Spectrometric Properties Research Articles

Индекс качества Диксона: связь с технологическим воздействием на лесные семена

A comprehensive indicator of predicting the quality of planting material at the time of planting – the Dickson quality Index (DQI) – is currently widely represented in studies of the growth and development of forest crops, but is not limited to them. Based on the systematization of data to a depth of 10 years returned by the term [Scholar Query = "Dickson quality index"], on the dynamics of the Dickson quality index depending on the criteria of technological impact on seeds and seedlings (seedlings), a hierarchical classification was carried out using the method of the most distant neighbors to describe the similarity between the criteria. Data grouping was performed using the square of the Euclidean distance. The change in the DQI index in most cases can be approximated by a second-order polynomial. The technological impact on seeds before sowing on the basis of the convergence and difference method is significantly (p < 0.05) allocated to a separate cluster (the square of the Euclidean distance is 4), which suggests a possible contribution to the assessment of the quality of planting material using DQI. In future studies, it is planned to get an answer to the question: what effect does the separation of seeds by spectrometric properties have on the dynamics of the DQI index in the process of ontogenesis? How does the dimensionality of the ratio of plant height to the diameter of the root neck affect the accuracy of the DQI estimate?

A Novel Coenzyme A Analogue in the Anaerobic, Sulfate-Reducing, Marine Bacterium Desulfobacula toluolica Tol2T.

Coenzyme A (CoA) thioesters are formed during anabolic and catabolic reactions in every organism. Degradation pathways of growth-supporting substrates in bacteria can be predicted by differential proteogenomic studies. Direct detection of proposed metabolites such as CoA thioesters by high-performance liquid chromatography coupled with high-resolution mass spectrometry can confirm the reaction sequence and demonstrate the activity of these degradation pathways. In the metabolomes of the anaerobic sulfate-reducing bacterium Desulfobacula toluolica Tol2T grown with different substrates various CoA thioesters, derived from amino acid, fatty acid or alcohol metabolism, have been detected. Additionally, the cell extracts of this bacterium revealed a number of CoA analogues with molecular masses increased by 1 dalton. By comparing the chromatographic and mass spectrometric properties of synthetic reference standards with those of compounds detected in cell extracts of D. toluolica Tol2T and by performing co-injection experiments, these analogues were identified as inosino-CoAs. These CoA thioesters contain inosine instead of adenosine as the nucleoside. To the best of our knowledge, this finding represents the first detection of naturally occurring inosino-CoA analogues.

ВЛИЯНИЕ КЛИМАТИЧЕСКОГО ИНДЕКСА ГРАДУСО-ДНЕЙ НА ВИТАЛИТЕТ 3-ЛЕТНИХ СЕЯНЦЕВ СОСНЫ ОБЫКНОВЕННОЙ ИЗ СОРТИРОВАННЫХ ПО СПЕКТРОМЕТРИЧЕСКИМ СВОЙСТВАМ СЕМЯН

The natural and production conditions of the growth of scots pine during forest restoration determine the research of the degree of interrelation of exogenous temperature factors with and technological processes of seed sorting with the quality of forest reproductive material. Descriptive statistics of biometric parameters of the height and diameter of the root neck were determined for the first, second, and third growing periods of individuals of Scots pine obtained by autumn transplanting containerized (1+0) seedlings sprouted from seeds conditioned by spectrometric properties to a post-pyrogenic site. The correlation relationship of the average variant of the exogenous index of degree days GDD, as well as the average variant of vitality indices was evaluated using the Spearman method based on the SPSS Statistics application software package. The degree of influence of the exogenous degree-day index on the DQI index of Scots pine crops in the 3rd growing season after transplanting containerized seedlings (1+0) sprouted from seeds of different spectrometric fractions is characterized by a weak positive correlation (p = 0.170; p = 0.05). The technological process of separating the light fraction of Scots pine seeds for the production of containerized seedlings demonstrates the best vitality indices in transplanted crops at the end of VP-III, statistically significantly (p = 0.05) differing from other spectrometric groups within the natural production conditions of this study

Organic Matter in Riverbank Sediments and Fluvisols from the Flood Zones of Lower Vistula River

The research objective of this study was to determine whether and to what extent the form of use of Fluvisols (arable soil and grassland) of a Lower Vistula floodplain valley (Fordonska Valley, Poland) determined their relative organic matter properties, as compared with nearby riverbank sediments. Riverbank sediments were sampled from a depth of 0–20 cm, and soil samples from 0 to30 cm, all in three replicates. Basic physico-chemical soil properties were determined: texture, pH, and the contents of total organic carbon (TOC), total nitrogen (TN), dissolved organic carbon (DOC) and dissolved organic nitrogen (DON). Humic acids (HAs) were extracted by the Schnitzer method and analysed to assess their spectrometric parameters in the UV–VIS range and hydrophilic and hydrophobic properties. Riverbank sediment samples contained significantly lower TOC and TN contents than Fluvisols, regardless of land-use type. The TOC, TN, DOC and DON contents and properties of humic acids in the Fluvisol surface layer depended on land-use type, because the arable soils had significantly lower TOC, TN, DOC and DON contents than the grasslands, despite having a similar grain size (texture). Based on the A2/4, A2/6, A4/6 ratios, it was found that HA molecules isolated from the humus horizon of arable soils had a higher degree of maturity than HAs isolated from grassland soil samples. The spectrometric properties of humic acids isolated from riverbank sediments showed a higher degree of maturity than those from Fluvisols. This research showed that the properties of humic acids in Fluvisols are determined by the quantity and quality of organic matter transported in suspended matter that accumulates annually in flood valleys during flood events. The current land-use type of Fluvisols significantly influenced the properties of organic matter, and thus of humic acids. Therefore, these properties can be used to evaluate the transformation of organic matter that occurs in Fluvisols depending on the type of use.

A Novel Method for Spectrometry Based on Imaging Systems

γ-ray spectrometry is a well-known technique in environmental radioactivity measurements where easily handled systems are needed. Scintillators coupled to a photomultiplier tube (PMT), are typically favoured over solid-state detectors as mobile spectrometers. Replacing PMT with position sensitive devices represents an innovative solution that provides the evaluation of the interaction point of the incident radiation. The knowledge of spectrometry as a function of the depth of interaction (DoI) assures a better understanding of the spectrum and a more reliable identification of the source. In this paper, the efficiency of a simple DoI estimator has been studied using a CRY018 monolithic crystal coupled to a multi-anode photomultiplier tube. The DoI estimator has been evaluated studying charge distributions and the dependency of spectrometric properties on the DoI has been qualitatively analyzed. The estimator has shown to be highly sensitive to the DoI, enabling a better understanding of the internal interaction processes of light and an efficient rejection of the background component on the spectra. The novelty of this work lies in the application of the DoI selection in spectrometry made available by the use of MAPMT. The proposed method is practical since it does not require complicated hardware solutions or complex computational procedures.

Polarization effect of Schottky-barrier CdTe semiconductor detectors after electron irradiation

Spectrometric properties of cadmium telluride (CdTe) radiation semiconductor detectors with Schottky-barrier contacts were studied after irradiation with a high energy electron beam of 5 MeV-energy. The total cumulative dose of 2.25 kGy was delivered stepwise and the response of detectors to 241Am radioisotope source was acquired using a standard spectrometric chain at reverse bias voltages of 300 V, 400 V and 500 V. To evaluate the radiation damage, the spectral parameters of the 59.5 keV-photopeak were determined, namely the peak position, the full width at half maximum (FWHM), the peak amplitude and the net peak area. The time evolution of these parameters was followed by recording the spectra in 30-seconds (or 2-minutes) intervals after applying the reverse bias voltages. The results demonstrated significant effect of high energy electrons on the spectral characteristics even after applying the lowest dose of 0.5 kGy. The shift of the photopeak to lower energies, the increase of the FWHM and decrease of the peak height and area were confirmed. The time evolution of the observed tendencies disclosed that electron irradiation results in earlier onset of the polarization mechanism. After irradiating with the highest dose of 2.25 kGy, the polarization effect occurs practically immediately after applying the bias voltage.

Metabolomics of Chlorophylls and Carotenoids: Analytical Methods and Metabolome-Based Studies.

Chlorophylls and carotenoids are two families of antioxidants present in daily ingested foods, whose recognition as added-value ingredients runs in parallel with the increasing number of demonstrated functional properties. Both groups include a complex and vast number of compounds, and extraction and analysis methods evolved recently to a modern protocol. New methodologies are more potent, precise, and accurate, but their application requires a better understanding of the technical and biological context. Therefore, the present review compiles the basic knowledge and recent advances of the metabolomics of chlorophylls and carotenoids, including the interrelation with the primary metabolism. The study includes material preparation and extraction protocols, the instrumental techniques for the acquisition of spectroscopic and spectrometric properties, the workflows and software tools for data pre-processing and analysis, and the application of mass spectrometry to pigment metabolomics. In addition, the review encompasses a critical description of studies where metabolomics analyses of chlorophylls and carotenoids were developed as an approach to analyzing the effects of biotic and abiotic stressors on living organisms.

Impact of forest trees on the soil reflectance and their relation of soil oxides in Sherawa village, Erbil government- Iraq

Soil reflectance spectroscopy has become a pioneering technique for quantifying soil properties that provide data for soil classification and digital soil mapping studies. This work was conducted with the aim to analyze the spatial variability of soil spectrometric properties between surface and subsurface soil under three land use patterns namely; pine, barren land and oak in Sherawa village, northeast Iraq.
 Soil samples were collected from the three land types at two depths: surface soil at 0–15 cm and subsurface soil at 15–30 cm in duplicates totaling 6 collected soil samples. The elemental composition and mineral phases of soils were determined by X-ray fluorescent XRF and X-ray diffraction (XRD) respectively for qualitative and quantitative characterization. Magnesium oxide (MgO) was highest detected concentration in the surface soil layer reaching 34.16%, 36.75%, and 33.63%, respectively for pine, barren land and oak compared to 41.57%, 38.54%, 33.94% of the respective concentration in the subsurface soil layer samples of pine, barren and oak. Whereas, calcium and iron were the lowest percentages of pine in the surface and subsurface soil layer samples by (2.19%, 4.85%, 3.39%, and 4.55%, respectively). At the same time as, the percentages of oak in the surface and subsurface soil layer samples were (2.24%, 4%, 2.99% and 4.93%, respectively).The results indicate that the use of spectrometric analysis of soils in the field or in the laboratory can positively enhance soil characterization and typification surveys. Moreover, the influence of the silicates near 1400 nm by Al or Mg-OH and OH group were very apparent in the SWIR spectral regions of oak and pine in the subsurface soil. The results also showed the differences in soil color and reflectance between surface soil samples and subsurface surface soil for all site locations. Further studies are proceeding for more investigation at larger scale concerning analyzing the spatial variability of soil spectrometric properties with depth under different land use patterns..

Current-voltage characterization of GaAs detectors and their holders irradiated by high-energy electrons

In our radiation hardness studies we observed that SI GaAs detectors irradiated by 5 MeV electrons exhibited different behaviour with applied dose when considering their electrical and spectrometric properties. The detectors were prepared by the same technology using one GaAs wafer differing in the type of holder used to wire-bond the detectors. In this paper the commercially available detector holders together with self-prepared ones were irradiated by 5 MeV electrons under the same conditions as the investigated detectors before. Three types of detector holders were studied to evaluate their radiation hardness: holders prepared on a Printed Circuit Board (PCB), Poly-Vinyl-Chloride (PVC) holders and two different ceramic holders. The best radiation stability was obtained with a holder self-made from aluminium oxide ceramics using gold metallization. The PCB and the PVC holders exhibited similar radiation stability. The most unstable at doses over 500 kGy was the holder made by silk-screen printing technology from ceramics with silver metallization. No significant influence of the dose rate used during irradiation (in the range from 20 to 80 kGy/h) was observed in all types of holders.

Detection of Scots Pine Single Seed in Optoelectronic System of Mobile Grader: Mathematical Modeling

The development of mobile optoelectronic graders for separating viable seeds by spectrometric properties with high detection accuracy represents a very relevant direction of development for seed handling operations. Here, the main parameters of the radiation source and receiver for detecting a single seed in the diagnostic system of a mobile grader were modeled based on the principles of technical optics using Scots pine (Pinus sylvestris L.) seeds as a case study. Among the pine seeds in the seed batch, there are fossilized and empty seeds that are exactly the same in geometric and gravitational parameters as live seeds. For their separation from the seed batch, data from spectrometric studies in the near-infrared (980 nm) region can be used. To substantiate the parameters of the light source, a geometric optical model of optical beam formation was considered, while the energy model of optical beam formation was considered to substantiate the parameters of the light detector. The results of this study show that the signal value depended on the orientation of a single seed relative to the recording window. The beam angle from the radiation source should be within 45 degrees. The difference between the optical streams should be 50 microns, which made it possible to clearly detect the signal at a standard noise level of 15 microns and signal-to-noise detection accuracy ratio of 56.3 dB. This study expands theoretical knowledge in the field of the spectrometric properties of a single seed, considering the cases of its orientation relative to the optical beam, which affected the effective area of detection of the seed. The obtained data on the location of the main elements of the diagnostic system will speed up the design of mobile optoelectronic graders, and the development of a contemporary protocol for improving Scots pine seed quality.

Synthesis of (E)-1,2-Bis[4-[di(1H-pyrrol-2-yl)methyl]phenyl]ethene as a New Bis(dipyrromethane) Building Block

Dipyrromethanes are useful intermediates in the synthesis of porphyrins and their analogs. In this paper, we report the synthesis of a new bis(dipyrromethane) {(E)-1,2-bis[4-[di(1H-pyrrol-2- yl)methyl]phenyl]ethene}, from (E)-4,4'-1,2-ethenediylbis(benzaldehyde), showing a long resonance chain with improved UV spectrometric properties. This product has high potential in the synthesis of new bis(porphyrins) or other related compounds.

Effect of the Tillage System on the Properties of Humic Acids of Soil of the Kujawy Region in Poland

The aim of this study has been to determine the properties of humic acids of soil depending on the tillage system applied. The study covered the soil where plough tillage, strip-till and ploughless tillage were used, and so the systems which differed completely in the way they affect the post-harvest residue, “plant residue management”. From averaged samples of soil humic acids (HAs) were extracted to identify their elemental composition, spectrometric properties for the UV-VIS and IR range as well as hydrophilic-hydrophobic properties.
 
 With the results one can conclude that the humic acids of the soil under plough tillage show a lower degree of humification as compared with HAs of ploughless tillage, whereas the parameters recorded for HAs of the soil with strip-till point to the similarity to HAs of soil with plough tillage and ploughless tillage. With that in mind, with some approximation, the degree of humification (maturity) of HAs can be ordered as follows: HAs with plough tillage < HAs with strip-till < HAs with ploughless tillage. Thus one can conclude that the tillage method combines two primary objectives; ensuring conditions favourable to plant growth and development and the effort to maintain the possibly highest humus stability.

Glutathionyl-S-chlorogenic acid is present in fruit of Vaccinium species, potato tubers and apple juice.

A hydroxycinnamate-like component was identified in highbush blueberry (Vaccinium corymbosum) fruit, which had identical UV and mass spectrometric properties to an S-linked glutathionyl conjugate of chlorogenic acid synthesized using a peroxidase-catalyzed reaction. The conjugate was present in fruits from all highbush blueberry genotypes grown in one season, reaching 7-20% of the relative abundance of 5-caffeoylquininc acid. It was enriched, along with anthocyanins, by fractionation on solid phase cation-exchange units. Mining of pre-existing LC-MS data confirmed that this conjugate was ubiquitous in highbush blueberries, but also present in other Vaccinium species. Similar data mining identified this conjugate in potato tubers with enrichment in peel tissues. In addition, the conjugate was also present in commercial apple juice and was stable to pasteurization and storage. Although glutathionyl conjugates of hydroxycinnamic acids have been noted previously, this is the first report of glutathionyl conjugates of chlorogenic acids in commonly-eaten fruits and vegetables.

Solid solubility measurement of ipriflavone in supercritical carbon dioxide and microparticle production through the rapid expansion of supercritical solutions process

In this study, the solid solubilities of ipriflavone in supercritical CO2 were measured by using a semi-flow apparatus. The Chrastil equation, Mendez-Santiago and Teja equation, and a solution model developed from the regular solution model and Flory–Huggins equation were adopted to correlate the measured solubility data. Because the solubility in mole fraction of ipriflavone can be as high as 10−4, the rapid expansion of supercritical solutions (RESS) process was adopted to produce ipriflavone microparticles. The effects of the operating parameters of the RESS process on the mean particle size of ipriflavone were evaluated and discussed. In addition, based on the results of powder X-ray diffraction, differential scanning calorimetry, and Fourier-transform infrared spectrometry analysis, particulate ipriflavone exhibited consistency with the unprocessed sample in terms of crystal structure, melting temperature, and spectrometric properties.

Radiation hardness limits in gamma spectrometry of semi-insulating GaAs detectors irradiated by 5 MeV electrons

A radiation hardness study of developed Schottky barrier semi-insulating (SI) GaAs detectors against 5 MeV electrons is described in this paper. The influence of cumulative dose (up to 1000 kGy) and the applied dose rate (20, 40 or 80 kGy/h) on spectrometric and electrical properties of detectors is presented. The spectrometric properties were evaluated from measured 241Am gamma spectra and the electrical properties were obtained measuring the current-voltage characteristics. The cumulative dose has negatively affected all spectrometric properties. The detector CCE (Charge Collection Efficiency) exponentially decreased with dose from initial 74% down to 24% at maximum applied dose of 1000 kGy. The relative energy resolution was increasing from 17% before irradiation up to almost 50% at maximum dose applied. The peak-to-valley ratio firstly increased from 10 to 17 at 24 kGy and then rapidly decreased below 2 at 200 kGy. The electrical properties were obtained from measured current-voltage characteristics of detectors. The breakdown voltage of detectors firstly decreased to 60% of its original value and at few hundred kGy it started to increase exceeding the initial value twice. The reverse current exhibited similar behaviour decreasing up to 200 kGy and then increasing. Concerning obtained results we can determine the limit of sufficient functionality of developed SI GaAs detectors against 5 MeV electrons to be 1000 kGy for 59.5 keV particles. The second investigated parameter of irradiation, the dose rate in chosen ranges, did not greatly alter the spectrometric properties of studied detectors.

Effects of electron irradiation on spectrometric properties of Schottky barrier CdTe radiation detectors

High detection efficiency and good room temperature performance of Schottky barrier CdTe semiconductor detectors make them well suited especially for X-ray and gamma-ray detectors. In this contribution, we studied the effect of electron irradiation on the spectrometric performance of the Schottky barrier CdTe detectors manufactured from the chips of size [Formula: see text] mm3 with In/Ti anode and Pt cathode electrodes (Acrorad Co., Ltd.). Electron irradiation of the detectors was performed by 5 MeV electrons at RT using a linear accelerator UELR 5-1S. Different accumulated doses from 0.5 kGy up to 1.25 kGy were applied and the consequent degradation of the spectrometric properties was evaluated by measuring the pulse-height gamma-spectra of [Formula: see text] radioisotope source. The spectra were collected at different reverse voltages from 300 V up to 500 V. The changes of selected significant parameters, like energy resolution, peak position, detection efficiency and leakage current were monitored and evaluated to quantify the radiation hardness of the studied detectors. The results showed remarkable worsening of their spectrometric parameters even at relatively low applied doses of 1.25 kGy.

Experimental Study on Vacuum Performance of Parabolic Trough Receivers based on a Novel Non-destructive Testing Method

The loss of vacuum in the parabolic trough receivers is one of the most common problems in the parabolic trough solar power plants. The vacuum level and gas species in the annulus of the receiver determine the heat loss and have an important influence on the thermal efficient of the solar system. If hydrogen is inside the annulus, it can cause heat losses to be almost four times that of a receiver with good vacuum. However, it is hard to non-destructively measure the gas species and partial pressure in the annulus of the receiver. In this paper, a novel non-destructive method was presented to evaluate the vacuum performance by using combined dielectric barrier discharge and the spectral analysis technology. The discharge characteristics and spectrometric properties of four kinds of gases, which are the most likely gases to be found in the receivers, were studied in the experiments. The test results of the non-destructive vacuum evaluation method agree well with the results of the residual gas analysis. The feasibility and accuracy of the non-destructive test method was verified. The relationship between the vacuum performance of receiver and the spectral characteristics of dielectric barrier discharge were obtained by a series of experiments.

Fluorescent and mass spectrometric evaluation of the phagocytic internalization of a CD47-peptide modified drug-nanocarrier.

Ru(bpy)3@SiO2-COOH and Ru(bpy)3@SiO2@CD47-peptide nanoparticles (NPs) with fluorescent and mass spectrometric properties were designed and synthesized as the models of drug-nanocarriers. Their phagocytic internalization could be quantitatively measured using more sensitive inductively coupled plasma mass spectrometry (ICPMS) (102Ru) versus traditional laser confocal scanning microscope (λex/em = 458/600nm) for the first time. Modification of a self-signal trigging CD47-peptide on the NPs' surface decreased internalization by 10 times, (2.79 ± 0.21) × 104 Ru(bpy)3@SiO2-COOH and (0.28 ± 0.04) × 104 Ru(bpy)3@SiO2@CD47-peptide NPs per RAW264.7 macrophage (n = 5). The alkynyl-linked CD47-peptide allowed us to quantify the number (2412 ± 250) of CD47-peptide modified on the NP and the total content (5.14 ± 0.25 amol) of signal regulatory protein α (SIRPα) on the macrophage by measuring the clickable tagged Eu using ICPMS. Furthermore, the interaction between CD47-peptide and SIRPα as well as the changes of the remaining free SIRPα during the internalization process of Ru(bpy)3@SiO2@CD47-peptide NPs were quantitatively evaluated, providing direct experimental evidence of the longspeculated crucial CD47-SIRPα interaction for drug-nanocarriers to escape internalization by phagocytic cells. Remarkable difference in the internalization ratio of 12.3 ± 4.8 of Ru(bpy)3@SiO2-COOH NPs and 4.3 ± 0.5 Ru(bpy)3@SiO2@CD47-peptide NPs with and without the protein corona indicated that CD47-peptide still worked when the protein corona formed. Not limited to the evaluation of the NPs studied here, such a fluorescent and mass spectrometric approach is very much expected to apply to the assessment of other drug-nanocarriers designed by chemists and before their medical applications. Graphical abstract.

CYSP-BEAM: A multi-detector directional spectrometer for in-beam neutron spectrometry

CYSP-BEAM is a directional neutron spectrometer formed by a thick polyethylene cylindrical collimator followed by a sensitive capsule that contains several active thermal neutron detectors located at different depths along the cylindrical axis. Due to a thick lateral shield made of polyethylene and borated rubber, only neutrons from the direction identified by the collimating aperture can reach the internal detectors. As the response function of the internal detectors tend to peak at increasing energies as the detector depth increases, the device has spectrometric properties. This type of moderated spectrometer, whose prototype was the CYSP (CYlindrical SPectrometer), is capable to combine the functionalities of Bonner Spheres in a single device, thus requiring only one exposure to measure all the energy components of the incident beam, from thermal up to GeV neutrons. The neutron spectrum is obtained via few-channel unfolding methods. With respect to the original CYSP, the new CYSP-BEAM device is optimized to operate in the direct intense beam of neutron producing installations, such as large scale neutron science facilities. Compared with CYSP, CYSP-BEAM has narrower collimating aperture and the internal detectors have sensibility a factor 100 lower. Its response matrix was simulated using MCNPX. This paper describes the new device focusing on the internal detectors, the response matrix and the test measurement performed using the 14 MeV beam produced at the ENEA Frascati Neutron Generator (FNG).

Characterization of Bromethalin and its Degradation Products in Veterinary Toxicology Samples by GC-MS-MS.

Bromethalin is a neurotoxicant with unusual instability and chromatographic behavior that make it difficult to analyze by gas chromatography (GC) in forensic examination of non-target animal deaths. Physicochemical breakdown of bromethalin produced multiple unique products with discernible mass spectra. This paper describes an investigation of the GC electron impact-mass spectrometric properties of bromethalin and its capacity to generate up to twenty heat- or light-induced breakdown products. Two principal breakdown products are isomeric with one another and involve release of both fluorine and methyl groups to develop dehydrofluorodesmethylbromethalin products. These compounds have proven to be excellent surrogate markers in screening forensic samples for bromethalin exposure, particularly in veterinary samples in which the active metabolite desmethylbromethalin has not yet accumulated to any appreciable extent, such as baits and animal stomach contents. The compounds as well as their parent bromethalin were easily monitored by GC interfaced with a tandem-quadrupole mass spectrometer using multiple-reaction monitoring (MRM) modes. Unusual gas chromatographic properties of bromethalin included: (i) specific requirements for a maximum oven temperature; (ii) non-linear increases in detector response on increased injection volumes, hypothesized to result from variable diffusion coefficients. We report here the development of GC strategies that facilitate detection of bromethalin and its breakdown products, as well as their MRM analysis by tandem-quadrupole mass spectrometry. The developed approaches are applicable to feed, baits and stomach contents as well as extracted tissue samples such as liver and kidney.