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1.
Talanta ; 235: 122686, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517576

RESUMO

Counterfeiting is an omnipresent issue, among others in the cosmetics industry or on the art market. Particularly in the case of very expensive perfumes or very valuable art objects, counterfeits are strongly represented and are steadily increasing. Typically, the content of perfumes is analyzed, but the bottle offers another level of authentication, as it is an essential part of the product. For art objects made of glass, glass is an essential part of the artwork and thus provides an important contribution to the authenticity of the object. In the present pilot study, we developed a laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) method to classify glass using perfume bottles manufactured at different production facilities, Germany, India, Peru and Poland as an example. Using minimally invasive laser ablation invisible to the eye, we were able to detect counterfeit flacons without having to open the vials. A total of 63 elements could be recorded during method development. After statistical evaluation (t-test, ANOVA, principal component analysis (PCA)), 15 (Li, Na, Al, Ti, V, Co, Rb, Sr, Mo, Ba, La, Ce, Pr, Er and Pb) significant marker elements were extracted from the data sets to differentiate the different glass origins. By using LDA, six different production sites from four different countries could be differentiated over a sample period of six months with a prediction accuracy of 100%.


Assuntos
Terapia a Laser , Vidro , Espectrometria de Massas , Projetos Piloto , Análise Espectral
2.
Talanta ; 235: 122725, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517593

RESUMO

Analysis of the spatial distribution of metals, metalloids, and non-metals in biological tissues is of significant interest in the life sciences, helping to illuminate the function and roles these elements play within various biological pathways. Chemical imaging methods are commonly employed to address biological questions and reveal individual spatial distributions of analytes of interest. Elucidation of these spatial distributions can help determine key elemental and molecular information within the respective biological specimens. However, traditionally utilized imaging methods prove challenging for certain biological tissue analysis, especially with respect to applications that require high spatial resolution or depth profiling. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been shown to be effective for direct elemental analysis of solid materials with high levels of precision. In this work, chemical imaging using LA-ICP-MS has been applied as a powerful analytical methodology for the analysis of liver tissue samples. The proposed analytical methodology successfully produced both qualitative and quantitative information regarding specific elemental distributions within images of thin tissue sections with high levels of sensitivity and spatial resolution. The spatial resolution of the analytical methodology was innovatively enhanced, helping to broaden applicability of this technique to applications requiring significantly high spatial resolutions. This information can be used to further understand the role these elements play within biological systems and impacts dysregulation may have.


Assuntos
Terapia a Laser , Fígado , Espectrometria de Massas , Metais , Análise Espectral
3.
Talanta ; 235: 122741, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517609

RESUMO

Recently nanoparticle enhanced Laser Induced Breakdown Spectroscopy (NELIBS) is getting a growing interest as an effective alternative method for improving the analytical performance of LIBS. On the other hand, the plasmonic effect during laser ablation can be used for a different task rather than elemental analysis. In this paper, the dependence of NELIBS emission signal enhancement on nanoparticle-protein solutions dried on a reference substrate (metallic titanium) was investigated. Two proteins were studied: Human Serum Albumin (HSA) and Cytochrome C (CytC). Both proteins have a strong affinity for the gold nanoparticles (AuNPs) due to the bonding between the single free exterior thiol (associated with a cysteine residue) and the gold surface to form a stable protein corona. Then, since the protein sizes are vastly different, a different number of protein units is needed to cover AuNP surface to form a protein layer. The NP-protein solution was dropped and dried onto the titanium substrate. Then the NELIBS signal enhancement of Ti emission lines was correlated to the solution characteristics as determined with Dynamic Light Scattering (DLS), Surface Plasmon Resonance (SPR) spectroscopy and Laser Doppler Electrophoresis (LDE) for ζ-potential determination. Moreover, the dried solutions were studied with TEM (Transmission Electron Microscopy) for the inspection of the inter-particle distance. The structural effect of the NP-protein conjugates on the NELIBS signal reveals that NELIBS can be used to determine the number of protein units required to form the nanoparticle-protein corona with good accuracy. Although the investigated NP-protein systems are simple cases in biological applications, this work demonstrates, for the first time, a different use of NELIBS that is beyond elemental analysis and it opens the way for sensing the nanoparticle protein corona.


Assuntos
Nanopartículas Metálicas , Coroa de Proteína , Ouro , Humanos , Lasers , Análise Espectral
4.
Talanta ; 235: 122780, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517638

RESUMO

Archaeological sites often contain accumulations of remains derived from different independent events produced by different agents. Thus, in Palaeolithic sites, it is normal to find alternating occupations between humans and carnivores. The faunal assemblages at these sites usually include hundreds or thousands of bone fragments, which are very difficult to associate them to specific individuals since there are no currently available techniques able to do it in a straightforward and cost-effective way. In this work we present a methodology that allows us to characterise the anatomical remains of a bone accumulation and relate them all back to the specific individuals to which they belong. In order to provide a real world application, we have used a selection of animal bones from different individuals belonging to deer and sheep (fed in a controlled way using the same diet). On the other hand, fossilized faunal remains have also been analysed to verify if these fossilized bones keep some of the fingerprinting of the animal from which they come from. For this purpose, we have developed a protocol using Laser Induced Breakdown Spectroscopy (LIBS) together with Neural Networks (NN) implemented here to discriminate and reassemble deer and sheep bones from different individuals, which we subsequently applied for these proposes to fossilized material. To the best of our knowledge, this is the first time that this technique has been applied for individual fingerprinting to actuality and fossil samples. The elemental composition of bones provides enough information to get a correct discrimination of different individuals. The spectral correlation has exceeded 95 %. and all individuals were correctly classified to the individual from which they come from. There have been no instances of false positives or false negatives in our tests or applications.


Assuntos
Cervos , Fósseis , Animais , Arqueologia , Lasers , Ovinos , Análise Espectral
5.
Talanta ; 235: 122785, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517643

RESUMO

Elemental LA-ICPMS mapping in continuous scanning mode gathers the counts generated upon laser ablation in line scanning mode. Acquisition of counts can be performed for each single laser pulse separately or by summing the counts of multiple laser pulses. Conventionally, pixels in an LA-ICPMS map are associated with spot-resolved single laser pulses (zero-dimensional, 0D), but also sub-pixel convolution strategies are in use, associated with one-dimensional (1D) or two-dimensional (2D) overlapping laser shots, and where possible followed by deblurring. The imaging quality of several 0D, 1D, and 2D LA-ICPMS strategies were compared for mapping of (ultra)low-concentration samples, both via computational and experimental approaches. The data presented will be helpful to make the right decision about the best possible LA-ICPMS mapping strategy for the highest image quality.


Assuntos
Terapia a Laser , Lasers , Espectrometria de Massas , Análise Espectral
6.
Zhongguo Zhong Yao Za Zhi ; 46(15): 3873-3876, 2021 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-34472262

RESUMO

Compounds(1-6) were isolated and identified from 90% ethanol extract of the stems and leaves of Cassia occidentalis through column chromatography with silica gel, ODS, and Sephadex LH-20. These compounds were identified as 7-hydroxy-5-(3-hydroxy-2-oxopropyl)-2-methyl-4H-chromen-4-one(1), saccharonol A(2), S-6-hydroxymullein(3), 2-methyl-5-acetonyl-7-hydroxy-chromone(4), 2-(2'-hydroxypropyl)-5-methyl-7-hydroxychromone(5) and 7,4'-dihydroxyflavone(6) based on their physicochemical and spectroscopic data. Among them, compound 1 was a new compound, and all the compounds were isolated from this plant for the first time. DPPH method was employed to determine the antioxidant activities of these compounds in vitro. Six compounds exhibited weak antioxidant activities.


Assuntos
Senna (Planta) , Cromonas , Folhas de Planta , Análise Espectral
7.
Anal Chim Acta ; 1178: 338805, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34482864

RESUMO

The development of real-time monitoring sensors for pyro-metallurgical processes is an analytical challenge, mainly due to adverse environmental conditions, high spectral interferences and multiphase (molten and gas) reactions. This work demonstrates the suitability of stand-off LIBS (ST-LIBS) for real time monitoring of the desulfurization of blister copper which is carried out in molten phase. Here sulfur is removed by the formation of SO2 by supplying oxygen in molten phase. Using ST-LIBS the relative emission intensities of Cu(I) at 351.06 nm, O at 777.34 nm and S at 921.29 nm in both molten and gaseous phase were considered simultaneously during the process. This was possible only by the use high energy laser pulse over up to 270 mJ per pulse. In the case of copper, the selection of emission lines was assessed considering non-linear behavior, which is caused by self-absorption. For the first time, real time determination of sulfur in ppm range is reported by ST-LIBS using low sensitive lines from the NIR region. These results were validated with differential optical absorption spectroscopy (DOAS) as gold standard method. The analytical information obtained by LIBS can precisely determine the critical end-point of the desulfurization where the removal of sulfur is finished, and copper started to oxidize.


Assuntos
Vesícula , Cobre , Humanos , Lasers , Análise Espectral , Enxofre
8.
Anal Chim Acta ; 1178: 338799, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34482868

RESUMO

In this study, a simple and effective method for accurate determination of lithium in brine samples was developed by the combination of laser induced breakdown spectroscopy (LIBS) and convolutional neural network (CNN). Our results clearly demonstrate that the use of CNN could efficiently overcome the complex matrix effects, and thus allows for on-site Li quantitative determination in brine samples by LIBS. Specifically, two CNN models with different input data (M-CNN with matrix emission lines, and DP-CNN with double Li lines) were constructed based on the primary matrix features on spectrum and Boltzmann equation, respectively. It was observed that DP-CNN model could greatly improve the accuracy of Li analysis. We also compared the quantitative analysis capabilities of DP-CNN model with partial least squares regression (PLSR) and principal component analysis-support vector regression (PCA-SVR) model, and the results clearly showed DP-CNN offers the best quantification results (higher accuracy and less matrix interference). Finally, five real brine samples were successfully analyzed by the proposed DP-CNN model, confirming by the average absolute error of the prediction of 0.28 mg L-1 and the average relative error of 3.48%. These results clearly demonstrate that input data plays an important role in the training of CNN model in LIBS analysis, and the proposed DP-CNN provides an effective approach to solve the matrix effects encountered in LIBS for Li measurement in brine samples.


Assuntos
Lítio , Redes Neurais de Computação , Lasers , Sais , Análise Espectral
9.
Anal Chim Acta ; 1177: 338797, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34482885

RESUMO

Single cell - tandem ICP-mass spectrometry (SC-ICP-MS/MS) was used for the determination of the absolute amount of Pt (coming from exposure to various concentration levels of cisplatin as a chemotherapeutic drug) and five endogenous elements (P, S, Fe, Cu and Zn) in individual human cells of three different types - Raji, Jurkat and Y79. Optimum conditions were obtained by using a sample introduction unit transporting cell suspension containing approx. 5 × 104 cells per mL at a flow rate of 10 µL min-1 to a nebulizer with narrow internal diameter (250 µm i.d.), mounted onto a total consumption spray chamber. Interference-free conditions were obtained in tandem MS mode (i) for P and S by pressurizing the collision/reaction cell (CRC) with O2 and monitoring the PO+ and SO + reaction product ions and (ii) for Fe by pressurizing the CRC with NH3 and monitoring the Fe(NH3)2+ reaction product ion. The quantification approach was validated by comparison of the absolute amounts of the target elements (in fg per cell) as obtained using SC-ICP-MS/MS with those obtained after acid digestion of approx. 2 × 106 cells and subsequent solution ICP-MS/MS analysis ("bulk" analysis). A higher Pt cell content was observed upon increasing the concentration of the cisplatin solution the cells were exposed to during 24 h. The Pt mass per cell (fg) increased linearly as a function of the cisplatin concentration, but a higher Pt uptake was found in the case of Jurkat cells compared to the other cell types. A cell viability assay showed a lack of chemosensitivity to cisplatin below 200 µM for the Raji and Y79 cell line, but an IC50 value of 11.1 ± 1.3 µM for Jurkat cells. This difference in chemo-responsiveness between the different cell types supported the difference in Pt uptake as indicated via SC-ICP-MS analysis. The increasing level of Pt did not have a marked effect on the contents of the endogenous elements monitored in Raji and Y79 cells, but a decrease in the P and S cell content upon increasing cisplatin treatment was observed for Jurkat cells. This can most likely be attributed to stress induced by the chemotherapeutic treatment in cells showing chemosensitivity towards cisplatin. The results also indicate differences in the absolute amount of endogenous element per cell between different cell types, suggesting the potential of SC-ICP-MS as a "metallo-fingerprinting" tool.


Assuntos
Preparações Farmacêuticas , Espectrometria de Massas em Tandem , Cisplatino , Humanos , Análise Espectral
10.
Artigo em Chinês | MEDLINE | ID: mdl-34488272

RESUMO

Objective: To establish a direct dilution-inductively coupled plasma mass spectrometry method for the determination of manganese in urine. Methods: Using 1% nitric acid solution as diluent, the urine dilution factor and internal standard elements were determined by single factor rotation experiment. The linear range, correlation coefficient, precision, accuracy and detection limit of the direct dilution-inductively coupled plasma mass spectrometry for the determination of manganese in urine were evaluated. Results: The linear range of this method was 0.0-20 µg/L, the correlation coefficient was 0.999 9, the detection limit was 0.02 µg/L, the recoveries were 84.65%-103.40%, the relative standard deviations were 0.26%-8.17%. Conclusion: This method has the advantages of simple operation, high sensitivity and low detection limit. It can be used for the determination of urine manganese at the same time with other elements. It is suitable for the determination of urine manganese in workers and ordinary people.


Assuntos
Manganês , Ácido Nítrico , Humanos , Íons , Espectrometria de Massas , Análise Espectral
11.
Anal Methods ; 13(34): 3829-3836, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34374388

RESUMO

Internal standard lines play a crucial role in the univariate quantitative analysis in portable laser-induced breakdown spectroscopy (LIBS) technology. To overcome the uncertainty of the conventional internal standard method, the distribution principles of high-quality internal standard lines were studied and revealed at the macro and micro levels, and an automatic internal standard line selection method based on the Q-value was proposed. Using this method, in the quantitative analysis of Si in low-alloy steel samples, the average relative error of cross-validation (ARECV), root mean squared error of cross-validation (RMSECV), and the limit of detection (LoD) were decreased significantly from 27.42%, 0.041 wt%, and 1060 µg g-1 to 18.65%, 0.026 wt%, and 680 µg g-1, respectively. The quantitative analysis results of Cr, Cu and Ni showed that it has excellent generalization ability. The results indicate that this method can screen out the optimal internal standard lines efficiently and accurately, which provides a new approach to improve the performance of univariate quantitative analysis in portable LIBS.


Assuntos
Lasers , Aço , Análise Espectral
12.
J Agric Food Chem ; 69(34): 9979-9990, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34414767

RESUMO

In this work, we show the potential of single-particle inductively coupled plasma-mass spectrometry (spICP-MS) as a screening technique for detection of inorganic nanoparticles (NPs) that are expected to be present in food. We demonstrate that the spICP-MS/MS method in combination with collision/reaction cell gases and microsecond dwell times offers sensitive and interference-free detection of NPs. We present the steps that have to be considered to correctly assess the presence of NPs in food, for example, setting a suitable threshold for discriminating particle events from the baseline and analyzing a sufficient number of blank samples to minimize false-positive results. We applied the proposed screening approach to the sequential detection of NPs containing 8 selected elements that could be potentially present in 13 different food products. The highest mass concentrations of NPs (in the mg/g range) were found in the samples with food additives which are known to contain a fraction of NPs. The presence of (nano)particles in some of the investigated food samples was also confirmed by scanning electron microscopy analysis. Moreover, for the example of Al-containing NPs in Chinese noodles, we demonstrate that identification of the source of NPs with an unknown composition can be challenging when using only spICP-MS as particle mass concentration and size distribution can only be estimated by assuming a certain particle composition/shape. Other complementary techniques for particle characterization, such as electron microscopy in combination with elemental analysis, are therefore required.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Aditivos Alimentares , Tamanho da Partícula , Análise Espectral , Espectrometria de Massas em Tandem
13.
Spectrochim Acta A Mol Biomol Spectrosc ; 263: 120225, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34340052

RESUMO

In this study, highly reproducible MIR spectroscopy and highly sensitive MALDI-ToF-MS data were directly compared for the metabolomic profiling of monofloral and multifloral honey samples from three different botanical origins canola, acacia, and honeydew. Subsequently, three different classification models were applied to the data of both techniques, PCA-LDA, PCA- kNN, and soft independent modelling by class analogy (SIMCA) as class modelling technique. All monofloral external test set samples were classified correctly by PCA-LDA and SIMCA with both data sets, while multifloral test set samples could only be identified as outliers by the SIMCA technique, which is a crucial aspect in the authenticity control of honey. The comparison of the two used analytical techniques resulted in better overall classification results for the monofloral external test set samples with the MIR spectroscopic data. Additionally, clearly more multifloral external samples were identified as outliers by MIR spectroscopy (91.3%) as compared to MALDI-ToF-MS (78.3%). The results indicate that the high reproducibility of the used MIR technique leads to a generally better ability of separating monofloral honeys and in particular, identifying multifloral honeys. This demonstrates that benchtop-based techniques may operate on an eye-level with high-end laboratory-based equipment, when paired with an optimal data analysis strategy.


Assuntos
Mel , Flores , Mel/análise , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Análise Espectral
14.
Molecules ; 26(16)2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34443360

RESUMO

Plasma proteins play a fundamental role in living organisms. They participate in the transport of endogenous and exogenous substances, especially drugs. 5-alkyl-12(H)-quino[3,4-b][1,4]benzothiazinium salts, have been synthesized as potential anticancer substances used for cancer treatment. Most anticancer substances generate a toxic effect on the human body. In order to check the toxicity and therapeutic dosage of these chemicals, the study of ligand binding to plasma proteins is very relevant. The present work presents the first comparative analysis of the binding of one of the 5-alkyl-12(H)-quino[3,4-b][1,4]benzothiazinium derivatives (Salt1) with human serum albumin (HSA), α-1-acid glycoprotein (AGP) and human gamma globulin (HGG), assessed using fluorescence, UV-Vis and CD spectroscopy. In order to mimic in vivo ligand-protein binding, control normal serum (CNS) was used. Based on the obtained data, the Salt1 binding sites in the tertiary structure of all plasma proteins and control normal serum were identified. Both the association constants (Ka) and the number of binding site classes (n) were calculated using the Klotz method. The strongest complex formed was Salt1-AGPcomplex (Ka = 7.35·104 and 7.86·104 mol·L-1 at excitation wavelengths λex of 275 and 295 nm, respectively). Lower values were obtained for Salt1-HSAcomplex (Ka = 2.45·104 and 2.71·104 mol·L-1) and Salt1-HGGcomplex (Ka = 1.41·104 and 1.33·104 mol·L-1) at excitation wavelengths λex of 275 and 295 nm, respectively, which is a positive phenomenon and contributes to the prolonged action of the drug. Salt1 probably binds to the HSA molecule in Sudlow sites I and II; for the remaining plasma proteins studied, only one binding site was observed. Moreover, using circular dichroism (CD), fluorescence and UV-Vis spectroscopy, no effect on the secondary and tertiary structures of proteins in the absence or presence of Salt1 has been demonstrated. Despite the fact that the conducted studies are basic, from the scientific point of view they are novel and encourage further in vitro and in vivo investigations. As a next part of the study (Part 2), the second new synthetized quinobenzothiazine derivative (Salt2) will be analyzed and published.


Assuntos
Proteínas Sanguíneas/metabolismo , Análise Espectral , Tiazinas/química , Tiazinas/metabolismo , Proteínas Sanguíneas/química , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica , Conformação Proteica , Termodinâmica
15.
Molecules ; 26(16)2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34443568

RESUMO

Laser-Induced Breakdown Spectroscopy (LIBS), having reached a level of maturity during the last few years, is generally considered as a very powerful and efficient analytical tool, and it has been proposed for a broad range of applications, extending from space exploration down to terrestrial applications, from cultural heritage to food science and security. Over the last decade, there has been a rapidly growing sub-field concerning the application of LIBS for food analysis, safety, and security, which along with the implementation of machine learning and chemometric algorithms opens new perspectives and possibilities. The present review intends to provide a short overview of the current state-of-the-art research activities concerning the application of LIBS for the analysis of foodstuffs, with the emphasis given to olive oil, honey, and milk.


Assuntos
Produtos Biológicos/química , Análise de Alimentos/métodos , Mel/análise , Lasers , Leite/química , Azeite de Oliva/química , Análise Espectral , Animais
16.
Analyst ; 146(17): 5389-5402, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34346415

RESUMO

This study reports novel approaches for the detection of gunshot residues (GSR) from the hands of individuals using Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). The methods' performance was evaluated using 159 GSR standard and authentic samples. Forty specimens generated from characterized microparticles were used as matrix-matched primer gunshot residue (pGSR) standards to examine the elemental profiles of leaded and lead-free residues, compared to SEM-EDS and solution-ICP-MS. Also, 119 authentic skin samples were analyzed to estimate error rates. Shooter samples were correctly classified into three categories based on their elemental composition (leaded, lead-free, or mixed pGSR). A total of 60 non-shooter samples were used to establish background thresholds and estimate specificity (93.4% for LA-ICP-MS and 100% for LIBS). All the authentic leaded items resulted in the detection of particle(s) with composition characteristic of pGSR (Pb-Ba-Sb), as observed by simultaneous elemental identification of target analytes at the exact ablation times and locations. When considering the pre-characterized elemental composition of these primers as the "ground truth", LA-ICP-MS resulted in 91.8% sensitivity (true positive rate), while LIBS resulted in 89.2% sensitivity. Particles containing Ba, Bi, Bi-Cu-K, and Cu-Ti-Zn were found in the lead-free residues. Identification of lead-free GSR proved more challenging as some of these elements are common in the environment, resulting in 85.2% sensitivity for LA-ICP-MS and 44.4% for LIBS. Overall accuracies of 94.9% and 88.2% were obtained for the LA-ICP-MS and LIBS sets, respectively. LA-ICP-MS provided an additional level of confidence in the results by its superior analytical capabilities, complementing the LIBS chemical profiles. The laser-based methods provide rapid chemical profiling and micro-spatial information of gunshot residue particles, with minimal destruction of the sample and high accuracy. Chemical mapping of 25 micro-regions per sample is possible in 2-10 minutes by LIBS and LA-ICP-MS, offering new tools for more comprehensive forensic case management and quick GSR screening in environmental and occupational sciences.


Assuntos
Terapia a Laser , Medicina Legal , Humanos , Lasers , Espectrometria de Massas , Análise Espectral
17.
J Environ Sci (China) ; 107: 1-13, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34412773

RESUMO

Atmospheric aerosols have effects on atmospheric radiation assessments, global climate change, local air quality and visibility. In particular, aerosols are more likely transformed and accumulated in winter. In this paper, we used the Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) instrument to study the characteristics of aerosol type and contributions of PM2.5 chemical components to aerosol extinction (AE), vertical distribution of aerosols, and source. From December 30, 2018 to January 27, 2019, we conducted MAX-DOAS observations on Sanmenxia. The proportion of PM2.5 to PM10 was 69.48%-95.39%, indicating that the aerosol particles were mainly fine particles. By analyzing the ion data and modifying Interagency Monitoring of Protected Visual Environments (IMPROVE) method, we found that nitrate was the largest contributor to AE, accounting for 31.51%, 28.98%, and 27.95% of AE on heavily polluted, polluted, and clean days, respectively. NH4+, OC, and SO42- were also major contributors to AE. The near-surface aerosol extinction retrieved from MAX-DOAS measurement the PM2.5 and PM10 concentrations measured by an Unmanned Aerial Vehicle (UAV) have the same trend in vertical distribution. AE increased about 3 times from surface to 500 m. With the backward trajectory of the air mass during the haze, we also found that the continuous heavy pollution was mainly caused by transport of polluted air from the northeast, then followed by local industrial emissions and other sources of emissions under continuous and steady weather conditions.


Assuntos
Poluentes Atmosféricos , Aerossóis/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análise , Análise Espectral
18.
Zhongguo Zhong Yao Za Zhi ; 46(14): 3694-3704, 2021 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-34402294

RESUMO

The effects of Chloriti Lapis on metal elements in plasma and lung tissue of acute exacerbation of chronic obstructive pulmonary disease( AECOPD) rats were studied. The rat AECOPD model with phlegm heat syndrome was established by smoking combined with Klebsiella pneumoniae infection. After the rats were treated by Chloriti Lapis,the contents of metal elements in plasma and lung tissue were determined by inductively coupled plasma-optical emission spectroscopy( ICP-OES) and inductively coupled plasma mass spectrometry( ICP-MS). The changes in the contents of metal elements were analyzed by SPSS 18. 0. Further,the correlations of differential metal elements( including Cu/Zn ratio) with differential metabolites in plasma,lung tissue and urine of AECOPD rats treated with Chloriti Lapis were analyzed. The results showed that Chloriti Lapis significantly up-regulated the contents of Fe,Al,Mn,Cu,Zn,Sn( P<0. 05),V,Co( P< 0. 01) and Cu/Zn ratio( P< 0. 05),and significantly down-regulated the contents of Ti( P< 0. 05)and Pb( P<0. 05) in the model rat plasma. It significantly increased the content of Be( P<0. 05) and decreased the contents of Mg,Ti and Al( P<0. 01) in model rat lung tissue. The element profiles of normal group,model group and Chloriti Lapis group can be well separated. Chloriti Lapis group and other groups were clustered into two categories. The taurine in plasma and phytosphingosine in lung tissue had the strongest correlations with differential metal elements. The Fe,Al,Mg,Be,Ti,V,Mn,Cu,Zn,Sn,and Co in Chloriti Lapis may directly or indirectly participate in the intervention of AECOPD rats. This group of metal elements may be the material basis of Chloriti Lapis acting on AECOPD rats,and reduce the Cu/Zn value in vivo. It was further confirmed that Chloriti Lapis could interfere with the metabolic pathways of taurine and hypotaurine in plasma and urine as well as the sphingolipid metabolism pathway in lung tissue of AECOPD rats. In addition,this study confirmed that long-term smoking can cause high-concentration Cd accumulation in the lung and damage the lung tissue.


Assuntos
Doença Pulmonar Obstrutiva Crônica , Oligoelementos , Animais , Pulmão , Medicina Tradicional Chinesa , Minerais , Ratos , Análise Espectral , Oligoelementos/análise
19.
Methods Enzymol ; 657: 1-19, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34353483

RESUMO

Photoacoustic (PA) imaging is an emerging imaging modality that combines the advantages of optical imaging and ultrasound imaging. In particular, activatable PA probes, which visualize the presence or the activity of target molecules in terms of a change of the PA signal, are useful tools for functional imaging. In this chapter, we describe the development of small-molecule-based activatable PA probes, focusing on the design and synthesis of PA-MMSiNQ, our recently developed activatable PA probe for HOCl. We also describe the protocols used for evaluation of PA-MMSiNQ with a UV-vis spectrometer and a PA imaging microscope.


Assuntos
Técnicas Fotoacústicas , Imagem Molecular , Imagem Óptica , Análise Espectral
20.
Methods Enzymol ; 657: 157-180, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34353486

RESUMO

In this chapter, we introduce a two-phase tuning approach for developing highly sensitive photoacoustic probes for imaging nitric oxide (NO) in the near-infrared (NIR)-II window. Due to the synthetically challenging nature of current NIR-II dye platforms, our two-phase tuning approach circumvents this issue by first allowing one to tune the reactivity using a synthetically accessible dye. We have used a physical organic workflow to understand the reaction kinetics and identify the most reactive sensing component. The selected reactive trigger is then introduced to phase two where it is appended to a range of well-established NIR-II dyes. This strategy is used to select the ideal photoacoustic probe for NIR-II imaging in vivo. Here, we have detailed procedures for synthesis, in vitro studies, and in vivo imaging.


Assuntos
Técnicas Fotoacústicas , Corantes , Óxido Nítrico , Análise Espectral
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