overview of raman spectroscopy and b&w tek portable ... · •positioning of portable raman vs...

Overview of Raman Spectroscopy and B&W Tek Portable Instruments

and Applications

May 2016

www.bwtek.com 1 Copyright 2016 B&W Tek

Outline • Raman Spectroscopy • Positioning of Portable Raman vs NanoRam® • B&W Tek Portable Raman Systems

– Portable Raman Systems – Sampling and Accessories – Raman Software: BWID®, BWSpec® and BWIQ®

• Raman Applications


RAMAN SPECTROSCOPY


What is Raman Spectroscopy? • Raman spectroscopy is a form of molecular spectroscopy – the

scattering of electromagnetic radiation by atoms or molecules. The Raman signal is observed as inelastically scattered light and is an invaluable tool for molecular fingerprinting.

– Advantages of Raman Spectroscopy – Little to no sample preparation required – Perform analysis directly through transparent or translucent containers – (i.e. plastic bags, glass, etc.) – Enables both qualitative and quantitative analysis – Highly selective – Fast analysis times – Insensitive to aqueous absorption bands

KEY: Sensitivity, S/N, performance/cost, reproducibility, qualitative/quantitative


Portable Raman Applications Art and archaeology

Forensic analysis

Academic research & teaching

Carbon materials characterization

Pharmaceutical & chemical QC lab

Bioscience & medical diagnosis

Materials science

7 Copyright 2016 B&W Tek www.bwtek.com

Polymorph detection

Raman Applicability • Raman has greater selectivity to symmetric vibrations present in

aromatic molecules, -S-S- bonds, C=C bonds, etc. • Due to the relative strength of Raman scattering of aromatic compounds

found in many drug substances compared to nonaromatic excipients, it provides some selectivity for analysis of an API in pharmaceutical products

• Can be used for nondestructive, noncontact analysis through packaging • Is compatible for use with fiber optics


Laser 785 nm Excitation

1,000,000 photon vs.1

Raman Scattering


Raman Spectrum

www.bwtek.com 10

A Raman spectrum is a plot of the intensity of Raman scattered radiation as a function of its frequency difference from the incident radiation (usually in units of wavenumbers, cm-1). This difference is called the Raman shift.

µν K

m ∝

(CC) Aliphatic Ring

(CC) Aromatic Ring

C=C δ C-C aliphatic

CH2 asym

ν C-C aliphatic

Copyright 2016 B&W Tek

Raman Spectral Information

www.bwtek.com 11

500 1000 1500 2000 2500 3000 Raman Shift (cm-1)

(CH3)2C=O

CH3CH2OH

(CH3)2S=O

CH3CH2O2CCH3

C6H5CH3

C=O

C=O CH3

Aromatic-H

S=O

CH3 CH2 C-O

CH3 Aromatic


Raman Limitations

• Weak signal (efficiency ~ 10-8): typical limit of detection (LOD) ~1% – SERS (Surface-enhance Raman ) can be used to increase signal by ~ 106

• Fluorescence interference – choose longer wavelength excitation laser • Sample heating or photobleaching can interfere; challenge with black or deeply

colored materials • High information content (interferences) • Laser source may have fluctuations • Need an internal standard or standardization (normalization) for quantitative

work


Raman Diagram A Raman Instrument consists of a laser, sampling optics (probe), and an optical spectrometer. Because of very weak Raman scattering signals lasers are used as intense excitation sources.


Sampling • Fiber optic probes can be easily

adapted to a variety of different sampling configurations

– Liquid flow cells – Gas flow cells – Optical microscopes – Probe holder – Cuvette or vial holder – Tripod for use with video

microscope


Excitation Wavelengths


B&W Tek’s Portable Raman Spectrometers • Rugged design • No moving parts for reliability • Small size for full portability allowing for on site

analysis • Light weight • Fiber probe for easy sampling • Battery option • High performance to cost ratio

www.bwtek.com 17

i-Raman® used for geological

studies in Sverrefjell Volcano, Norway

Ref: A. Dominguez-Vidal et al, Analyst, 2012, 137(24), 5763. Reproduced with permission of the RSC


PORTABLE RAMAN INSTRUMENTATION


i-Raman® Plus • Lightweight, portable Raman

spectrometer with research-grade performance

• Portability makes it ideal for field work, and also for process/product development work – which may need to be done in different laboratories

• High performance for use in research applications – including materials structural elucidation, sample identification, Raman microscopy

• Qualitative and quantitative analysis including reaction monitoring, polymorph content

• Product identification and counterfeit detection


i-Raman® Plus Technical Specifications • 532 or 785 nm excitation laser options • Class 3B laser with 320 mW max laser

power (785 nm ) adjustable to 1% increments

• Resolution better than 4.5 cm-1 Spectral range

– 532 nm options from 65-4200 cm-1

– 785 nm options form 65-3350 cm-1

– Thermoelectrically cooled 2048 element CCD array detector

– Dynamic range: 50,000:1 – Integration time 100 ms to 30 minutes – Weight: 6.6 lbs (~ 3 kg)


i-Raman® Plus • Small footprint, lightweight, low power

consumption- excellent performance • Raman shift range up to 3350 cm-1

(4200 for 532 nm system) covering C-H stretching modes

• Comprehensive suite of accessories, and software, allow versatility and portability

• BWIQ® for quantitative analysis; • BWID® for identification with user-

defined or purchased Raman spectral libraries

www.bwtek.com 25

CH stretching


Improved Signal to Noise with i-Raman® Plus


i-Raman® Pro • Fully integrated portable fiber-optic probe Raman

spectrometer operable by embedded touchscreen software

• Spectral range from 65-3350 cm-1 covering low frequency modes with 785 nm excitation

• Deep cooling ( -25°C) and high dynamic range provides excellent S/N and performance for long integration times and capability to measure weak Raman signals

• Compact mobile design with integrated tablet PC operating touch-friendly BWSpec® Mobile software with real-time quantitative analysis capabilities

• Battery operation and external computer and BWSpec® also available


Readout Noise Comparison 0.1 second integration time

www.bwtek.com 29

i-Raman® Pro: Linear Mode, 0.1

sec

i-Raman® Plus: default, 0.1 sec


BWSpec® Mobile • Touch-friendly operation using embedded tablet computer • Real-time prediction and results control charts • Adjustable power down to 1% • Peak-picking; view microscope image • Database storage of data; ability to export spectra in several data formats


i-Raman® EX Technical Specifications


i-Raman® EX Material fluorescence reduces Raman

applicability on a small subset of materials – especially those that are highly colored, and many natural products including foodstuffs and nutraceuticals Utilize 1064 nm excitation Reduce fluorescence Increase productivity vs. other techniques

Research grade instrument provides enhanced material characterization opportunities

www.bwtek.com 33


i-Raman EX 1064 nm spectrometer – see materials better with lower fluorescence

• Raman spectra of extra virgin olive oil and sesame oil have lower fluorescence when measured with i-Raman EX


RAMAN ACCESSORIES


Sampling • Fiber optic probes can be easily

adapted to a variety of different sampling configurations

– Liquid flow cells – Gas flow cells – Optical microscopes – Probe holder – Cuvette or vial holder – Tripod for use with video

microscope


Fiber Optic Probe • Standoff or direct contact with sample • Lab grade and industrial probes for measurement

in diverse environments • Needle probes

• Fiber optic probes can be customized for

laboratory and industrial environment – Shaft length and material – Working distance – Window material – Fiber length

www.bwtek.com 37

Lab grade probe – standard

BAC 101 Industrial grade probe


Portable Video Microscope Sampling System (BAC151B)

• Compatible with all B&W Tek Raman probes • Precise target and focusing for precise

measurement of small sample volume • Digital camera and LED illuminator • Coarse and fine XYZ adjustment • Standard objectives from 10x to 100x • Bright and dark field illumination for various

sample surfaces • Portable with small footprint


B&W Tek Raman Probe Holder (BAC150B)

• Compatible with B&W Tek Raman probes

• Coarse and fine XYZ adjustment • Z-axis adjustment allows for laser

focusing on the desired plane


B&W Tek Enhanced Raman Cuvette Holder (BCR100A)

• Precise focusing • Three-point locking mechanism • Increase Raman signal up to 3 times in

comparison to a standard cuvette holder

• Standard 10x10 mm (inside dimension) cuvette

• Liquid or powder sample

www.bwtek.com 40

0

10000

20000

30000

40000

50000

60000

800 820 840 860 880 900

Wavelength (nm)

Rel

ativ

e In

ten

sity

Non-enhancedEnhanced


B&W Tek Liquid Sample Flow Cell

• Compatible with B&W Tek Raman probes • On-line process monitoring • Kalrez® O-ring, chemical resistant • Offers high throughput and stability • Quartz or sapphire window options


IQ/OQ available for i-Raman® series

• OQ includes the performance qualification on installation

• BWID® and BWSpec® software include system performance tests

• Successfully executed at global pharmaceutical companies

• Annual on-site PM protocols available


B&W TEK RAMAN SOFTWARE


B&W Tek Software

www.bwtek.com 45

BWSpec® : General spectroscopic software for instrument control, data collection and manipulation

BWID®: Qualitative analysis with spectral libraries

BWID®Pharma developed for use in regulated environment

BWIQ ®: Chemometric software for quantitative and qualitative analysis; includes real-time prediction functions

GemID™ : Integrated collection and ID software with Raman spectral library and images of > 350 gemstones


Spectral Analysis Examples

46

Correlation-based library searching for unknown material identification using HQI

PLS Regression Modeling for the development of concentration curve for quantitative prediction.

Method Development for verification of “known” materials using multivariate classification modeling to determine p-value. Measure 20

representative spectra Build method based on PCA and establish threshold p-

value (typically 0.05)

Test Method

500060007000800090001000011000Wavenumber cm-1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Abso

rban

ce U

nits • •

• •

PC1

PC2 • •

• •

PC1

PC2

Copyright 2016 B&W Tek www.bwtek.com

Compliant Software for i-Raman® Series

www.bwtek.com 47

• BWSP® and BWQT® are licensed software that are 21 CFR part 11 softwares for spectral data acquisition and for quantitative analysis

• This is private labeled software for use in regulated environments, and gives functionality for real-time analysis

• BWSP®: data acquisition and real-time monitoring with trend plots or quantitative

models from BWQT

• BWQT®: Quantitative model-building software; models can be used in real-time

with BWSP ® to give concentration values over time


BWID® Pharma Software

• 21 CFR Part 11 compliant software with electronic records and signatures • Operator/Developer/Administrator users • Protected User-defined, B&W Tek, and commercial third-party libraries

can be used • One click Identification or Verification of sample spectra • Reporting functions for analysis and instrument diagnostics


BWID® - PHARMA User Levels Operator:

• Run sample identification • Perform diagnostic tests • Print results for recently performed ID analysis and

performance test • Electronically sign an ID analysis record • Change his/her own password

Developer: • Create/modify a data library • Setup an operation preset method • Configure performance test parameters • Configure ID analysis report • Select, view, and print a report for any ID analysis and

performance test • Electronically sign and approve an ID analysis record • Configure graphical user interface (GUI) settings • Configure licensed instruments

Administrator: • Manage user accounts:

– View user accounts – Add/lock/unlock/reset/disa

ble a user account – Modify user account

properties – Backup/restore user

accounts file – Configure access policy


Spectrum Search: Identification • Get results immediately

following scan or on stored data

• MATCH/NO MATCH results

• Ability to add new spectrum to library after search


Spectrum Search: Verification

• Results immediately when run sample or on stored data

• To verify must choose product name

• PASS/FAIL results • Ability to add new

spectrum to library after search


Portable Raman Libraries work with BWID® • PTL-CHM

– Raman Chemicals library for portable Raman, with 1149 spectra of Common Chemicals, Narcotics, Explosives, Solvents and Plastics, supported in BWID 2.02 or higher version

• PTL-MNL – FDM Raman Minerals 785 SR (1085 Spectra). These spectra are part of a family

of mineral Raman libraries that have been collected and identified under the RRUFF project. The chemical names are presented with the RRUFF ID at the end. The minerals were characterized with a 785nm Laser and are supported in BWID 2.02 or higher version

Copyright 2016 B&W Tek 52

www.bwtek.com

Portable Raman Libraries available with BWID® • Raman Spectral Database - Complete Collection of 14202 Spectra • 25 separate libraries available including:

– Polymers and Polymer Additives – Food Additives and Food Packaging – Organometallics & Silicon – Biochemicals – Aldehydes and Ketones – Flavors, Fragrances and Cosmetic Ingredients – Pesticides – Semiconductor Chemicals – Hazardous Chemicals – Pharmaceuticals, Drugs and Antibiotics – Coatings – Paints –


53 www.bwtek.com

BWID® Audit Trail


Instrument Diagnostics • Performance test interface and tracking of results • Performance tests include:

– Test of USB instrument connection and noise test – Peak position using standard – Signal intensity stability

• Stability test

55 Copyright 2016 B&W Tek www.bwtek.com

e-signature

• Signature for review, approval, rejection available based on user level

• e-signature added to printed report


BWSpec® • General purpose spectrometer software


BWSpec® Software Interface


BWIQ® : Chemometric Software • Supports import of BWSpec® and

other data formats • Exploratory data analysis • Classification and Regression

methods

• Preprocessing methods for spectral smoothing, baseline correction and normalization

• Intuitive variable selection based on spectra as well as correlative coefficient

• Real time prediction functions


Chemometric (Spectral) Analysis

• Correlation analysis for material identification and/or verification (Qualitative)

• Multivariate analysis and complex systems with large

data sets (Quantitative / Qualitative) – Uncover underlying trends in the data and detect

outliers, – Develop classification models with PCA or PLS-DA

approaches – Develop quantitative models to predict response in

unknown data sets – Allows for real time monitoring to give quantitative for

classification results

www.bwtek.com 60

The use of mathematical and statistical methods for analysis of chemical or spectral data


BWIQ®: DEG in glycerin • B&W Tek i-Raman® Plus, 785nm Laser • 16 samples with diethylene glycol (DEG) in glycerin • DEG concentration from 0 – 48.3% • Integration time 20 second, 300 mW laser power


GemIDTM Software • Integrated collection and ID software with library and images of > 350

gemstones • powered by GemExpert in collaboration with Prof Dr. H.A. Hänni, FGA, former

director of the SSEF Swiss Gemmological Institute


GemIDTM Software

63 www.bwtek.com Copyright 2016 B&W Tek

RAMAN APPLICATIONS


Portable Raman Applications • Product contamination (i.e. alcohol, DEG in glycerin) • Counterfeit drug identification • Forensic analysis • Carbon research: carbon nanotubes; graphene • QC: 100% incoming raw material identification • Art and Archaeology- paints, pigments, object authenticity • Biomedical Analysis • Process Analytical Technology (PAT) • Environmental analysis • Geology and Gemology

– Minerals and rocks analysis – Gemstone identification and examination


Raman Applications in a Pharmaceutical Plant

www.bwtek.com 66

J. Rantanen, “Process analytical applications of Raman spectroscopy” JPP 59, 171-177 (2007)


• Pharmaceutical manufacturing facilities are moving toward 100% inspection of incoming raw materials, to support cGMP and PIC/S guidelines.

• Raman is ideal because 85 - 90% of common pharmaceutical ingredients are Raman active. Additionally Raman can measure through common packaging materials such as glass and plastic.

• Handheld Raman spectrometers are commonly used to provide on the spot "Pass/Fail" decision to verify the identity of incoming raw materials.

Verification of Incoming Raw Materials


Raman Spectra of Base and Salt forms of API

• The Raman spectra of the HCl salt of 4-methoxyphencyclidnin can be readily distinguished from the base of the same API

• Handheld Raman can be used as a rapid identification test for such pairs of APIs


Polymorphs • Materials can exist in different

polymorphic forms: the crystal structure can vary for the same chemical entity.

• Polymorphism is important in pharmaceutical products because the efficacy of a drug can be impacted on the solubility of the different crystal forms.


• Different polymorphs may have different stabilities, and may be formed preferentially based on the crystallization process.

Polymorphs of TiO2 also well known

Copyright 2015 B&W Tek, Inc. www.bwtek.com 70

• TiO2·H2SO4·H2O → TiO2·H2SO4 →TiO2 (nanophase) → TiO2 (anatase) → TiO2 (rutile)

• Can develop quantitative analysis of the phase content when have a sample set with known concentrations of i.e. anatase

Counterfeit Drug Identification • According to the World Health Organization’s estimates, ~10-15% of the world’s drug

supply (and about 1% in the US) is counterfeit - at a value of about $200B in 2010

• Raman Spectroscopy is currently being use for not only identification of counterfeit drug products but also to analyze the quality and purity

www.bwtek.com 71

• For example the FDA is currently using portable Raman spectrometers for the identification of glycerin contaminated with DEG.


Applications in Forensic Analysis

• Nondestructive Narcotic Drug identification

• Explosives Identification: – Exact Chemical Compositions of Material (i.e. PETN, RDX) – Binding Agents Within Explosive Materials

• Identification and Analysis of Toxic Solvents

and Chemical and Bio-warfare Agents

• Trace Forensic Evidence Analysis: – Including fibers, fabrics, pigments, inks, paint chips,

etc.


Illicit Drug Analysis • Portable Raman spectrometers are commonly

used for the Identification of a frequently encountered illicit street drug.

• In the example to the right we are showing the spectrum of a confiscated white powder which was analyzed using correlation analysis against a spectral library of common illicit drugs and positively identified at cocaine with a HQI of 99.13.


Identification of Explosives • Portable Raman spectrometers are also well suited for the

identification of explosives and hazardous materials. • Portable and handheld Raman gives the ability to do get

actionable data with identification at the point of interception of samples

• On-board spectral libraries and intelligent decision-making software make Raman spectroscopy ideally-suited to help emergency responders better understand the source and nature of hazardous materials.

www.bwtek.com 74

Raman spectra for two nitroamine high explosives (HMX and RDX) in red and green respectively, and

trinitrophenylmethylnitroamine (tetryl) in blue. Raman spectrum of pure an explosive containing TNT (sample), indicating a positive MATCH and identification


Product Contamination – Methanol-Laced Spirits • Over the past several years an alarming trend has become evident

that there are serious issues with contaminated alcohol within the EU, and in particular Eastern Europe.

• Studies have shown that the maximum tolerable concentration of methanol in alcoholic beverages with about 40% alcohol is about 2% (v/v) by volume.

• In September of 2012 when the Czech Republic banned the sale of hard liquor after 20 people died from the consumption of methanol-laced spirits.

• After an exhaustive study of different screening tools the Czech Republic turned to the use of portable Raman spectroscopy as the screening tool of choice for the identification and quantification of methanol in contaminated spirits.


Quantitation of Methanol-Laced Coconut Rum • CH3 bending vibration at 1013 cm-1 increases with methanol concentration. A PLS regression

method can be developed to readily measure concentration of MeOH in alcoholic beverage by portable Raman spectroscopy


Applications in Art & Archaeology • Portable Raman spectroscopy is widely used for the

analysis of paintings, ceramics, statues (surface coatings), documents, and other artifacts.

• The flexibility of portable instrumentation with fiber optics in conjunction with the non-destructive & non-contact nature of Raman allows measurements to be taken on-site.

• Raman can measure inorganics as well as organics, providing valuable information about paints, dyes, pigments and building materials and their origin and age.

• Spectral range extending as low as 65 cm-1, important in distinguishing pigments and crystalline form


Lead oxide (Pb3O4)

Cinnabar (HgS)

www.bwtek.com 78

Portable Raman Microscopy of Ancient Pigments

Courtesy of M.J. Ayora Cañada y A. Dominguez Universidad de Jaén

Lead oxide (Pb3O4)

Cinnabar (HgS)

Portable Raman allows for filed measurements such as that of pigments on the ceiling of a cathedral in Spain and in caves.

The i-Raman® spectrometer is connected to a tripod-mounted video microscope for precision alignment.


Analysis of Metal Corrosion • Raman spectroscopy was used at the Guggenheim Museum in Bilbao Spain to analyze

environmental effects on the corrosion of seven steel sculptures from Richard Serra.

• The figures below show the presence of lepidocrocite, magnetite, and iron sulfate from Richard Serra’s Inverse Blind Point sculpture, as well as a SEM image of the surface confirming the results of the Raman analysis

K. Castro et al., COST Action D42 Extended Abstract. 2011, 113–116


Applications in Geology and Mineralogy

• Portable Raman spectrometers are ideal for the identification of gemstones and minerals, including polymorphs and isomorphs.

• Non-contact, non-destructive sampling allows for analysis of precious or scarce samples, unlike other techniques such as LIBS.

• Anti-counterfeiting of precious, such as identification of diamond from zircon


Raman Evaluated for Geological Survey on Mars Before testing for life on other planets, feasibility studies are done on barren areas of the Earth. i-Raman® spectrometers were evaluated for use in geological surveys of Mars rocks and ice structure in Svalbard, Norway and Rio Tinto in Spain, where conditions are analogous to Mars

www.bwtek.com 81 Images Courtesy of Prof. Rull University of Valladolid and Pablo Sobron, SETI Institute


Analysis of Garnet Gemstones • Garnets are a class of silicate minerals which include a number of varieties with the general

form X3Y2(SiO4)3.

• Raman spectroscopy’s high selectivity allows for the differentiation of the different garnet varieties. Andradite and grossular fall into the ugrandite group of garnets (calcium in X site), while spessartine falls into the pyralspite group (aluminum in Y site).


Diamond or Zircon?

• Raman spectra of diamond and zircon are distinctly different

• Diamond shows only one very strong and sharp Raman band at around 1328 cm-1, which corresponds to the C-C stretching mode.

• Zircon shows multiple Raman bands at around 349, 431, 967 and 1002 cm-1, which correspond to the Si-O bending mode and stretching mode.


Raman for Process Monitoring (PAT) • Raman spectroscopy used for rapid off-line, at-line, on-line or in-line analysis

has the benefit of : – Fast (real-time or near real-time) – Nondestructive, timely, no external sampling – Provides the pulse of a process

www.bwtek.com 84

• PAT with Raman is used in the pharmaceutical, petrochemical, chemical and food industries for controlling:

– Chemical reactions – Crystallization processes – Blending operations – Coating – Polymorphic transitions

• Example for Raman as PAT : – Epoxy curing reaction monitoring – Monitoring liquid phase polymorphic transition

of citric acid.

Thermally induced polymorphic form transition


Citric Acid polymorphs • Citric acid monohydrate is formed

by crystallizing in cold water • Anhydrous citric acid crystallizes

from water at 34 deg C and higher • Conversion of the monohydrate to

the anhydrous form is achieved by heating and can readily be monitored in situ by Raman

• Trend plot shows the transition by disappearance of monohydrate peak at 1108 cm-1 and formation of anhydrous form with new peak at 1146cm-1


Detail View of Spectral Changes

OH stretching region


Raman real-time monitoring of cure of two-component epoxy system

• Tra-bond 2116 epoxy curing followed with 785 nm MiniRam® portable Raman spectrometer

www.bwtek.com 87

1275 cm-1 epoxide ring band decreases

on cure

Hardener consumed on reaction; peak at 2580 cm-1

disappears


in situ monitoring of low levels of acetone in ternary mixture

• Raman can be used to quantitatively measure acetone in the range from 0.1 to 1% in a multi-component solvent mixture

• i-Raman® Plus 785S with immersion probe used for real-time monitoring

• BWSpec® with timeline used for data acquisition, and BWIQ® for chemometric modeling

• Mixture of 95% THF/2.5%EtOH/2.5%MeOH was monitored as acetone was added in 0.1% increments- from 0.1 to 0.6% (0 to 1% in Run 1)

www.bwtek.com 88

BWS465-785S acetone : Dark_Subtracted

500 1000 1500 2000 2500 3000Raman Shift (cm-1)

0

10000

20000

30000

40000

50000

60000

Rela

tive Inte

nsity

acetone ethanol methanol Tetrahydrofuran

Acetone peaks 786 cm-1 and 1709 cm-1


Reference Spectra of Solvents

PLS to Quantitative Acetone in Solvent Mixture: 0- 0.6% Acetone

Copyright 2014 B&W Tek, Inc. www.bwtek.com 89

BWS465-785S acetone06_1 : Dark_Subtracted

500 1000 1500 2000 2500 3000Raman Shift (cm-1)

0

10000

20000

30000

40000

50000

Rel

ativ

e In

tens

ity

acetone00_1 acetone01_1 acetone02_1 acetone03_1 acetone04_1 acetone05_1 acetone06_1

2 factor PLS model RMSEP = 0.008

Predicted Results for Acetone Concentration


Polymer Reaction Monitoring with Raman

www.bwtek.com 91

• Raman spectroscopy is commonly used to monitor polymerization reactions such as styrene to polystyrene.

• This is typically done by normalizing the spectrum with respect to the aromatic ring band at ~1000 cm-1, and monitoring the decrease in intensity of the C=C bands around 1625 cm-1 as the C=C bonds are converted C-C bonds in the polymerization process .

styrene

polystyrene

(CC) Aromatic Ring

C=C

Data Courtesy of Dr. Henryk Herman of Gnosys Global


Contamination of Extra Virgin Olive Oils • To improve profit margins there are many

instances of the adulteration of extra virgin olive oil (EVOO) with light olive oil or other cheaper ingredients

• A feasibility study was performed with 8 samples spiked with 0.21- 19.15% and measured on the i-Raman® EX

• BWIQ® software used to develop a quantitative model for the concentration of light oil in EVOO

www.bwtek.com 92

2 factor PLS model Error ~ 1.6%


Raman Analysis of Carbon Nanotubes (CNT) • RBM – Radial breathing modes,

which probe the lattice structure of the CNT allowing for the calculation of tube diameter.

• D Band – Disorder band, measures the degree of amorphism of the CNT.

• G Band – Tangential Mode, measures the degree of crystallinity (diamond like

structure) of the CNT.


Applications in the Biomedical Diagnostics • Raman spectroscopy is becoming more pervasive in

biomedical diagnostics because of the demand for near real time and minimally invasive analysis.

• Applications include: – Biopsies for analysis of tissue sample

abnormalities – Cytology investigations at the cellular level – Drug efficacy studies – Identification of biomarkers for early stage

disease detection i.e. cancer, tuberculosis – Surgical targets and treatment monitoring.

• Surface Enhanced Raman (SERS) provides signal enhancement of up to 106 and can aid in trace level detection

• SERS used with Raman labels captured on SERS substrate and used to capture antigens specific to different diseases

www.bwtek.com 94 Copyright 2016 B&W Tek “Diagnosing Cancer with Raman Spectroscopy”, R. Thomas, K. Bakeev, M. Claybourn & R. Chimenti , Spectroscopy, 28(9), 36, 2013.

Assessment of Axillary Lymph Nodes in Breast Cancer with Raman Spectroscopy

www.bwtek.com 95

Images Courtesy of Jonathan Horsnell,

Gloucester Royal Hospital Department of Biophotonics

• Studies by researchers in the UK have shown that Raman spectroscopy can detect differences in tissue composition, and in particular a wide range of cancer pathologies.

• Using PCA-LDA data processing to evaluate the Raman spectra of lymph nodes they have confirmed that the technique can match the sensitivities and specificities of current histopathological techniques.


Applications in Polymer Science

www.bwtek.com 96

• Portable Raman spectroscopy helps to meet needs of the polymer, additive, compounding and master-batch industries, by allowing for an audit trail to certify the link between the quality of raw materials and finished product.

• Raman has many applications in both QA and QC including incoming material inspections, measurement of polymer grade, blend ratios, additives, and ageing.

• It can aid in the ooptimization of formulations for desired properties and performance by predicting:

• Processing properties – MFI, liquid viscosity

• Thermal properties – glass transition, melting point

• Physical properties – density, mechanical modulus and strength, impact strength

• Fire properties – UL scores, LOI, flame retardants


Amorphous/Crystalline Content

• Crystalline materials have more ordered structure, and therefore sharper bands in the Raman spectrum

• Degree of crystallinity can be quantified rapidly using Raman

www.bwtek.com 97

BWS465-785H-BAS Amorphous sample : Dark_Subtracted

700 800 900 1000 1100 1200Raman Shift (cm-1)

0

10000

20000

30000

Rel

ativ

e In

tens

ity

30% CrystallinityAmorphous sample


Polymer Identification


Environmental Science • Water pollution detection using SERS technology • Identification of contaminants in water • Petrochemical analysis • Identification and analysis of sediments in water


Inspection of Plastic Toys for Phthalates • Phthalates have been identified as harmful to

reproductive organs when ingested by humans • Their presence in plastic toys as a softener of

PVC is alarming in such toys as the phthalates may leach to the surface, and be dissolved in liquids thus passing on to children

• Raman peaks for phthalate at 1040 cm-1 and 1729 cm-1 are identified in the spectra of toys from different manufacturers


0 500 1000 1500 2000 2500 3000

0

10000

20000

30000

40000

50000

60000

Relat

ive in

tens

ity (a

.u.)

Raman shift (cm-1)

Toys from promotional give-away

Toy from Fisher-Price

Phthalate band seen in 2 items from give-away

Quantitating Phthalate Levels • The Raman spectra of six samples with different DEHP (Bis(2-

ethylhexyl)phthalate) concentrations ranging from 0% to 30% were used for analysis of phthalate content.

• A linear calibration curve of the 1729cm-1 Raman peak vs. DEHP concentration indicates that the i-Raman® Plus Raman system is able to measure DEHP concentration as low as 0.5% or better.


Some Handheld Raman Applications


Counterfeit Detection: Antimalarials • Raman spectra of the active ingredients

of antimalarial Coartem: lumafantrine and artemethur measured on the handheld NanoRam

• Raman spectra collected with the NanoRam of an authentic antimalarial tablet and counterfeit show that the counterfeit does not contain the Raman signature of either of the APIs

• The counterfeit gives FAIL result when using the method for the authentic antimalarial

Copyright 2016 B&W Tek www.bwtek.com 103

Handheld Raman Applications • The utility of handheld Raman crosses many application

areas as it can serve as an answer box for identification of unknowns

• Adoption of handheld Raman as a screening tool for security, safety, customs for detection of dangerous and illicit substances continues to grow

• Identification of minerals, gemstones & plastics • Environmental monitoring and food safety • Applications in archaeology and art for field work include

study of degradation of Valence aqueducts in Istanbul from air pollution


O. Unsalan & A.H. Kuzucuoglu, Spectrochimica Acta Part A: Mol. And Biomol. Spectro 152 (2016) 572–576

Low levels of narcotics in drinking water • As low as 1 ppm amphetamine in water detected using NanoRam and

sampling with plastic-based SERS substrate: FlexiBrite


Z. Xu, J. Jiang, X. Wang, K. Han, A. Ameen, I. Khan, T. Chang and G. L. Liu, 2016 Nanoscale; DOI: 10.1039/c5nr08357e

Raman has proven to be a promising tool to increase operational capabilities and reduce cost while

providing solutions from rapid material identification to process understanding and real-

time analysis.

Summary


Thank you for your attention

www.bwtek.com 107

B&W Tek, Inc. 302-368-7824

www.bwtek.com www.bwtek.com/support

420000002-A07 DRAFT (05/18/2016)


http://www.bwtek.com/

i-Raman® Series System Setup


Relative Intensity Correction

• In Raman spectroscopy, intensity correction is applied to correct relative intensities against a traceable standard for individual spectrometers

• For systems with 785 nm excitation use SRM2241

• Enable the correction in the software using a factory-generated correction file (Ratio3 file)


Permanent Wavelength Calibration

• NIST traceable wavelength calibration ensuring Raman shift accuracy with standards- Tylenol and cyclohexane

• Follows ASTM E1840-96(2007)

www.bwtek.com 110 Copyright 2016 B&W Tek 420000002-B (2016/05/25)

overview of raman spectroscopy and b&w tek portable ... · •positioning of portable raman vs...

Documents