Automated Sampling System Research Articles

High-frequency data reveal differential dissolved and suspended solids behavior from a mixed restored prairie and agricultural catchment

Quantifying temporal variability and fluxes within hydrologic catchments is critical to understanding the underlying chemical and physical processes leading to material transport. Measuring variability and fluxes requires sampling at time scales similar to the time scale of process occurrence. This demand has led to the development of automated sampling systems designed to sample at high frequencies, on the order of minutes. While widely deployed in a variety of systems, we installed two high-frequency sampling devices in a single drainage comprised of restored prairie and agricultural land uses in temperate Eastern Nebraska. The sampling systems determined flow rate, conductivity, and turbidity at 15-minute intervals for a twelve-month period. Conductivity was used as a proxy for total dissolved solids (TDS) concentrations and turbidity was used as a proxy for total suspended solids (TSS) concentrations. Using the high-frequency data, estimates of solids flux were calculated, error on the estimates was constrained, the effects of sample timing were considered, and conductivity and turbidity changes during precipitation events were examined. Overall, TDS fluxes were about three times higher than TSS fluxes from the catchment as a whole. However, the TSS fluxes were higher in the agricultural section of the catchment than from the restored prairie. Sheet and rill soil loss estimates from both the restored prairie and agricultural settings were low (<0.060 mm/yr). For TDS flux calculations, sampling at a monthly frequency gave a value that was only 11% lower than sampling every 15 min. For TSS flux calculations, sampling only during precipitation events (0.7% of the time) would capture 67% of the annual flux. Thus, minimizing error in sampling strategies depends on the constituent being analyzed.

A Reliable Automated Sampling System for On-Line and Real-Time Monitoring of CHO Cultures

Timely monitoring and control of critical process parameters and product attributes are still the basic tasks in bioprocess development. The current trend of automation and digitization in bioprocess technology targets an improvement of these tasks by reducing human error and increasing through-put. The gaps in such automation procedures are still the sampling procedure, sample preparation, sample transfer to analyzers, and the alignment of process and sample data. In this study, an automated sampling system and the respective data management software were evaluated for system performance; applicability with HPLC for measurement of vitamins, product and amino acids; and applicability with a biochemical analyzer. The focus was especially directed towards the adaptation and assessment of an appropriate amino acid method, as these substances are critical in cell culture processes. Application of automated sampling in a CHO fed-batch revealed its potential with regard to data evaluation. The higher sampling frequency compared to manual sampling increases the generated information content, which allows easier interpretation of the metabolism, extraction of e.g., ks values, application of smoothing algorithms, and more accurate detection of process events. A comparison with sensor technology shows the advantages and disadvantages in terms of measurement errors and measurement frequency.

Reliable chiral recognition with an optoelectronic nose

Chiral discrimination is a key problem in analytical chemistry. It is generally performed using expensive instruments or highly-specific miniaturized sensors. An electronic nose is a bio-inspired instrument capable after training of discriminating a wide variety of analytes. However, generality is achieved at the cost of specificity which makes chiral recognition a challenging task for this kind of device. Recently, a peptide-based optoelectronic nose which can board up to hundreds of different sensing materials has shown promising results, especially in terms of specificity. In line with these results, we describe here its use for chiral recognition. This challenging task requires care, especially in terms of statistical reliability and experimental confounds. For these reasons, we set up an automatic gas sampling system and recorded data over two long sessions, taking care to exclude possible confounds. Two couples of chiral molecules, namely (R) and (S) Limonene and (R) and (S) Carvone, were tested and several statistical analyses indicate the almost perfect discrimination of their two enantiomers. A method to highlight discriminative sensing materials is also proposed and shows that successful discrimination is likely achieved using just a few peptides.

Efficacy of the novel continuous sampling system for PCDD/Fs and unintentional persistent organic pollutants.

Long-term sampling is essential for monitoring the air pollutants emitted from stack since it can monitor the pollutants emission continuously including the stages of start-up, shutdown and normal operation. However, commercial continuous sampling equipment such as AMESA faces the challenges of high weight and complicated sampling procedures. This study has developed a long-term and automatic sampling system (National Central University continuous stack sampling system, NCU-CS3), and compared the efficiency with manual sampling train (MST). The results indicate that relative standard deviation (RSD) of PCDD/Fs concentrations measured between NCU-CS3 and MST is <20%, demonstrating that the difference between NCU-CS3 and MST in measuring PCDD/Fs is insignificant. Besides, the effects of adsorbent temperature, adsorbent amount and type of adsorbent on breakthroughs of PAHs and unintentional-persistent organic pollutants (UPOPs) such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), chlorinated phenols (CPs), chlorinated benzenes (CBs) and polychlorinated naphthalenes (PCNs) are evaluated. The results indicate that the breakthrough of pollutants increases with increasing temperature of XAD-2 and decreases with increasing XAD-2 amount. Moreover, XAD-4 is used as alternative adsorbent to test the breakthrough and the results indicate that the breakthroughs of UPOPs of XAD-4 as adsorbent are lower than that with XAD-2 due to higher specific surface area of XAD-4. Furthermore, the residual of PCDD/Fs with NCU-CS3 as the sampling train is relatively low (1.5-3.8%), which meets the regulation of EN 1948-5 (10%).

Systems of grained materials automated sampling from belt conveyors

Abstract The collection of representative samples of grained materials is necessary to determine the quality parameters of this material. This operation is carried out in difficult conditions (dustiness, noise, atmospheric precipitation), which is a nuisance to the staff taking samples and adversely affects accuracy. In addition, the quality of representative samples is affected by the care of personnel. Therefore, to ensure a higher quality of sampling operations and to eliminate the work of people in difficult conditions, systems have been developed for the automatic collection of representative samples from conveyor belts. The work gives examples of automatic sampling systems equipped with samplers and other auxiliary devices. The work contains descriptions of construction, classifications, an example of selection and examples of construction solutions for automatic sampling of grained materials.

Verification of Automatic Water Sampling System for Chemical Spill Events

Verification of Automatic Water Sampling System for Chemical Spill Events

Design of Micropipette System with High Precision for Small Enzyme Immunoassay Analyzer

A small auto micropipette system is developed to improve the reliability and accuracy of the automatic enzyme immunoassay analyzer’s microscale pipetting system. A sophisticated injection mechanism is designed by the means of dislocation parallel distribution of the screw and injector piston rod. It possesses the function of pipetting, taking and removing the pipette tips. In the control system, STM32 controller is used, controlling the single-axis S-type acceleration/deceleration algorithm and multi-threaded coordinated motion. The acceleration/deceleration curves are analyzed and optimized by using the method of segmentation; a minimum injection rate of 1 μL and a step rate of 0.05 μL are realized. The method of digital image processing is used to detect the amount of pipetting in micro-pipetting quantitatively. The liquid area is extracted by background contrast method, and the liquid volume in the tip is obtained by combining the geometric characteristics of the disposable tip, when the pipetting capacity is not qualified to carry out specific guidance on the pipetting system, and avoid the blocking needle, bubble and other abnormal pipetting phenomenon on the impact of pipetting accuracy. The experimental results show that the combination of the automatic sampling system and the image flow detection system can effectively improve the precision and reliability of the micropipetting system. Finally, the injection accuracy of the system at the test points with 10, 50 and 100 μL liquid volumes reaches 1.8%, 1.28% and 1.15% respectively.

Microliter-ordered automatic blood sampling system for fully quantitative analysis of small-animal PET.

The objective of the present study was to develop a fully automated blood sampling system for kinetic analysis in mice positron emission tomography (PET) studies. Quantitative PET imaging requires radioactivity concentrations in arterial plasma to estimate the behavior of an administered radiopharmaceutical in target organs. Conventional manual blood sampling has several drawbacks, such as the need for troubleshooting in regard to blood collection, necessary personnel, and the radiation exposure dose. We recently developed and verified the operability of a fully automated blood sampling system (automatic blood dispensing system-ABDS). Here, we report the results of fully quantitative measurements of the cerebral metabolic rate of glucose (CMRglc) in mice using the ABDS. Under 1% isoflurane anesthesia, a catheter was inserted into the femoral artery of nine wild-type male mice. Immediately after injection of 18F-fluorodeoxyglucose (FDG) (13.2 ± 3.93MBq in 0.1mL saline), arterial blood samples were drawn using the ABDS and then analyzed using CD-Well, a system we previously developed that can measure radioactivity concentration (Bq/μL) using a few microliters of blood in the plasma and whole blood separately. In total, 16 blood samplings were conducted in 60min as follows: 10s × 9; 70s × 2; 120s × 1; 250s × 1; 10min × 2; and 30min × 1. Dynamic PET scans were conducted concurrently using a small-animal PET/computed tomography (CT) (PET/CT) scanner. Full kinetics modeling using a two-tissue-three-compartment model was applied to calculate CMRglc. Blood volume was also estimated. No significant differences were observed between the manual and ABDS measurements. A proportional error was detected only for plasma. The mean ± standard deviation CMRglc value in the mice was 5.43 ± 1.98mg/100g/min (30.2 ± 11 μmol/min/100g), consistent with a previous report. The automated microliter-ordered blood sampling system developed in the present study appears to be useful for absolute quantification of CMRglc in mice PET studies.

Representative Sampling Implementation in Online VFA/TIC Monitoring for Anaerobic Digestion

This paper describes an automatic sampling system for anaerobic reactors that allows taking representative samples following the guidelines of Gy’s (1998) theory of sampling. Due to the high heterogeneity degree in a digester the sampling errors are larger than the analysis error, making representative sampling a prerequisite for successful process control. In our system, samples are automatically processed, generating a higher density of data and avoiding human error by sample manipulation. The combination of a representative sampling system with a commercial automate titration unit generates a robust online monitoring system for biogas plants. The system was successfully implemented in an operating biogas plant to control a feeding-on-demand biogas system.

Occupational exposure to airborne formaldehyde in hospital: setting an automatic sampling system, comparing different monitoring methods and applying them to assess exposure.

Background:In recent years, under-vacuum sealing (UVS) and containers with formalin encapsulated in the lid have been proposed for the reduction of occupational exposure to airborne formaldehyde (FA) in healthcare environments.Objectives:We are presenting a study focused on the assessment of FA in hospitals: an automatic sampling system was set, different sampling devices were compared, and the concentration of FA was assessed, following its use in different scenarios.Methods:Three different devices for sampling/measuring FA were compared. They are based on: 1. silica gel cartridges impregnated with 2,4-dinitrophenylhydrazine (2,4-DNPH); 2. SPME® fiber using O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine; 3. direct reading commercial instrumentation. Three typical scenarios using FA were investigated: operating theatres where small biopsies are soaked into closed-circuit system 4% FA containers, secretariat of pathology laboratories during the registration of biopsies and pathology laboratories during the filling procedure by UVS and the slicing of biopsies.Results:The automatic sampling system allowed short-, long-, and in continuous-sampling time to measure airborne FA. Different sampling devices provided comparable results when tested to assess FA concentration ranging from 0.020-0.320 ppm in a test chamber, although the devices based on 2,4-DNPH were the best in terms of sensitivity and accuracy. The results of 246 samples showed that the FA concentration was less than 0.04 ppm in 91% of the measurements.Conclusions:The automatic methods efficiently allow sampling and measurement of FA in hospital settings. When using safe practices, the concentration of FA is well below occupational limit values.

Rapid screening of nine illicit drugs in human blood and urine by direct analysis in real-time mass spectrometry

We aimed to establish for the rapid detection of morphine, O6-monoacetylmorphine, heroin, codeine, cocaine, methamphetamine, ketamine, methadone, and dolantin in human blood and urine by direct analysis in real-time coupled with tandem mass spectrometry (DART-MS/MS). These samples were extracted by acetonitrile-methanol (V/V = 4:1), using DART 12 Dip-it automatic sampling system. They were injected at 400°C, and analyzed by positive ion and multiple reaction monitoring mode. The detection limits of morphine, O6-Monoacetylmorphine, heroin, codeine, cocaine, methamphetamine, ketamine, methadone, and dolantin were 100, 50, 50, 100, 20, 20, 10, 1, and 0.01 ng/mL, respectively. The practical cases contained methamphetamine, codeine, cocaine, and O6-monoacetylmorphine were detected accurately and rapidly. The method has the advantages of high sensitivity and good accuracy. The sample processing is simple and can be analyzed in a short time. This method is suitable for the analysis of morphine, O6-monoacetylmorphine, heroin, codeine, cocaine, methamphetamine, ketamine, methadone, and dolantin in some practical cases.

Development of an automated sampling and measurement equipment to determine the greenhouse gas methane on the waterair surface of urban canals

Methane (CH4) emission from the aquatic environment is considered as one of the sources of greenhouse gas contributes significantly important to the global warming. For measuring continuously the methane emission from the water-atmospheric interface an automatic sampling and measurement system using floating chamber integrated methane sensor (Automated Floating Chamber integrated Methane Sensor - AFCMS) has been fabricated including the control and PIC datalogger boards with a lower cost than a commercial product. The floating chamber integrated a methane sensor (Panterra, Neodym Technologies, Canada) which works well not only on the quiet water surface but even on the oscillated one. The sensor (coded 1501-1) has a low LOD = 0.45 ppm and a good linearity (R2 = 0.9947) of methane concentration ranging from 2 to 30 ppm. AFCMS system shows a good performance of the equipment deployment for sampling and measuring the methane emissed from the urban canals.

High-Frequency Water Isotopic Analysis Using an Automatic Water Sampling System in Rice-Based Cropping Systems

High-resolution data on a field scale is very important for improving our understanding of hydrological processes. This is particularly the case for water-demanding agricultural production systems such as rice paddies, for which water-saving strategies need to be developed. Here we report on the application of an in situ, automatic sampling system for high-resolution data on stable isotopes of water (18O and 2H). We investigate multiple rice-based cropping systems consisting of wet rice, dry rice and maize, with a single, but distributed analytical system on a sub-hourly basis. Results show that under dry conditions, there is a clear and distinguishable crop effect on isotopic composition in groundwater. The least evaporative affected groundwater source is that of maize, followed by both rice varieties. Groundwater is primarily a mixture of irrigation and rainwater, where the main driver is irrigation water during the dry season and rainwater during the wet season. Stable isotopes of groundwater under dry season maize react rapidly on irrigation, indicating preferential flow processes via cracks and deep roots. The groundwater during the dry season under wet and dry rice fields is dominated at the beginning of the growing season mainly by the input of rainwater; later, the groundwater is more and more replenished by irrigation water. Overall, based on our data, we estimate significantly higher evaporation (63–77%) during the dry season as compared to the wet season (27–36%). We also find, for the first time, significant sub-daily isotopic variation in groundwater and surface ponded water, with an isotopic enrichment during the daytime. High correlations with relative humidity and temperature, explain part of this variability. Furthermore, the day-night isotopic difference in surface water is driven by the temperature and relative humidity; however, in groundwater, it is neither driven by these factors.

Impact of Squeezing Condition to Obtain Sufficient Blood Volume for Self-Monitoring of Blood Glucose Using an Automatic Puncturing and Sampling System.

Blood sampling for self-monitoring of blood glucose is difficult for the elderly with low dexterity. We developed and tested the utility of an automatic puncturing and sampling (APS) system as a part of an automatic SMBG device, but success rates of securing sufficient blood volume was low (61.9%). Thus, the squeezing condition was changed to increase its success rate. The aim of this study is to investigate the impact to the amount of bleeding by making changes to the squeezing condition. In our previous experiment, blood sampling was performed simultaneously with squeezing, whereas the present study tested blood sampling after squeezing. This method increased the success rate (75%) among eight subjects who had a low success rate (25%) in the previous experiment using the APS system.

Diurnal Patterns of Methane Flux from a Seasonal Wetland: Mechanisms and Methodology

Methane emissions from wetlands are temporally dynamic. Few chamber-based studies have explored diurnal variation in methane flux with high temporal replication. Using an automated sampling system, we measured methane flux every 2.5 to 4 h for 205 diel cycles during three growing seasons (2013–2015) from a seasonal wetland in the Prairie Pothole Region of North America. During ponded conditions, fluxes were generally positive (i.e., methanogenesis dominant, 10.1 ± 0.8 mg m−2 h−1), had extreme range of variation (from −1 to 70 mg m−2 h−1), and were highest during late day. In contrast, during dry conditions fluxes were very low and primarily negative (i.e., oxidation dominant, −0.05 ± 0.002 mg m−2 h−1), with the highest (least negative) fluxes occurring at pre-dawn. During semi-saturated conditions, methane fluxes also were very low, oscillated between positive and negative values (i.e., balanced between methanogenesis and methane oxidation), and exhibited no diel pattern. Methane flux was positively correlated with air temperature during ponded conditions (r = 0.57) and negatively during dry conditions (r = −0.42). Multiple regression analyses showed that temperature, light and water-filled pore space explained 72% of variation in methane flux. Methane fluxes are highly temporally dynamic and follow contrasting diel patterns that are dependent on dominant microbial processes influenced by saturation state.

Monoterpene chemical speciation in a tropical rainforest:variation with season, height, and time of dayat the Amazon Tall Tower Observatory (ATTO)

Abstract. Speciated monoterpene measurements in rainforest air are scarce, but they are essential for understanding the contribution of these compounds to the overall reactivity of volatile organic compound (VOC) emissions towards the main atmospheric oxidants, such as hydroxyl radicals (OH), ozone (O3) and nitrate radicals (NO3). In this study, we present the chemical speciation of gas-phase monoterpenes measured in the tropical rainforest at the Amazon Tall Tower Observatory (ATTO, Amazonas, Brazil). Samples of VOCs were collected by two automated sampling systems positioned on a tower at 12 and 24 m height and analysed using gas chromatography–flame ionization detection. The samples were collected in October 2015, representing the dry season, and compared with previous wet and dry season studies at the site. In addition, vertical profile measurements (at 12 and 24 m) of total monoterpene mixing ratios were made using proton-transfer-reaction mass spectrometry. The results showed a distinctly different chemical speciation between day and night. For instance, α-pinene was more abundant during the day, whereas limonene was more abundant at night. Reactivity calculations showed that higher abundance does not generally imply higher reactivity. Furthermore, inter- and intra-annual results demonstrate similar chemodiversity during the dry seasons analysed. Simulations with a canopy exchange modelling system show simulated monoterpene mixing ratios that compare relatively well with the observed mixing ratios but also indicate the necessity of more experiments to enhance our understanding of in-canopy sinks of these compounds.

Measuring water content of pressed beet pulp – Microwave transmission measurement for process optimization and quality improvement

In the 2016 campaign, the Aarberg sugar factory of Schweizer Zucker AG successfully installed and operated a microwave based water content measurement system at the discharge line of the pressed beet pulp aiming for improved availability and reliability of dry substance value allowing a more precise adjustment of water content within contract specifications. For optimum performance, calibration and verification of the measurement results an automated sampling system has been introduced. Within this article the measurement results are presented and compared to laboratory analysis. The improvements achieved on pressed pulp processing in comparison to current methods as well as the sampling setup and the suitability of microwave transmission technology for this measurement task in general are discussed.

Development of an Automatic Puncturing and Sampling System for a Self-Monitoring Blood Glucose Device.

Performing self-monitoring of blood glucose (SMBG) is a clinical challenge for elderly people with low dexterity. An all-in-one-type SMBG device that can simply and easily puncture and monitor would be useful for them. We developed an automatic skin-puncturing and blood-sampling (APS) system for introducing of an all-in-one-type SMBG device. The aims of this study were to determine if the developed APS system, which has automatic puncturing, squeezing, and application functions, could provide sufficient blood sample volumes for SMBG and to determine the factors associated with failure in the use of the system by adult volunteers. We investigated the success rate of obtaining a 0.8-μL sample volume using the APS system and determined the factors associated with failure in 140 adult volunteers. The participant characteristics, induration of puncturing sites, and states of finger grip conditions were evaluated as factors of a puncturing failure. The participant characteristics, skin hydration, states of finger grip, skin elasticity of the finger pad, and blood flow were evaluated as factors of a squeezing failure. The success rate was 61.9%. Puncturing failure was 21.6%, and squeezing failure was 16.5%. Automatic puncturing factors associated with failure were male sex, larger finger diameter, and thicker finger pad. The only squeezing failure factor was lower peripheral skin temperature. Improvement of the finger station groove shape to prevent ischemia and the squeezing angle would be useful developments of the all-in-one-type SMBG device for elderly people with decreased dexterity.

PTR-ToF-MS Coupled with an Automated Sampling System and Tailored Data Analysis for Food Studies: Bioprocess Monitoring, Screening and Nose-space Analysis.

Proton Transfer Reaction (PTR), combined with a Time-of-Flight (ToF) Mass Spectrometer (MS) is an analytical approach based on chemical ionization that belongs to the Direct-Injection Mass Spectrometric (DIMS) technologies. These techniques allow the rapid determination of volatile organic compounds (VOCs), assuring high sensitivity and accuracy. In general, PTR-MS requires neither sample preparation nor sample destruction, allowing real time and non-invasive analysis of samples. PTR-MS are exploited in many fields, from environmental and atmospheric chemistry to medical and biological sciences. More recently, we developed a methodology based on coupling PTR-ToF-MS with an automated sampler and tailored data analysis tools, to increase the degree of automation and, consequently, to enhance the potential of the technique. This approach allowed us to monitor bioprocesses (e.g. enzymatic oxidation, alcoholic fermentation), to screen large sample sets (e.g. different origins, entire germoplasms) and to analyze several experimental modes (e.g. different concentrations of a given ingredient, different intensities of a specific technological parameter) in terms of VOC content. Here, we report the experimental protocols exemplifying different possible applications of our methodology: i.e. the detection of VOCs released during lactic acid fermentation of yogurt (on-line bioprocess monitoring), the monitoring of VOCs associated with different apple cultivars (large-scale screening), and the in vivo study of retronasal VOC release during coffee drinking (nosespace analysis).

PTR-ToF-MS Coupled with an Automated Sampling System and Tailored Data Analysis for Food Studies: Bioprocess Monitoring, Screening and Nose-space Analysis

Proton Transfer Reaction (PTR), combined with a Time-of-Flight (ToF) Mass Spectrometer (MS) is an analytical approach based on chemical ionization that belongs to the Direct-Injection Mass Spectrometric (DIMS) technologies. These techniques allow the rapid determination of volatile organic compounds (VOCs), assuring high sensitivity and accuracy. In general, PTR-MS requires neither sample preparation nor sample destruction, allowing real time and non-invasive analysis of samples. PTR-MS are exploited in many fields, from environmental and atmospheric chemistry to medical and biological sciences. More recently, we developed a methodology based on coupling PTR-ToF-MS with an automated sampler and tailored data analysis tools, to increase the degree of automation and, consequently, to enhance the potential of the technique. This approach allowed us to monitor bioprocesses (e.g. enzymatic oxidation, alcoholic fermentation), to screen large sample sets (e.g. different origins, entire germoplasms) and to analyze several experimental modes (e.g. different concentrations of a given ingredient, different intensities of a specific technological parameter) in terms of VOC content. Here, we report the experimental protocols exemplifying different possible applications of our methodology: i.e. the detection of VOCs released during lactic acid fermentation of yogurt (on-line bioprocess monitoring), the monitoring of VOCs associated with different apple cultivars (large-scale screening), and the in vivo study of retronasal VOC release during coffee drinking (nosespace analysis).