобладал боковой ветер по отношению к высоковольтным линиям со стороны фоновой точки. Средние измеренные концентрации озона составляли 27,5 ррb на «фоновой» точке и 28,1 ррb – у линий. Результаты измерения концентрации озона как анализаторами непрерывного действия, так и по методике с использованием пассивных сорбентов показали хорошее совпадение: разница составляла 2–15% и лишь в отдельных случаях 24%.

scholarly journals Passive Sampler for Measurements of Atmospheric Nitric Acid Vapor (HNO3) Concentrations

2001 ◽  
Vol 1 ◽  
pp. 815-822 ◽  
Author(s):  
Andrzej Bytnerowicz ◽  
Pamela E. Padgett ◽  
Michael J. Arbaugh ◽  
David R. Parker ◽  
David P. Jones
Keyword(s):  
Nitric Acid ◽  
Passive Sampler ◽  
Air Pollutant ◽  
Passive Samplers ◽  
Usda Forest Service ◽  
Acid Vapor ◽  
San Bernardino Mountains ◽  
San Bernardino ◽  
Direct Injury ◽  
Annular Denuder

Nitric acid (HNO3) vapor is an important nitrogenous air pollutant responsible for increasing saturation of forests with nitrogen and direct injury to plants. The USDA Forest Service and University of California researchers have developed a simple and inexpensive passive sampler for monitoring air concentrations of HNO3. Nitric acid is selectively absorbed on 47-mm Nylasorb nylon filters with no interference from particulate NO3-. Concentrations determined with the passive samplers closely corresponded with those measured with the co-located honeycomb annular denuder systems. The PVC protective caps of standardized dimensions protect nylon filters from rain and wind and allow for reliable measurements of ambient HNO3concentrations. The described samplers have been successfully used in Sequoia National Park, the San Bernardino Mountains, and on Mammoth Mountain in California.

scholarly journals Efficient duplicate rate estimation from subsamples of sequencing libraries

2015 ◽  
Author(s):  
Christopher Schröder ◽  
Sven Rahmann
Keyword(s):  
Mathematical Model ◽  
Quality Control ◽  
High Throughput Sequencing ◽  
Linear Optimization ◽  
Computational Approach ◽  
Mathematical Framework ◽  
Quality Metric ◽  
Sampling Process ◽  
Copy Numbers ◽  
Occupancy Distribution

In high-throughput sequencing (HTS) projects, the sequenced fragments’ duplicate rate is a key quality metric. A high duplicate rate may arise from a low amount of input DNA and many PCR cycles. Many methods for downstream analyses require that duplicates be removed. If the duplicate rate is high, most of the sequencing effort and money spent would have been in vain. Therefore, it is of considerable interest to estimate the duplicate rate after sequencing only a small subsample at low depth (multiplexed with other libraries) for quality control before running the full experiment. In this article, we provide an elementary mathematical framework and an efficient computational approach based on quadratic and linear optimization to estimate the true duplicate rate from a small subsample. Our method is based on up-sampling the occupancy distribution of the reads’ copy numbers. Compared to an existing approach, we use an explicit and easily explained mathematical model that accurately inverts the sub-sampling process. We evaluate the performance of our approach in comparison to that of the existing method on several artificial and real datasets. The same ideas can be used for diversity estimation in general. Software implementing our approach is available under the MIT license.

scholarly journals Development of a highly sensitive sampler for atmospheric monitoring of 8-H ambient ozone concentrations

2020 ◽  
Vol 25 (6) ◽  
pp. 938-945
Author(s):  
Gülnihal KARA
Keyword(s):  
Urban Areas ◽  
Sampling Rate ◽  
Composite Membranes ◽  
Ambient Air ◽  
Absorption Capacity ◽  
Passive Sampler ◽  
Passive Samplers ◽  
Winter Period ◽  
Highly Sensitive ◽  
Measurement Results

A new passive sampler reinforced with a composite membrane was developed to determine the 8-h ozone (O3) concentration in ambient air. The composite membrane's water absorption capacity and porosity values were found analyzing its surface morphology using Scanning Electron Microscopy (SEM).Ozone adsorption performance of this sampler was tested by a badge-type sampler and automated measurement results. The developed sampler gave results equivalent (R<sup>2</sup> = 0.85) to those of automated O3 monitors, and its experimental sampling rate was determined to be 55 cm<sup>3</sup>/min, approximately two times higher than the rate of the badge-type sampler. The detection limit obtained (5.3 μg/m<sup>3<.sup>, 8 h sampling) in the study was adequate for winter-period samplings where in the ozone concentration is low in urban and semi-urban areas. Multimedia sampling results revealed that the results of the developed passive sampler had a high repeatability (RSD < 20%). Passive samplers reinforced with composite membranes were tested by badge-type samplers performing simultaneous samplings in land conditions. Area sampling results indicated that badge-type samplers were not suitable for 8-h area samplings, but tube-type samplers could be used.

Sign in / Sign up

Export Citation Format

Share Document