Pub Date : 2023-01-01DOI: 10.56530/spectroscopy.mi9381w4
B. Smith
Acrylate polymers are derivatives of acrylic acid, but contain a plethora of different functional groups and are best discussed by themselves. In this column, we study the spectrum of an important polymer, polymethyl methacrylate (PMMA), which is otherwise known as plexiglass, and is found in windows, car parts, and paint. We then study the spectra of PMMA mixtures and copolymers in detail.
{"title":"Infrared Spectroscopy of Polymers X: Polyacrylates","authors":"B. Smith","doi":"10.56530/spectroscopy.mi9381w4","DOIUrl":"https://doi.org/10.56530/spectroscopy.mi9381w4","url":null,"abstract":"Acrylate polymers are derivatives of acrylic acid, but contain a plethora of different functional groups and are best discussed by themselves. In this column, we study the spectrum of an important polymer, polymethyl methacrylate (PMMA), which is otherwise known as plexiglass, and is found in windows, car parts, and paint. We then study the spectra of PMMA mixtures and copolymers in detail.","PeriodicalId":21957,"journal":{"name":"Spectroscopy","volume":"72 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76213367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.56530/spectroscopy.hu6980q3
J. Coates
In the past, moving from a concept for an analytical instrument to actually producing a functioning instrument was a relatively tedious and lengthy process. The traditional approach was to draft a design and then go through a number of iterations, along with design reviews and sign-offs. Today, if one has a good designer who is well-versed in computer-aided design (CAD) engineering software, then it is possible to significantly reduce the time to develop a good-looking functional design. However, the time to go from the CAD design to a complete piece of hardware is typically the longest part of the process. It is not unusual for machine shop delays to be up to 6–8 weeks. Today, such delays can be eliminated by producing the designed parts on a desktop with a three-dimensional (3D) printer. This article shows, by example, how a 3D printer can speed up the process of making prototype hardware for a spectral measurement system, shortening the time to produce functional hardware from weeks to days—or less.
{"title":"Three-Dimensional Printing and the Art of Making Small Working Prototype Spectrometers","authors":"J. Coates","doi":"10.56530/spectroscopy.hu6980q3","DOIUrl":"https://doi.org/10.56530/spectroscopy.hu6980q3","url":null,"abstract":"In the past, moving from a concept for an analytical instrument to actually producing a functioning instrument was a relatively tedious and lengthy process. The traditional approach was to draft a design and then go through a number of iterations, along with design reviews and sign-offs. Today, if one has a good designer who is well-versed in computer-aided design (CAD) engineering software, then it is possible to significantly reduce the time to develop a good-looking functional design. However, the time to go from the CAD design to a complete piece of hardware is typically the longest part of the process. It is not unusual for machine shop delays to be up to 6–8 weeks. Today, such delays can be eliminated by producing the designed parts on a desktop with a three-dimensional (3D) printer. This article shows, by example, how a 3D printer can speed up the process of making prototype hardware for a spectral measurement system, shortening the time to produce functional hardware from weeks to days—or less.","PeriodicalId":21957,"journal":{"name":"Spectroscopy","volume":"147 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86202514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.56530/spectroscopy.kj3680j3
J. Dubrovkin, V. Tomin, A. Krzysztofowicz
A new method based on singular value decomposition (SVD) was applied to the denoising of the time-resolved spectral matrix (TRSM), which was obtained by a streak camera. The least informative principal components (PCs) were filtered out using the Tikhonov regularization principle. A method for determining the quasi-optimal regularization parameter was suggested. The SVD method was compared with the moving average time direction (MATD) smoothing of the TRSM. Numerical simulations and experimental study of the 3-aminophthalimide (3AP) solution in acetonitrile showed that the SVD smoothing allowed for accurate measurement of signals in peak maximum. Fitting the polynomial modified Gaussian to the smoothed fluorescent bands decreased the measurement errors of the maximum peak position and its width. This method allowed us to obtain kinetics data of the fluorescence band parameters of the 3AP spectrum in an acetonitrile solution. Flexible selection of the quasi-optimal processing parameters and a better time resolution are the main advantages of the SVD method over MATD.
{"title":"Smoothing of the Time-Resolved Spectral Matrix Obtained by a Streak Camera: Estimation of the Fluorescence Band Parameters","authors":"J. Dubrovkin, V. Tomin, A. Krzysztofowicz","doi":"10.56530/spectroscopy.kj3680j3","DOIUrl":"https://doi.org/10.56530/spectroscopy.kj3680j3","url":null,"abstract":"A new method based on singular value decomposition (SVD) was applied to the denoising of the time-resolved spectral matrix (TRSM), which was obtained by a streak camera. The least informative principal components (PCs) were filtered out using the Tikhonov regularization principle. A method for determining the quasi-optimal regularization parameter was suggested. The SVD method was compared with the moving average time direction (MATD) smoothing of the TRSM. Numerical simulations and experimental study of the 3-aminophthalimide (3AP) solution in acetonitrile showed that the SVD smoothing allowed for accurate measurement of signals in peak maximum. Fitting the polynomial modified Gaussian to the smoothed fluorescent bands decreased the measurement errors of the maximum peak position and its width. This method allowed us to obtain kinetics data of the fluorescence band parameters of the 3AP spectrum in an acetonitrile solution. Flexible selection of the quasi-optimal processing parameters and a better time resolution are the main advantages of the SVD method over MATD.","PeriodicalId":21957,"journal":{"name":"Spectroscopy","volume":"16 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90166799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-01DOI: 10.56530/spectroscopy.sc1575j6
F. Adar
In a follow-up to my February 2020 column, I started a more systematic study of extractables and leachables. Following a suggestion from Mark Witkowski of the FDA, I looked at three sets of centrifuge vials that were exposed to the following liquids in an effort to evaluate the potential of Raman microscopy to identify compounds exiting in polymers under particular conditions: saline, phosphate buffer, water, saline treatment at 100 0C, phosphate buffer treatment at 100 0C, water treatment at 100 0C, ethanol, chloroform, pH 5, and pH 9. Although all containers were made of polypropylene (PP), they didn’t behave similarly. Compounds that were extracted from PP vials from different manufacturers were not always the same. Although the number of spectral types that are recorded is large, this article focuses on a few whose interpretation is interesting. The goal was to figure out when it makes sense to employ Raman microscopy for such identification. The characteristics considered were ease of sample preparation, the minimum quantity of material amenable to analysis, and the quality of the identification.
{"title":"Exploration of the Use of Raman Microscopy to the Identification of Extractables and Leachables from Polymeric Containers","authors":"F. Adar","doi":"10.56530/spectroscopy.sc1575j6","DOIUrl":"https://doi.org/10.56530/spectroscopy.sc1575j6","url":null,"abstract":"In a follow-up to my February 2020 column, I started a more systematic study of extractables and leachables. Following a suggestion from Mark Witkowski of the FDA, I looked at three sets of centrifuge vials that were exposed to the following liquids in an effort to evaluate the potential of Raman microscopy to identify compounds exiting in polymers under particular conditions: saline, phosphate buffer, water, saline treatment at 100 0C, phosphate buffer treatment at 100 0C, water treatment at 100 0C, ethanol, chloroform, pH 5, and pH 9. Although all containers were made of polypropylene (PP), they didn’t behave similarly. Compounds that were extracted from PP vials from different manufacturers were not always the same. Although the number of spectral types that are recorded is large, this article focuses on a few whose interpretation is interesting. The goal was to figure out when it makes sense to employ Raman microscopy for such identification. The characteristics considered were ease of sample preparation, the minimum quantity of material amenable to analysis, and the quality of the identification.","PeriodicalId":21957,"journal":{"name":"Spectroscopy","volume":"275 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76514125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-01DOI: 10.56530/spectroscopy.ag1869d9
Kaiyu Zhang, Yuxin Sang, Qinxing Sun, Weina Li
In this study, a colorimetric discrimination of Pd2+ and Hg2+ ions in the solvent and solid film states in one silver nanoparticles (AgNPs) sensing system is presented. First, silver nanoparticles were prepared by reducing AgNO3 with sodium borohydride in the presence of chitosan and different organic acids, including acetic acid, propanedioic acid, and citric acid. The addition of different organic acids allowed for the surface plasmon resonance (SPR) intensity and size distribution of AgNPs to be adjusted. Chitosan acts as a stabilizer and complexing agent, endowing AgNPs excellent film-forming properties. Then, the chitosan-stabilized AgNPs in the solvent and solid-film state are used to detect metal ions. In the presence of Hg2+ and Pd2+ ions, the color of the AgNP solution changed rapidly from pale yellow to colorless and light brown, respectively. The characteristic SPR peaks of the AgNPs also disappeared completely, and the solid films of AgNPs with a yellowish-brown color also change rapidly to colorless and dark brown with the addition of Hg2+ and Pd2+ ions, respectively. The discrimination of Hg2+ and Pd2+ ions can be clearly observed in both the solvent and the solid film state. However, the addition of other metal ions cannot change the color of the AgNPs.
{"title":"Colorimetric Discrimination of Pd2+ and Hg2+ Ions in Solvent and Solid-Film State Using Organic Acid-Assisted Green Synthesized Silver Nanoparticles","authors":"Kaiyu Zhang, Yuxin Sang, Qinxing Sun, Weina Li","doi":"10.56530/spectroscopy.ag1869d9","DOIUrl":"https://doi.org/10.56530/spectroscopy.ag1869d9","url":null,"abstract":"In this study, a colorimetric discrimination of Pd2+ and Hg2+ ions in the solvent and solid film states in one silver nanoparticles (AgNPs) sensing system is presented. First, silver nanoparticles were prepared by reducing AgNO3 with sodium borohydride in the presence of chitosan and different organic acids, including acetic acid, propanedioic acid, and citric acid. The addition of different organic acids allowed for the surface plasmon resonance (SPR) intensity and size distribution of AgNPs to be adjusted. Chitosan acts as a stabilizer and complexing agent, endowing AgNPs excellent film-forming properties. Then, the chitosan-stabilized AgNPs in the solvent and solid-film state are used to detect metal ions. In the presence of Hg2+ and Pd2+ ions, the color of the AgNP solution changed rapidly from pale yellow to colorless and light brown, respectively. The characteristic SPR peaks of the AgNPs also disappeared completely, and the solid films of AgNPs with a yellowish-brown color also change rapidly to colorless and dark brown with the addition of Hg2+ and Pd2+ ions, respectively. The discrimination of Hg2+ and Pd2+ ions can be clearly observed in both the solvent and the solid film state. However, the addition of other metal ions cannot change the color of the AgNPs.","PeriodicalId":21957,"journal":{"name":"Spectroscopy","volume":"27 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85430068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-01DOI: 10.56530/spectroscopy.nj6365j3
Jerry Workman
In this Part 4 survey article describing instrument services and testing, we look into spectroscopy electronics, including printed circuit board (PCB) design and manufacturing, a description of spectroscopy instrument design services, a summary of instrument testing services, and a description of the firmware and software aspects of instrumentation. This is the final installment of our four-part instrument component survey series. As promised, we have published tutorial articles, and posted the The Spectroscopy Instrument Components Terminology Guide. We hope our readers found these articles helpful for our “under the hood” look into spectroscopy instrumentation.
{"title":"A Survey of Basic Instrument Components Used in Spectroscopy, Part 4: Instrument Services and Testing","authors":"Jerry Workman","doi":"10.56530/spectroscopy.nj6365j3","DOIUrl":"https://doi.org/10.56530/spectroscopy.nj6365j3","url":null,"abstract":"In this Part 4 survey article describing instrument services and testing, we look into spectroscopy electronics, including printed circuit board (PCB) design and manufacturing, a description of spectroscopy instrument design services, a summary of instrument testing services, and a description of the firmware and software aspects of instrumentation. This is the final installment of our four-part instrument component survey series. As promised, we have published tutorial articles, and posted the The Spectroscopy Instrument Components Terminology Guide. We hope our readers found these articles helpful for our “under the hood” look into spectroscopy instrumentation.","PeriodicalId":21957,"journal":{"name":"Spectroscopy","volume":"27 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90779094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-01DOI: 10.56530/spectroscopy.xn9369p8
B. Smith
We continue our survey of the spectra of carbonyl-containing polymers by looking at the spectrum of cellulose acetate. What makes cellulose acetate unique is that it is a carbohydrate molecule that is reacted to obtain pendant ester groups. I will also introduce you to polycarbonates. Carbonates are a carbonyl-containing functional group that contain three oxygen atoms. An example of an economically important polycarbonate is Lexan, which is made into windows and car parts. In this column, we examine its spectrum in detail.
{"title":"Infrared Spectroscopy of Polymers, IX: Pendant Ester Polymers and Polycarbonates","authors":"B. Smith","doi":"10.56530/spectroscopy.xn9369p8","DOIUrl":"https://doi.org/10.56530/spectroscopy.xn9369p8","url":null,"abstract":"We continue our survey of the spectra of carbonyl-containing polymers by looking at the spectrum of cellulose acetate. What makes cellulose acetate unique is that it is a carbohydrate molecule that is reacted to obtain pendant ester groups. I will also introduce you to polycarbonates. Carbonates are a carbonyl-containing functional group that contain three oxygen atoms. An example of an economically important polycarbonate is Lexan, which is made into windows and car parts. In this column, we examine its spectrum in detail.","PeriodicalId":21957,"journal":{"name":"Spectroscopy","volume":"71 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76335946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-01DOI: 10.56530/spectroscopy.lz8466z5
Richard A. Crocombe
This article gives a brief overview of the major portable techniques: those based on optical spectroscopy techniques, including near-infrared (NIR), mid-infrared (mid-IR), and Raman spectroscopy; mass spectrometry (MS) systems, including high-pressure MS (HPMS), gas chromatography–MS (GC–MS), ion mobility spectrometry (IMS); elemental techniques, such as X-ray fluorescence (XRF) and laser-induced breakdown spectroscopy (LIBS); and emerging miniaturized techniques like nuclear magnetic resonance (NMR). The above are all “conventional” spectroscopic techniques and reduced to a rugged portable format, containing self-contained data systems. They provide specific and actionable information to their operators working with them outside the laboratory—in the field—and these instruments have well-defined value propositions. A recent development is the availability of low cost (<$100) multispectral sensors operating in the visible and NIR regions. This low cost enables the sensors to be embedded into consumer products, such as smart “white goods” appliances, personal care, fitness products, and even “wearables” products. In the future, miniature and portable spectrometers will be ubiquitous—outside the laboratory, and in your home and pocket.
{"title":"Spectrometers in Wonderland: Shrinking, Shrinking, Shrinking","authors":"Richard A. Crocombe","doi":"10.56530/spectroscopy.lz8466z5","DOIUrl":"https://doi.org/10.56530/spectroscopy.lz8466z5","url":null,"abstract":"This article gives a brief overview of the major portable techniques: those based on optical spectroscopy techniques, including near-infrared (NIR), mid-infrared (mid-IR), and Raman spectroscopy; mass spectrometry (MS) systems, including high-pressure MS (HPMS), gas chromatography–MS (GC–MS), ion mobility spectrometry (IMS); elemental techniques, such as X-ray fluorescence (XRF) and laser-induced breakdown spectroscopy (LIBS); and emerging miniaturized techniques like nuclear magnetic resonance (NMR). The above are all “conventional” spectroscopic techniques and reduced to a rugged portable format, containing self-contained data systems. They provide specific and actionable information to their operators working with them outside the laboratory—in the field—and these instruments have well-defined value propositions. A recent development is the availability of low cost (<$100) multispectral sensors operating in the visible and NIR regions. This low cost enables the sensors to be embedded into consumer products, such as smart “white goods” appliances, personal care, fitness products, and even “wearables” products. In the future, miniature and portable spectrometers will be ubiquitous—outside the laboratory, and in your home and pocket.","PeriodicalId":21957,"journal":{"name":"Spectroscopy","volume":"176 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73529167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-01DOI: 10.56530/spectroscopy.yd5989g6
F. Ou, A. van Klinken, K. Hakkel, M. Petruzzella, Don M. J. van Elst, P. Sevo, Chenhui Li, F. Pagliano, R. V. van Veldhoven, A. Fiore
Near-infrared (NIR) spectroscopy is widely used for the classification of materials and the quantification of their properties. Today, there is a high demand for extending the use of this technique to portable applications, and eventually, the integration with consumer appliances and smartphones. To reach this goal, the overall size of the NIR sensor, its production cost, robustness, and resistance to vibrations are of particular importance. This paper describes an approach to spectral sensing in the NIR (850–1700 nm) using a handheld sensor module based on a fully integrated multipixel detector array with a footprint of around 2×2 mm2. The capabilities of the spectral sensor module were recently evaluated in two application cases: Quantification of the fat percentage in raw milk and the classification of plastic types. Fat quantification was achieved with a root mean square error (RMSE) of prediction of 0.14% and classification of plastic types was achieved with a prediction accuracy on unknown samples of 100%. The results demonstrate the feasibility of the direct NIR sensing approach used by the integrated sensor, which has potential to be used in a variety of applications.
{"title":"Spectral Sensing Using a Handheld NIR Module Based on a Fully Integrated Sensor Chip","authors":"F. Ou, A. van Klinken, K. Hakkel, M. Petruzzella, Don M. J. van Elst, P. Sevo, Chenhui Li, F. Pagliano, R. V. van Veldhoven, A. Fiore","doi":"10.56530/spectroscopy.yd5989g6","DOIUrl":"https://doi.org/10.56530/spectroscopy.yd5989g6","url":null,"abstract":"Near-infrared (NIR) spectroscopy is widely used for the classification of materials and the quantification of their properties. Today, there is a high demand for extending the use of this technique to portable applications, and eventually, the integration with consumer appliances and smartphones. To reach this goal, the overall size of the NIR sensor, its production cost, robustness, and resistance to vibrations are of particular importance. This paper describes an approach to spectral sensing in the NIR (850–1700 nm) using a handheld sensor module based on a fully integrated multipixel detector array with a footprint of around 2×2 mm2. The capabilities of the spectral sensor module were recently evaluated in two application cases: Quantification of the fat percentage in raw milk and the classification of plastic types. Fat quantification was achieved with a root mean square error (RMSE) of prediction of 0.14% and classification of plastic types was achieved with a prediction accuracy on unknown samples of 100%. The results demonstrate the feasibility of the direct NIR sensing approach used by the integrated sensor, which has potential to be used in a variety of applications.","PeriodicalId":21957,"journal":{"name":"Spectroscopy","volume":"20 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88056539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-01DOI: 10.56530/spectroscopy.cs9787u9
Megan Wilson, D. Al-Jumeily, J. Birkett, Iftikhar Khan, Ismail Abbas, S. Assi
Fingernails can accumulate drugs as a result of chronic exposure. This work employed Raman spectroscopy for detecting cocaine hydrochloride (HCl) and its impurities within fingernails, utilizing orbital raster scanning (ORS) technology, where the laser beam hits multiple positions within the sample. Doing so maintained sensitivity and ensured that more of each sample’s components were represented. Fingernails were spiked with powder and solution forms of cocaine HCl and its impurities, including benzocaine HCl, levamisole HCl, lidocaine HCl, and procaine HCl. The strong Raman scattering observed for these substances indicated a high drug accumulation in the fingernails. Key cocaine HCl bands were seen at 848, 874, and 898 cm-1 (C-C stretching-tropane ring), 1004 cm-1 (symmetric stretching-aromatic ring), 1278 cm-1 (C-N stretching), 1453 cm-1 (asymmetric CH3 deformation), and 1605 and 1712 cm-1 (C=C and C=O stretching). Principal components analysis (PCA) confirmed that 90% (nails spiked with drug powders) and 77.2% (nails spiked with drug solutions) were accounted for in the variance among the data. The findings showed that Raman spectroscopy identified the presence of cocaine HCl and its impurities within fingernails.
{"title":"Using Handheld Raman Spectroscopy Equipped with Orbital Raster Technology for Field Detection of Cocaine and its Impurities in Fingernails","authors":"Megan Wilson, D. Al-Jumeily, J. Birkett, Iftikhar Khan, Ismail Abbas, S. Assi","doi":"10.56530/spectroscopy.cs9787u9","DOIUrl":"https://doi.org/10.56530/spectroscopy.cs9787u9","url":null,"abstract":"Fingernails can accumulate drugs as a result of chronic exposure. This work employed Raman spectroscopy for detecting cocaine hydrochloride (HCl) and its impurities within fingernails, utilizing orbital raster scanning (ORS) technology, where the laser beam hits multiple positions within the sample. Doing so maintained sensitivity and ensured that more of each sample’s components were represented. Fingernails were spiked with powder and solution forms of cocaine HCl and its impurities, including benzocaine HCl, levamisole HCl, lidocaine HCl, and procaine HCl. The strong Raman scattering observed for these substances indicated a high drug accumulation in the fingernails. Key cocaine HCl bands were seen at 848, 874, and 898 cm-1 (C-C stretching-tropane ring), 1004 cm-1 (symmetric stretching-aromatic ring), 1278 cm-1 (C-N stretching), 1453 cm-1 (asymmetric CH3 deformation), and 1605 and 1712 cm-1 (C=C and C=O stretching). Principal components analysis (PCA) confirmed that 90% (nails spiked with drug powders) and 77.2% (nails spiked with drug solutions) were accounted for in the variance among the data. The findings showed that Raman spectroscopy identified the presence of cocaine HCl and its impurities within fingernails.","PeriodicalId":21957,"journal":{"name":"Spectroscopy","volume":"4 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86943382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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