Bench-top Analyzer Research Articles

Accelerating fragment-based library generation by coupling high-performance photoreactors with benchtop analysis.

Herein we report a workflow coupling photoredox-nickel dual-catalyzed N-arylation reactions to benchtop analysis for the efficient generation of fragment-based libraries. Technological advances in photoreactor design facilitated reliable and reproducible experimentation. Knowledge on the reactivity under previously reported reaction conditions of spirocyclic and strained heterocyclic building blocks, viewed as chemistry informers, could thus be rapidly accessed, identifying privileged or challenging scaffolds and paving the way for further exploration.

Evaluation of the Element point-of-care blood gas analyzer for use in horses.

To compare the Element point-of-care (POC) portable blood gas analyzer with a laboratory-based bench-top reference analyzer using whole blood samples obtained from horses presenting to a referral center with various disorders in order to determine agreement between these analyzers. Prospective clinical study. The study was conducted at a university teaching hospital at moderate altitude. One hundred paired samples from 80 horses>1 year of age were collected after obtaining informed client consent. Fifty paired samples were from patients admitted for elective procedures and considered to be healthy, and 50 paired samples were emergency admissions and considered to be critically ill. Paired whole blood samples were evaluated on both the Element POC and Radiometer ABL 800 FLEX analyzers simultaneously, and results were compared. Pearson correlation coefficients between analyzers were calculated. To assess agreement, scatter and Bland-Altman plots were evaluated, and mean difference and 95% limits of agreement were calculated for each analyte. Correlation was either good (0.8-0.92) or excellent (>0.93) for the majority of analytes. All analytes apart from hemoglobin had acceptable agreement, with≥80% of individual results within agreement targets. Precision targets were acceptable for most analytes, with partial pressure of carbon dioxide (pCO2 ) and calcium (Ca2+ ) exceeding precision targets. The portable Element POC system had acceptable agreement with the ABL 800 FLEX bench-top analyzer currently in use at the study center when evaluating the majority of analytes from equine whole blood samples.

Intelligent Ultrasonic Energy: New Adaptive Tissue Technology in Harmonic Shears

<i>Objective</i>: Development of ultrasonic technology in surgical devices includes mechanisms of monitoring and adjusting energy delivery to target tissues for the purpose of limiting thermal spread. The objective of the current study was to evaluate performance of a new Adaptive Tissue Technology algorithm, designed to enhance thermal management in the HARMONIC 1100 Shears. <i>Methods</i>: The HARMONIC 1100 Shears were evaluated with bench-top and <i>in vivo</i> preclinical (porcine) analyses for tissue thermal spread, blade heat, transection speed, hemostasis and vessel sealing performance. Testing was performed in parallel with the current production HARMONIC HD 1000i Shears to confirm non-inferiority of the new Adaptive Tissue Technology algorithm. <i>Results</i>: Bench top analysis revealed significantly lower average maximum blade temperatures for HARMONIC 1100 compared to HARMONIC HD 1000i as well as HARMONIC ACE+ 7 Shears with Advanced Hemostasis. Thermal spread, transection speeds, and burst pressure tests of excised porcine carotid arteries did not show a statistical difference between HARMONIC 1100 and HD 1000iShears. <i>In vivo</i> analysis of hemostasis following sealing/transection of various blood vessels in acute porcine testing demonstrated similar efficacy for HARMONIC 1100 and HD 1000i Shears. Likewise, tissue lateral thermal damage showed no statistical difference between the new and previous generation Harmonic device in the porcine model. <i>Conclusion</i>: The new Adaptive Tissue Technology in HARMONIC 1100 Shears allows for reduced maximum blade temperatures while providing effective hemostasis, sealing strength, transection speed, and limited thermal damage.

Soft, skin-interfaced microfluidic systems with integrated enzymatic assays for measuring the concentration of ammonia and ethanol in sweat.

Eccrine sweat is a rich and largely unexplored biofluid that contains a range of important biomarkers, from electrolytes, metabolites, micronutrients and hormones to exogenous agents, each of which can change in concentration with diet, stress level, hydration status and physiologic or metabolic state. Traditionally, clinicians and researchers have used absorbent pads and benchtop analyzers to collect and analyze the biochemical constituents of sweat in controlled, laboratory settings. Recently reported wearable microfluidic and electrochemical sensing devices represent significant advances in this context, with capabilities for rapid, in situ evaluations, in many cases with improved repeatability and accuracy. A limitation is that assays performed in these platforms offer limited control of reaction kinetics and mixing of different reagents and samples. Here, we present a multi-layered microfluidic device platform with designs that eliminate these constraints, to enable integrated enzymatic assays with demonstrations of in situ analysis of the concentrations of ammonia and ethanol in microliter volumes of sweat. Careful characterization of the reaction kinetics and their optimization using statistical techniques yield robust analysis protocols. Human subject studies with sweat initiated by warm-water bathing highlight the operational features of these systems.

Molecular Barcoding as a Defense Against Benchtop Biochemical Attacks on DNA Fingerprinting and Information Forensics

DNA fingerprinting can offer remarkable benefits, especially for point-of-care diagnostics, information forensics, and analysis. However, the pressure to drive down costs is likely to lead to cheap untrusted solutions and a multitude of unprecedented risks. These risks will especially emerge at the frontier between the cyberspace and DNA biology. To address these risks, we perform a forensic-security assessment of a typical DNA-fingerprinting flow. We demonstrate, for the first time, benchtop analysis of biochemical-level vulnerabilities in flows that are based on a standard quantification assay known as polymerase chain reaction (PCR) . After identifying potential vulnerabilities, we realize attacks using benchtop techniques to demonstrate their catastrophic impact on the outcome of the DNA fingerprinting. We also propose a countermeasure, in which DNA samples are each uniquely barcoded (using synthesized DNA molecules) in advance of PCR analysis, thus demonstrating the feasibility of our approach using benchtop techniques. We discuss how molecular barcoding could be utilized within a cyber-biological framework to improve DNA-fingerprinting security against a wide range of threats, including sample forgery. We also present a security analysis of the DNA barcoding mechanism from a molecular biology perspective.

A novel two-dimensional NMR relaxometry pulse sequence for petrophysical characterization of shale at low field.

Low field two-dimensional nuclear magnetic resonance (2D-NMR) relaxometry is a powerful probe for the characterization of heterogenous, porous media and provides geometrical, physical and chemical information about samples at a molecular level and has been widely used in shale studies. However, NMR signals of shale decay so rapidly, dry sample for particular, that the conventional two-dimensional pulse sequence is either not sensitive enough to short relaxation components or takes too much measurement time. In this paper, 2D-NMR relaxometry correlation based on partial inversion recovery CPMG (PIR-CPMG) pulse sequence is proposed and illustrated to improve the contrast over saturation recovery CPMG (SR-CPMG) and reduces the T1 encoding time of inversion recovery CPMG (IR-CPMG) for petrophysical characterization of shale. Subsequently, the kernel function and inversion method of this sequence are presented and the reliability of the inversion method is testified by numerical simulation. Next, theoretical analysis is conducted to validate the advantages of PIR-CPMG. Ultimately, experiments on copper sulfate solution, artificial sandstone, and shale samples are performed, respectively, to verify the feasibility and effectiveness of the proposed pulse sequence. The results demonstrate that the PIR-CPMG sequence is time-saving and high-contrast, especially for the short relaxation components. This pulse sequence can be utilized in bench-top NMR core analyzer and downhole well logging, potentially, to achieve integrated petrophysical characterization of shale.

ENose analysis of volatile chemicals from dogs naturally infected with Leishmania infantum in Brazil.

BackgroundVisceral leishmaniasis (VL) in Brazil is a neglected, vector-borne, tropical parasitic disease that is responsible for several thousand human deaths every year. The transmission route involves sand flies becoming infected after feeding on infected reservoir host, mainly dogs, and then transmitting the Leishmania infantum parasites while feeding on humans. A major component of the VL control effort is the identification and euthanasia of infected dogs to remove them as a source of infection. A rapid, non-invasive, point-of-care device able to differentiate between the odours of infected and uninfected dogs may contribute towards the accurate diagnosis of canine VL.Methodology/Principal findingsWe analysed the headspace volatile chemicals from the hair of two groups of dogs collected in 2017 and 2018 using a bench-top eNose volatile organic chemical analyser. The dogs were categorised as infected or uninfected by PCR analysis of blood samples taken by venepuncture and the number of parasites per ml of blood was calculated for each dog by qPCR analysis. We demonstrated using a robust clustering analysis that the eNose data could be discriminated into infected and uninfected categories with specificity >94% and sensitivity >97%. The eNose device and data analysis were sufficiently sensitive to be able to identify infected dogs even when the Leishmania population in the circulating blood was very low.Conclusions/SignificanceThe study illustrates the potential of the eNose to rapidly and accurately identify dogs infected with Le. infantum. Future improvements to eNose analyser sensor sensitivity, sampling methodology and portability suggest that this approach could significantly improve the diagnosis of VL infected dogs in Brazil with additional potential for effective diagnosis of VL in humans as well as for the diagnosis of other parasitic diseases.

Precision and Limits of Detection for Selected Commercially Available, Low-Cost Carbon Dioxide and Methane Gas Sensors.

The performance of a sensor platform for environmental or industrial monitoring is sensitive to the cost and performance of the individual sensor elements. Thus, the detection limits, accuracy, and precision of commercially available, low-cost carbon dioxide and methane gas concentration sensors were evaluated by precise measurements at known gas concentrations. Sensors were selected based on market availability, cost, power consumption, detection range, and accuracy. A specially constructed gas mixing chamber, coupled to a precision bench-top analyzer, was used to characterize each sensor during a controlled exposure to known gas concentrations. For environmental monitoring, the selected carbon dioxide sensors were characterized around 400 ppm. For methane, the sensor response was first monitored at 0 ppm, close to the typical environmental background. The selected sensors were then evaluated at gas concentrations of several thousand ppm. The determined detection limits accuracy, and precision provides a set of matrices that can be used to evaluate and select sensors for integration into a sensor platform for specific applications.

Benchtop NMR Spectroscopy and Spectral Analysis of the cis- and trans-Stilbene Products of the Wittig Reaction

ABSTRACT: Benchtop NMR spectrometers are now becoming more widely employed in university teaching laboratories. These low-field instruments are increasingly used in reaction monitoring and product purity applications. NMR spectra obtained using these spectrometers (40−80 MHz) tend to suffer from significant overlap of signals when compared to those obtained at 300−400 MHz or above, and therefore, some reactions may be less suited to analysis using such benchtop systems. While some reactions can be modified to make them more amenable to analysis on low-field benchtop spectrometers, the fact remains that many common undergraduate laboratory chemistry reactions remain as a stalwart of the university education system. Therefore, there is currently a major requirement for benchtop NMR analysis to improve in order to facilitate student understanding. Herein, it is demonstrated that a combination of spectral analysis and simulation at low-fields (40−80 MHz) allows the fine structure of second-order effects and overlapping spectra to be deduced, enabling an improved understanding of the low-field benchtop NMR technique within undergraduate student cohorts. The evolution of well-resolved and distinct multiplets at 400 MHz to complex, overlapping multiplets at 40−80 MHz also serves as a useful guide for laboratory demonstrators and academic staff when explaining the advantages of such benchtop systems. The Wittig reaction has been a standard reaction practical session in many university teaching laboratories since the 1980s, the products of which are a mixture of cis- and trans-stilbenes. This reaction serves as an ideal example of how benchtop NMR spectrometers and analysis can support chemistry teaching laboratories.

Determination of reference intervals for equine arterial blood-gas, acid-base and electrolyte analysis

ObjectiveTo establish reference intervals for arterial blood-gas (ABG), acid-base and electrolyte values from a healthy equine population. Study designRetrospective clinical study. AnimalsA total of 139 client-owned, systemically healthy horses, 1 year of age and older, presented for elective surgical procedures. MethodsBlood samples were collected anaerobically from the transverse facial or common carotid artery of horses breathing room air, prior to administration of preanaesthetic medication. Samples were analysed immediately, without correction for body temperature, using an automated bench-top analyser. Variables analysed included pH, arterial partial pressure of carbon dioxide (PaCO2) and arterial partial pressure of oxygen (PaO2) and plasma concentrations of sodium (Na+), potassium (K+), calcium (Ca2+) and chloride (Cl−). Actual and standardized plasma bicarbonate concentration [HCO3− (P) and HCO3− (P, st)], blood and extracellular fluid base excess [base (B) and base (ECF)] and anion gap (AG) were calculated by the machine from preprogrammed algorithms. Methods used for determination of PaCO2, PaO2, HCO3− (P), HCO3− (P, st), base (B) and base (ECF) met the guidelines of the Clinical and Laboratory Standards Institute. Reference intervals were determined with the nonparametric or the standard parametric method dependent on data distribution. ResultsReference intervals were determined for pH, 7.37–7.49; PaCO2, 4.84–7.20 kPa (36.3–54.0 mmHg); PaO2, 11.01–14.97 kPa (82.6–112.3 mmHg); Na+, 133–141 mmol L–1; K+, 3.05–4.65 mmol L–1; Ca2+, 1.34–1.72 mmol L–1; Cl−, 100–110 mmol L–1; HCO3− (P), 23.55–33.90 mmol L–1; HCO3− (P, st), 23.87–32.45 mmol L–1; base (B), 0.51–8.80 mmol L–1; base (ECF), –0.53 to 9.39 mmol L–1 and AG, 1.5–11.5 mEq L–1. Conclusions and clinical relevanceThese data were derived from the largest group of horses reported in a single study and may aid in interpretation of ABG, acid-base and electrolyte measurements in clinical practice.

A Portable Setup for the Voltammetric Determination of Total Mercury in Fish with Solid and Nanostructured Gold Electrodes.

A simple procedure for field fish sample pretreatment was developed. This treatment in combination with square wave anodic stripping voltammetry (SW-ASV) with solid gold electrodes (SGE) and gold nanoparticle-modified glassy carbon electrodes (AuNPs-GCE) was applied for the determination of total mercury content. A certified reference material (CRM, Tuna Fish BCR 463), ten freeze-dried samples of canned tuna and two fresh fish samples were analysed both with a bench-top voltammetric analyser after microwave digestion and with a portable potentiostat after mild eating using a small commercial food warmer. The results obtained by the two SW-ASV approaches and by a Direct Mercury Analyser (DMA), the official method for mercury determination, were in very good agreement. In particular, (i) the results obtained with in field procedure are consistent with those obtained with the conventional microwave digestion; (ii) the presence of gold nanoparticles on the active electrode surface permits an improvement of the analytical performance in comparison to the SGE: the Limit of Quantification (LOQ) for mercury in fish-matrix was 0.1 μg L−1 (Hg cell concentration), corresponding to 0.06 mg kg−1 wet fish, which is a performance comparable to that of DMA. The pretreatment proposed in this study is very easy and applicable to fresh fish; in combination with a portable potentiostat, it proved to be an interesting procedure for on-site mercury determination.

System performance evaluation of STA satellite max, new bench top analyzer for the routine hemostasis lab

System performance evaluation of STA satellite max, new bench top analyzer for the routine hemostasis lab

Wearable Environmental Monitor To Quantify Personal Ambient Volatile Organic Compound Exposures.

Air pollution can cause acute and chronic health problems. It has many components, and one component of interest is volatile organic compounds (VOCs). While the outdoor environment may have regulations regarding exposure limits, the indoor environment is often unregulated and VOCs often appear in greater concentrations in the indoor environment. Therefore, it is equally critical to monitor both the indoor and outdoor environments for ambient chemical levels that an individual person is exposed to. While a number of different chemical detectors exist, most lack the ability to provide portable monitoring. We have developed a portable and wearable sampler that collects environmental VOCs in a person's immediate "exposure envelope" onto custom micro-preconcentrator chips for later benchtop analysis. The system also records ambient temperature and humidity and the GPS location during sampling, and the chip cartridges can be used in sequence over time to complete a profile of individual chemical exposure over the course of hours/days/weeks/months. The system can be programmed to accumulate sample for various times with varying periodicity. We first tested our sampler in the laboratory by completing calibration curves and testing saturation times for various common chemicals. The sampler was also tested in the field by collecting both indoor and outdoor personal exposure samples. Additionally under IRB approval, a teenaged volunteer wore the sampler for 5 days during which it sampled periodically throughout a 12 h period each day and the volunteer replaced the micro-preconcentrator chip each day.

Analytical Eco-Scale for Assessing the Greenness of a Developed Potentiometric Method for Lomefloxacin Hydrochloride Determination in its Different Dosage Forms, Plasma, and Dissolution Medium.

Background: Traditional methods for Lomefloxacin hydrochloride (LOM) determination involve pretreatment steps, which extend analysis time and use hazardous chemicals. Objective: The ability to provide a rapid route without sample pretreatment for quantitative determination of compounds via a low-cost instrument is a challenging task. In this work, a simple potentiometric method was developed to determine the antibacterial LOM via in-house fabricated ion selective electrodes. Methods: Different sensors were fabricated using a poly vinyl chloride-based membrane, potassium tetrakis(4-chlorophenyl) borate as a cation exchanger, and 2-Nitrophenyl octyl ether as a plasticizer (sensor 1). To increase the selectivity of sensor 1, a selective molecular recognition component 2-hydroxypropyl-β-cyclodextrin was used as ionophore (sensor 2). Results: The proposed method was validated according to International Union of Pure and Applied Chemistry recommendations, in which the proposed sensors show a linear dynamic range from 1 × 10-5 to 1 × 10-2 mol/L, with Nernstian slopes of 55.829 and 58.229 mV/decade for sensors 1 and 2, respectively. It was applied to determine LOM in bulk powder, in different dosage forms, and in plasma with no sample pretreatment. Also, the suggested method can be used as a green, in-line bench top real-time analyzer for in-process monitoring of LOM release from its tablets, under U.S. Food and Drug Administration dissolution regulations, with clear discrimination from common excipients. Results obtained by the proposed potentiometric method were compared with those obtained by a reported HPLC method. Conclusions: The proposed method is considered as a perfect alternative to traditional reported methods for LOM determination.

The impact of the introduction of a point-of-care haematology analyser in a New Zealand rural hospital with no onsite laboratory.

Hokianga Hospital is a small rural hospital in the far north of New Zealand serving a predominantly Maori population of 6500. The hospital, an integral part of a comprehensive primary healthcare service, provides continuous acute in-hospital and emergency care. Point-of-care (POC) biochemistry has been available at the hospital since 2010 but there is no onsite laboratory. This study looked at the impact of introducing a POC haematology benchtop analyser at Hokianga Hospital. This was a mixed methods study conducted at Hokianga Hospital over 4 months in 2016. Quantitative and qualitative components and a cost-benefit analysis were combined using an integrative process. Part I: Doctors working at Hokianga Hospital completed a form before and after POC haematology testing, recording test indication, differential diagnosis, planned patient disposition and impact on patient treatment. Part II: Focus group interviews were conducted with Hokianga Hospital doctors, nurses and a cultural advisor. Part III: An analysis of cost versus tangible benefits was conducted. Part I: A total of 97 POC haematology tests were included in the study. Of these, 97% were undertaken in the setting of the acute clinical presentation and 72% were performed out of hours. The average number of differential diagnoses reduced from 2.43 pre-test to 1.7 post-test, (χ2 tests p<0.05). There was a significant reduction in the number of patients transferred and an increase in the number of patients discharged home (χ2 tests p<0.05). Part II: Three main themes were identified: impact on patient management, challenges and the commitment to 'make it work'. POC haematology had a positive impact on patient management and clinician confidence mainly by increasing diagnostic certainty. The main challenges related to the hidden costs of implementing the analyser and its associated quality assurance program in a remote-from-laboratory setting. Part III: Tangible cost-benefit analysis showed a clear cost saving to the health system as a whole. This is the first published study evaluating the impact of haematology POC testing on acute clinical care in a rural hospital with no onsite laboratory. Timely access to a full blood count POC improves clinical care and addresses inequity. There was an overall reduction in healthcare costs. The study highlighted the hidden costs of implementing POC systems and their associated quality assurance programs in a remote-from-laboratory context.

Force and aspiration on catheters utilized in the ADAPT technique in acute ischemic stroke: A bench top analysis

IntroductionGiven the high morbidity and mortality of stroke, there remains a demand for techniques that provide rapid and safe intervention while improving time to recanalization. The direct aspiration first pass technique (ADAPT) uses force and aspiration for clot removal without the aid of separators or retrievers. In this study, we compare the force and aspiration qualities of commercially available catheters. MethodsFour different catheters with varying inner diameters were set up in a bench top model to test catheter tip pressure and flow rate. Catheter tip pressure was measured by attaching the catheter to a vacuum pressure gauge and an aspiration pump. The flow rate was calculated by measuring the volume of room temperature water aspirated through each catheter over a given time. ResultsThe Microvention Sofia catheter generated the greatest tip force (21.32 g), and the Stryker AXS Catalyst 6 catheter generated the smallest tip force (15.88 g). The Penumbra ACE 068 catheter and Medtronic ARC catheter measured 20.87 g and 16.78 g respectively. The ACE 068 had highest rate of aspiration at 289 mL/min, and the Catalyst 6 catheter had the lowest rate at 214. The Microvention Sofia catheter had the second highest rate while the ARC had the third highest rate, measuring 285 mL/min and 256 mL/min, respectively. ConclusionsWhen using the ADAPT technique, knowledge of the tip force and catheter flow rate of newer catheters with larger distal inner diameters may guide selection of aspiration catheters. While this study demonstrates differences in tip force and flow rate of different commercially available catheters, clinical translation will require further testing and evaluation.

EVALUATION OF SERIAL BLOOD LACTATE AND THE USE OF A POINT-OF-CARE LACTATE METER IN LIVE-STRANDED PINNIPEDS.

Live-stranded pinnipeds often present to rehabilitation centers systemically debilitated with dehydration and poor perfusion. In many terrestrial mammals, blood lactate elevation has been correlated with global tissue hypoxia and decreased circulating blood volume. Serial blood lactate measurements in companion animals and humans have been used to guide fluid resuscitation therapy and evaluate prognosis. The primary objective of this study was to evaluate the prognostic value of serial blood lactate levels in live-stranded pinnipeds in a rehabilitation setting. The secondary objectives were to evaluate the use of a point-of-care lactate meter, and potassium oxalate-sodium fluoride (gray-top) tubes for storing samples for lactate analysis in pinniped patients. Fifty-five live-stranded pinnipeds (30 northern elephant seals [Mirounga angustirostris], 21 Pacific harbor seals [Phoca vitulina richardsi], and four California sea lions [Zalophus californianus]) that presented to a rehabilitation center were manually restrained for blood collection and lactate measurement using a point-of-care analyzer (Lactate Plus™) prior to fluid or other medical therapy. Lactate measurements were repeated 72 hr post admission and prior to euthanasia or release. Plasma samples from gray-top tubes were frozen for 30-100 days at -80°C, then thawed and evaluated using both the LactatePlus and bench-top (ABL 815) analyzers. The point-of-care analyzer was successful in measuring lactate in pinnipeds. Gray-top tubes were effective at preserving lactate levels in frozen plasma samples for up to 100 days. Released animals had significantly greater lactate clearance at 72 hr (P = 0.039) than animals that died or were euthanized. Therefore, lactate clearance, determined by serial blood lactate measurements, may be useful for evaluating prognosis in live-stranded pinnipeds. Initial lactate and lactate values prior to euthanasia or release were not significantly associated with outcome. Given these findings, clinicians should interpret isolated lactate values in pinnipeds with caution.

Infrared backscatter imaging spectroscopy of trace analytes at standoff

We are developing a proximal noncontact detection technique for trace amounts of hazardous materials using diffuse reflectance infrared spectral signatures. Spectroscopy is performed at a distance by tuning a quantum cascade laser system through its wavelength range (6-11 μm) as the active illumination source and collecting a portion of the diffusely reflected light from the target onto an MCT focal plane array. The signals from each collected frame are binned and processed into an image hypercube that contains spectral and spatial information. The primary motivation of this work is to protect the loss of life by detecting trace explosives on contaminated surfaces before attacks occur. Here, we present results from backscatter experiments on trace samples with low loading and fill factors on glass substrates and compare them with a conventional benchtop analysis technique, FTIR diffuse reflectance. The backscatter results illustrate the ability to detect explosives at 1 m distance at the nanogram level, which is beyond the capability of the benchtop FTIR diffuse reflectance measurement.

Suitability of anodic stripping voltammetry for routine analysis of venous blood from raptors.

Lead (Pb) poisoning is a significant threat faced by raptors. Hence, rapid Pb diagnosis has become a priority during the admission of raptors in wildlife recovery centers, and bench-top analyzers, such as LeadCare II ®, are routinely employed for this purpose. However, this device has been designed for conducting analyses of human blood Pb levels (BLLs), and the validity of this methodology for whole blood from raptors has, to date, rarely been assessed. In addition, a recent recall by the US Food and Drug Administration has recommended discontinuing the use of this analyzer for human venous blood because it may underestimate the BLL. We evaluated the precision of BLL measurements taken with LeadCare II by comparing them with those obtained with inductively coupled plasma mass spectrometry (ICP-MS). Our sample contained venous blood from 105 raptors belonging to 4 species. The results showed a good correlation between the 2 techniques (Spearman's r = 0.927, p < 0.0001). The mean BLL with ICP-MS was 19.6 μg/dL; it was found to be 18.7 μg/dL with LeadCare II. A Bland-Altman analysis indicated that the bias between the mean differences was only 0.5 μg/dL, but it had a high standard deviation of bias (5.7 μg/dL) and 95% limits of agreement from -10.75 to 11.74 μg/dL. The present results indicated that LeadCare II has an overall sensitivity of 71.8% and a positive predictive value of 76.3%. The specificity of LeadCare II for detecting animals with low BLL (<3.4 μg/dL) was 96.4%, and the negative predictive value (the probability that a value below the limit of detection of LeadCare II has a true correspondence with the actual value) was 100%. The present results indicated that, although LeadCare II might be imperfect in the estimation of BLLs in raptors, it performs reasonably well and might be employed in the clinical setting to assess patients potentially suffering from Pb poisoning. Environ Toxicol Chem 2019;38:737-747. © 2018 SETAC.

Evaluation of the i‐STAT analyzer for determination of ionized calcium concentrations in bovine blood

Information regarding the performance of the i-STAT, a point-of-care analyzer, to determine ionized calcium (iCa2+ ) concentration in bovine blood is limited. The primary goal of this study was to evaluate the agreement of the i-STAT against a traditional bench-top blood gas analyzer (Radiometer ABL800 FLEX) in the measurement of iCa2+ in the blood of cattle with various disorders. In this study, 121 cattle with various diseases were used. Venous blood samples were run on the i-STAT and the Radiometer ABL800 FLEX for determination of blood iCa2+ concentrations. Data were subjected to Passing-Bablok regression and Bland-Altman plots. The Radiometer ABL800 FLEX was the reference method and the i-STAT was the test method. The i-STAT performance was evaluated at two different cutoff values for iCa2+ concentrations (<1.00 and <1.18mmol/L) using the receiver operating characteristic curve. The Passing-Bablok regression equation that fit the iCa2+ concentration as measured with the i-STAT (Y) and the Radiometer ABL800 FLEX (X), was Y=-0.108276 [-0.15/-0.06]+1.103448 [1.06/1.14]×X, with a residual deviation of 0.02. The deviation from the identity line was not significant (P=0.64). The Bland-Altman difference plot revealed no bias between the i-STAT and the Radiometer ABL 800 FLEX. The i-STAT had a sensitivity of 100% (95% CI, 87.7-100.0) and 94.8% (95% CI, 87.2-98.6) at the iCa2+ concentration cutoff values of <1.00 and <1.18mmol/L, respectively. iCa2+ concentrations in bovine blood measured with the i-STAT agreed with those of the Radiometer ABL800 FLEX. In particular, the i-STAT predicted hypocalcemia with a high sensitivity.