Spectrometric Detection System Research Articles

Steroid Hormones Effected in Human Body

Disturbances of the steroidogenesis or altered peripheral metabolism of steroids may result in severe clinical manifestations. Therefore, prompt diagnosis and initiation of medical treatment are desirable. The diagnostics of disorders of steroid hormone production, metabolism, and action have been previously based on immunoassay tests. However, in a modern medical laboratory, due to low accuracy of immunoassays, this technique is continuously replaced by chromatographic separation methods coupled to mass spectrometric detection systems. In this review we present current advances in the diagnostics of adrenal gland disorders, focusing on the role of mass spectrometry in prenatal and newborn screening, and in the diagnostics of sexual maturation disorders.

Correlation of Intraoperative 5-ALA-Induced Fluorescence Intensity and Preoperative 11C-Methionine PET Uptake in Glioma Surgery.

Simple SummaryIn malignant brain tumor surgery, precise identification of the tumor is essential. 5-Aminolevulinic acid (5-ALA) labels tumor cells with red fluorescence to facilitate tumor resection. On the other hand, the nuclear medicine imaging technique, positron emission tomography with 11C-methionine (MET-PET), can delineate tumors precisely but is not widely available. This study aimed to determine the correlation between intraoperative 5-ALA-induced fluorescence and preoperative MET-PET signals of gliomas. We quantitatively measured the fluorescence intensity from tumor samples and calculated the MET-PET uptake by the tumor. Our study showed that strong tumor fluorescence correlated with high MET-PET uptake and cellular proliferation. Our findings might be valuable to rapidly provide information on tumor biology at the time of surgery in circumstances where MET-PET is inaccessible.Background: 5-Aminolevulinic acid (5-ALA) is widely employed to assist fluorescence-guided surgery for malignant brain tumors. Positron emission tomography with 11C-methionine (MET-PET) represents the activity of brain tumors with precise boundaries but is not readily available. We hypothesized that quantitative 5-ALA-induced fluorescence intensity might correlate with MET-PET uptake in gliomas. Methods: Adult patients with supratentorial astrocytic gliomas who underwent preoperative MET-PET and surgical tumor resection using 5-ALA were enrolled in this prospective study. The regional tumor uptake of MET-PET was expressed as the ratio of standardized uptake volume max to that of the normal contralateral frontal lobe. A spectrometric fluorescence detection system measured tumor specimens’ ex vivo fluorescence intensity at 635 nm. Ki-67 index and IDH mutation status were assessed by histopathological analysis. Use of an antiepileptic drug (AED) and contrast enhancement pattern on MRI were also investigated. Results: Thirty-two patients, mostly with Glioblastoma IDH wild type (46.9%) and anaplastic astrocytoma IDH mutant (21.9%), were analyzed. When the fluorescence intensity was ranked into four groups, the strongest fluorescence group exhibited the highest mean MET-PET uptake and Ki-67 index values. When rearranged into fluorescence Visible or Non-visible groups, the Visible group had significantly higher MET-PET uptake and Ki-67 index compared to the Non-visible group. Contrast enhancement on MRI and IDH wild type tumors were more frequent among the Visible group. AED use did not correlate with 5-ALA-induced fluorescence intensity. Conclusions: In astrocytic glioma surgery, visible 5-ALA-induced fluorescence correlated with high MET-PET uptake, along with a high Ki-67 index.

Bile acid profiles in bile and feces of obese mice by a high-performance liquid chromatography-tandem mass spectrometry.

Bile acids (BAs) play a pivotal role in manipulating the development of metabolic diseases. However, due to the compositional complexity and functional variation of BAs, it remains unclear about the changes in BA pool for individuals with obesity or metabolic syndrome. We established a high-performance liquid chromatography-mass spectrometer detection system for the simultaneous analysis of both unconjugated and conjugated BAs in the bile and feces of mice. Ten BAs were completely separated, identified, and quantified with low limit of detection (0.5ng/mL) and inter/intraday precision (relative standard deviation<12%). By using this method, these BAs in bile and feces of mice were quantified. The result showed that taurochenodeoxycholic acid, taurine-conjugated α-muricholic acids, and taurine-conjugated β-muricholic acids were the dominated BAs in bile, whereas deoxycholic acid and chenodeoxycholic acid predominated in feces. Further, most of the BA levels were significantly elevated in either bile or fecal samples of high-fat diet-fed mice as compared with those in normal chow diet-fed mice, indicating that excessive production of BAs was closely associated with the occurrence of lipid metabolism disorders. In summary, the present method is practicable for analysis of BAs in bile and fecal samples of patients with obesity.

A portable detection method for organophosphorus and carbamates pesticide residues based on multilayer paper chip

AbstractOrganophosphorus and carbamates pesticide residues detection is one of significance in vegetables and fruits production. However, an effective directly detection method without any auxiliary has not been reported yet. Herein, we proposed a multilayer paper chip, including injection layer, heating layer, conduction layer, fixed enzyme layer, fixed indophenol acetate layer, and color layer, for pesticide residue of organophosphorus and carbamates detection based on the principles of enzyme inhibition reaction and heat generation inside. It's the first time for paper‐based chip to include an inside built‐in heating layer, which can ensure the reaction process with enzyme is always at the optimum temperature. Without any external instrument, we can determine whether the pesticide exceeds the standard according to the reaction color. Besides, we can also make quantitative detection of pesticide with external spectrometer detection system. The overall detection process runs automatically, then relatively accurate test results can be acquired. Under the optimum condition, a good linear correlation for dipterex concentrations over the range from 0.05 to 0.5 mg/L was obtained by quantitative detection, which can reach a detection limit (LOD) of 0.0406 mg/L. Besides, it also showed satisfactory reproducibility, specificity, and stability. Therefore, it is suitable for the instant detection technique.Practical applicationsThis article provides a method which is used to detect organophosphorus and carbamates pesticide residues existing in vegetables and fruits production. The detection limit is 0.0406 mg/L and it is lower than national standards. The detection reproducibility is acceptable. This method is energy‐saving and environment friendly. In this article, multilayer paper chip that includes enzyme inhibition reaction, color reaction and exothermic reaction was proposed. The heating layer in multilayer paper chip relies on the principle of chemical heat production and needs only a little water, which is very simple and easy. Under the whole process of detection without manual intervention, the testing result from the paper chip not only can be distinguished by eyes, but also can be detected precisely by simple detection device, which provide a basis for development of portable pesticide detector.

In-flight performance of the soft x-ray spectrometer detector system on Astro-H

The soft x-ray spectrometer (SXS) instrument was launched aboard the Astro-H (Hitomi) observatory on February 17, 2016. The SXS is based on a high-sensitivity x-ray calorimeter detector system that has been successfully deployed in many ground and suborbital spectrometers. The instrument was to provide essential diagnostics for nearly every class of x-ray emitting objects from the atmosphere of Jupiter to the outskirts of galaxy clusters, without degradation for spatially extended objects. The SXS detector system consisted of a 36-pixel cryogenic microcalorimeter array operated at a heat sink temperature of 50 mK. In preflight testing, the detector system demonstrated a resolving power of better than 1300 at 6 keV with a simultaneous bandpass from below 0.3 keV to above 12 keV with a timing precision better than 100 μs. In addition, a solid-state anticoincidence detector was placed directly behind the detector array for background suppression. The detector error budget included the measured interference from the SXS cooling system and the spacecraft. Additional margin for on-orbit gain stability and on-orbit spacecraft interference were also included predicting an on-orbit performance that meets or exceeds the 7-eV FWHM at 6-keV requirement. The actual on-orbit spectral resolution was better than 5 eV FWHM at 6 keV, easily satisfying the instrument requirement. Here, we discuss the actual on-orbit performance of the SXS detector system and compare this to performance in preflight testing and the on-orbit predictions. We will also discuss the on-orbit gain stability, additional on-orbit interference, and measurements of the on-orbit background.

CALCULATIONS OF SHUTDOWN DOSE RATE FOR THE TPR SPECTROMETER OF THE HIGH-RESOLUTION NEUTRON SPECTROMETER FOR ITER.

This work presents results of the calculations performed in order to predict the neutron-induced activity in structural materials that are considered to be using at the TPR spectrometer-one of the detection system of the High-Resolution Neutron Spectrometer for ITER. An attempt has been made to estimate the shutdown dose rates in a Cuboid #1 and to check if they satisfy ICRP regulatory requirements for occupational exposure to radiation and ITER nuclear safety regulations for areas with personal access. The results were obtained by the MCNP and FISPACT-II calculations.

Portable Agrichemical Detection System for Enhancing the Safety of Agricultural Products Using Aggregation of Gold Nanoparticles.

Organophosphorus (OP) and triazole chemicals have been commonly used as insecticides and fungicides to protect agricultural foods from harmful insects and fungi. However, these agrichemicals sometimes remain after distribution and can cause serious health and environmental issues. Therefore, it is essential to detect OPs and triazole chemicals in agricultural products. Nowadays, many detection techniques for OPs and triazole chemicals are expensive and time-consuming and require highly trained technicians. Thus, particularly rapid, simple, and sensitive detection methods are in demand for on-site screening of agrichemicals. Gold nanoparticles (AuNPs) have been utilized for applications in analytical assays and real-time monitoring in the biosensor field because of their biocompatibility and outstanding size-dependent optical properties. In this study, we used AuNPs as a detection probe, which have a size of 17 nm in diameter, a red color, and the absorbance peak at 520 nm. When imidazole was added to AuNPs mixed with the agrichemicals, the AuNPs aggregated and their colors changed to purple, causing the appearance of a new peak at 660–670 nm, which could be measured within approximately 20 s. Moreover, we developed a novel device for multiple agrichemical detections using an AuNP-aggregation-based spectrometric detection system. This portable device is light, simple, fast, and highly sensitive as well as selective. With this system, agrichemical residues can be easily detected on the spot at a low cost and in a short reaction time.

Design and Optimization of a Dual-HPGe Gamma Spectrometer and Its Cosmic Veto System

In this paper, a dual high purity germanium (HPGe) gamma spectrometer detection system with an increased solid angle was developed. The detection system consists of a pair of Broad Energy Germanium (BE-5030p) detectors and an XIA LLC digital gamma finder/Pixie-4 data-acquisition system. A data file processor was developed containing five modules that parses Pixie-4 list-mode data output files and classifies detections into anticoincident/coincident events and their specific coincidence types (double/triple/quadruple) for further analysis. A novel cosmic veto system was installed in the detection system. It was designed to be easy to install around an existing system while still providing sufficient cosmic veto shielding comparable to other designs. This paper describes the coverage and efficiency of this cosmic veto and the data processing system. It has been demonstrated that the cosmic veto system can provide a mean background reduction of 66.1%, which results in a mean MDA improvement of 58.3%. The counting time to meet the required MDA for specific radionuclide can be reduced by a factor of 2-3 compared to those using a conventional HPGe system. This paper also provides an initial overview of coincidence timing distributions between an incoming event from a cosmic veto plate and HPGe detector.

The Diagnostics of Human Steroid Hormone Disorders.

Disturbances of the steroidogenesis or altered peripheral metabolism of steroids may result in severe clinical manifestations. Therefore, prompt diagnosis and initiation of medical treatment are desirable. The diagnostics of disorders of steroid hormone production, metabolism, and action have been previously based on immunoassay tests. However, in a modern medical laboratory, due to low accuracy of immunoassays, this technique is continuously replaced by chromatographic separation methods coupled to mass spectrometric detection systems. In this review we present current advances in the diagnostics of adrenal gland disorders, focusing on the role of mass spectrometry in prenatal and newborn screening, and in the diagnostics of sexual maturation disorders.

Single-particle strength in neutron-richCu69from theZn70(d,He3)Cu69proton pick-up reaction

We have performed the $^{70}\mathrm{Zn}(d,^{3}\mathrm{He})^{69}\mathrm{Cu}$ proton pick-up reaction in direct kinematics using a deuteron beam at 27 MeV. The outgoing $^{3}\mathrm{He}$ particles were detected at the focal-plane detection system of an Enge split-pole spectrometer. The excitation-energy spectrum was reconstructed up to 7 MeV and spectroscopic factors were obtained after analysis of the angular distributions in the finite-range distorted-wave Born approximation. The results show three new angular distributions for which the $\ensuremath{\pi}{f}_{7/2}$ strength was measured and a lower limit of the centroid is established. State-of-the-art shell-model calculations are performed and predict a $\ensuremath{\pi}{f}_{7/2}$ strength that lies too high in energy in comparison to our experimental results.

A Rapid and Sensitive Method for the Analysis of Pyrethroid Pesticides Using the Combination of Liquid–Liquid Extraction and Dispersive Liquid–Liquid Microextraction

For the first time, combination of liquid–liquid extraction and dispersive liquid–liquid microextraction (LLE‐DLLME) is reported in this study. The method is efficient and was applied to the analysis of pyrethroid pesticides (fenpropathrin, sumithrin, cyhalothrin, permethrin, and deltamethrin) in fruit juices and fresh grape using gas chromatographic techniques with flame ionization detection system and mass spectrometric detection system. Five milliliter n‐hexane was used for the traditional liquid–liquid extraction of target analytes from 50 mL aqueous samples. After manual shaking, the supernatant phase (n‐hexane) was transferred into a test tube to which 0.75 mL dimethylformamide (DMF) was added then and the tube was shaken manually. After centrifugation, 0.6 mL of DMF was removed and used in a following DLLME procedure in which the extraction solvent was 20 μL of 1,1,2‐trichloroethane. Extraction with the optimized conditions resulted in linear analytical signals within the range 0.5–1200 μg L−1 and the limits of detection and quantification were in the ranges of 0.1–15 and 0.4–50 μg L−1, respectively. The method also showed high enrichment factors (2570–6835) and relatively good extraction recoveries (26–68%). Finally, the method was successfully applied to determination of analytes in tap water, strawberry juice, apricot juice, and fresh grape.

Enhancement effects of flat-mirror reflection on plasma radiation

Laser-induced breakdown spectroscopy quality can be improved by using a nanosecond Nd:YAG laser pulse to excite soil samples. To investigate how flat-mirror reflection affects the radiation characteristics of laser-induced plasma, emission spectra of sample elements were recorded using a grating spectrometer and photoelectric detection system. Placing a planar mirror vertically on the sample surface (10 mm mirror to plasma-center axis distance) for flat-mirror reflection increased spectral line intensities of Mg, Al, Fe, and Ba by 93.06%, 159.63%, 93.43%, and 94.61%, respectively. Signal-to-noise ratio increased by 17.56%, 40.21%, 31.29%, and 30%. The radiation enhancement mechanism was clarified using measured plasma parameters.

Application of magnetic nanoparticles for the extraction of radium-226 from water samples

Bare (unmodified) and crown ether (CE)- modified Fe3O4 magnetic nanoparticles (MNPs) were investigated for the rapid extraction of 226 Ra from water samples. It involved synthesizing the MNPs, introducing them into the sample solutions, ultrasonicating and agitat- ing the suspension, magnetically separating the nanoparti- cles from solution, and measuring the 226 Ra content in the supernatant. Experimental parameters such as salt choice, salt concentration and pH were optimized to achieve maximum extraction of 226 Ra onto the MNPs. 226 Ra con- tent was determined using a Hidex 300SL liquid scintilla- tion counter with a/b separation capability, or a gamma spectrometric detection system. The bare Fe3O4 nanopar- ticles showed significant pH dependence for the extraction of 226 Ra from an aqueous solution over a pH range of 2-10. They gave an extraction of 95 ± 1 and 98 ± 1 % at pH 9 in 0.1 M NaCl and 0.1 M NaClO4, respectively, whereas an extraction of 8-24 % was obtained, over the pH ranges from 2 to 5. The CE-modified MNPs yielded extraction efficiencies as high as 99 ± 1 % in the presence of 0.01 M picric acid at pH 4. This study demonstrates that the sur- face functionalization of Fe3O4 MNPs with suitable ligand modification can offer a selective mode of extraction for 226 Ra in the presence of its daughter progenies.

Sensitivity calibration of an imaging extreme ultraviolet spectrometer-detector system for determining the efficiency of broadband extreme ultraviolet sources

We report on the absolute sensitivity calibration of an extreme ultraviolet (XUV) spectrometer system that is frequently employed to study emission from short-pulse laser experiments. The XUV spectrometer, consisting of a toroidal mirror and a transmission grating, was characterized at a synchrotron source in respect of the ratio of the detected to the incident photon flux at photon energies ranging from 15.5 eV to 99 eV. The absolute calibration allows the determination of the XUV photon number emitted by laser-based XUV sources, e.g., high-harmonic generation from plasma surfaces or in gaseous media. We have demonstrated high-harmonic generation in gases and plasma surfaces providing 2.3 μW and μJ per harmonic using the respective generation mechanisms.

The Design of Spectrometer Detection and Control System Based on C8051F350

This paper designed a photoelectric detection system based on C8051F350 , which can be used in the grating spectrometer system. Aiming at traditional detecing methods, this paper puts forward a multi sensor data fusion technology which can fuse detecting data from multi photomultipliers. It has very strong practicability that detection data can be transmit to the computer through the serial port to draw curve of spectrum.

New determination of the mass of theηmeson at COSY-ANKE

A value for the mass of the eta meson has been determined at the COSY-ANKE facility through the measurement of a set of deuteron laboratory beam momenta and associated 3He center-of-mass momenta in the d+p -> 3He+X reaction. The eta was then identified by the missing-mass peak and the production threshold determined. The individual beam momenta were fixed with a relative precision of 3 x 10^-5 for values around 3 GeV/c by using a polarized deuteron beam and inducing an artificial depolarizing spin resonance, which occurs at a well-defined frequency. The final-state momenta in the two-body d+p -> 3He+eta reaction were investigated in detail by studying the size of the 3He momentum ellipse with the forward detection system of the ANKE spectrometer. Final alignment of the spectrometer for this high precision experiment was achieved through a comprehensive study of the 3He final-state momenta as a function of the center-of-mass angles, taking advantage of the full geometrical acceptance. The value obtained for the mass, m(eta)=(547.873 +- 0.005(stat) +- 0.027(syst)) MeV/c^2, is consistent and competitive with other recent measurements, in which the meson was detected through its decay products.

Pharmacokinetic profiles of hydrochlorothiazide alone and in combination with benazepril or valsartan in healthy Chinese volunteers: evaluation of the potential interaction

To compare the pharmacokinetic (PK) profiles and evaluate the PK interaction of hydrochlorothiazide (HCTZ) used alone and in combination with benazepril (BENA) or valsartan (VAL) in healthy Chinese volunteers. Data from two Phase I clinical trials (Study A and Study B) were combined and analyzed. Study A was an open, randomized, three-period crossover study. Eligible healthy male Chinese volunteers were randomly assigned to receive a single dose of the HCTZ (25 mg), BENA (20 mg) or HCTZ/BENA (25/20 mg). Study B was an open randomized, two-period crossover study of VAL/HCTZ (160/12.5 mg) in two formulations. A 7-day washout period was designed between alternate formulations in both studies. Multiple blood samples were collected up to 48 h post-dose, and plasma concentrations of HCTZ were analyzed using high performance liquid chromatography with tandem mass spectrometric detection (HPLC-MS/MS) system. Adverse events (AEs) were monitored and documented throughout the study period. 12 subjects completed Study A and 18 subjects completed Study B. Mean maximum plasma concentration (C(max)) was 168, 121 and 418 ng/ml and mean exposure (AUC(0-48 h)) was 1,160, 955 and 2,801 ng × h/ml following a single dose of HCTZ (25 mg) alone, BENA/HCTZ (20/25 mg) and VAL/HCTZ (160/12.5 mg), respectively. There was significant decrease in C(max) (90% confidence interval: 64.4 - 78.0%) and AUC(0-48 h) (90% confidence interval: 75.9 - 89.5%) of HCTZ with BENA co-administration, whereas concomitant VAL with HCTZ led to significant increase (approximate 1.5-fold) in C(max) and AUC(0-48 h) of plasma HCTZ even without dose normalizing. The apparent terminal half-life (t(1/2)) and the time to C(max) (tmax) were unchanged between the two studies. Overall, HCTZ alone as well as in combination with BENA and VAL was well tolerated within the scope of the current studies in Chinese health volunteers. BENA decreased the bioavailability of HCTZ in Chinese healthy volunteers while VAL greatly increased the concentration of HCTZ in plasma during coadministration. The combination of HCTZ with BENA or VAL was safe and well tolerated.

A fission product detection system of the magnetic spectrometer

An electronic fission-product detection system with the remote control from an IBM PC computer in the WINDOWS-XP environment has been designed to detect fission products in the focal plane of the mass spectrometer placed in the horizontal channel of the VVR-SM research reactor at the Institute of Nuclear Physics, Academy of Sciences of Uzbekistan and used for studying fission of heavy nuclei induced by reactor neutrons. A 32-strip semiconductor detector is for the first time used for these purposes. The detection system is composed of modules mounted in a single housing. C8051F127 programmable microcontrollers with built-in ADCs, DACs, RAMs, and other units, are the basis of each module, which allows data on the spatial distribution of fission products, their quantity, and energy to be collected and transmitted to a remote computer.

Elimination kinetics of diisocyanates after specific inhalative challenges in humans: mass spectrometry analysis, as a basis for biomonitoring strategies

BackgroundIsocyanates are some of the leading occupational causes of respiratory disorders, predominantly asthma. Adequate exposure monitoring may recognize risk factors and help to prevent the onset or aggravation of these aliments. Though, the biomonitoring appears to be most suitable for exposure assessment, the sampling time is critical, however. In order to settle the optimal time point for the sample collection in a practical biomonitoring approach, we aimed to measure the elimination of isocyanate urine metabolites.MethodsA simple biomonitoring method enabling detection of all major diamine metabolites, from mono-, poly- and diisocyanates in one analytical step, has been established. Urine samples from 121 patients undergoing inhalative challenge tests with diisocyanates for diagnostic reasons were separated by gas chromatography and analyzed with mass spectrometry (GC-MS) at various time points (0-24 h) after the onset of exposure.ResultsAfter controlled exposures to different concentrations of diisocyanates (496 ± 102 ppb-min or 1560 ± 420 ppb-min) the elimination kinetics (of respective isocyanate diamine metabolites) revealed differences between aliphatic and aromatic isocyanates (the latter exhibiting a slower elimination) and a dose-response relationship. No significant differences were observed, however, when the elimination time patterns for individual isocyanates were compared, in respect of either low or high exposure or in relation to the presence or absence of prior immunological sensitization.ConclusionsThe detection of isocyanate metabolites in hydrolyzed urine with the help of gas chromatography combined with mass spectrometric detection system appears to be the most suitable, reliable and sensitive method to monitor possible isocyanate uptake by an individual. Additionally, the information on elimination kinetic patterns must be factored into estimates of isocyanate uptake before it is possible for biomonitoring to provide realistic assessments of isocyanate exposure. The pathophysiological elimination of 1,6-hexamethylene diamine, 2,4-diamine toluene, 2,6-diamine toluene, 1,5-naphthalene diamine, 4,4'-diphenylmethane diamine and isophorone diamines (as respective metabolites of: 1,6-hexamethylene diisocyanate, 2,4-toluene diisocyanate and 2,6 toluene diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate and isophorone diisocyanates) differs between individual isocyanates' diamines.

Determination of drugs in “Alternative Biological Matrices”

With technological advances in extraction methods, immunoassay screening and instrumental techniques, interest in testing biological matrices other than urine, blood and serum has increased dramatically over the last few years. Almost every biological matrix can be tested in some way and provides unique information over other fluids and tissues. The increasing utility of immunoassay screening procedures, specifically ELISA, in forensic laboratories provides two major benefits: 1) biological background is washed away, enhancing the sensitivity of the assays and 2) automated instrumentation has allowed an increase in the number and type of specimens which can be processed on a routine basis. Finally, the availability and affordability of bench-top liquid chromatographic systems with tandem mass spectrometric detection systems (LC-MS/MS) has allowed confirmatory methods to be reliably implemented. doi:10.1016/j.scijus.2009.09.009 50 years of forensic toxicology