Does Nitrate Need Colorimetry to Read With Uv Vis

UV-Visible spectroscopy

International schoolhouse of photonics, Cochin academy of science and engineering, Cochin, Kerala, 682022

Guided by:

Dr. Parag sharma

Senior scientist, Physico Mechanical Metrology Division, CSIR-National Physical Laboratory(NPL), New Delhi, 110012

Abstract

Spectroscopy is the study of interaction of electromagnetic radiation with matter based on the Bohr-Einstein frequency human relationship $Eastward=hv$ . Excitation of electrons is due to the absorption of low-cal in the ultraviolet and visible regions and this will just happen if the free energy of incident lite is exactly the energy required for the excitation. Basic principle of spectroscopy is the Beer-Lambert'due south law, which states that absorption of incident radiations is directly proportional to the concentration and the thickness of the textile. In UV-VIS Spectroscopy, a continuum range of wavelengths from 200nm to 1100nm is used. The visible region is obtained by a halogen lamp. The spectral energy of halogen lamp rapidly decreases below 400nm. Therefore a gas discharge lamp is used in ultraviolet region, for which hydrogen or deuterium lamp are the best. I have operated the automatic UV-VIS Spectrometer (PerkinElmer Lambda 35), a double axle spectrometer for samples (dyes) rhodamine, thymol bluish, phenol red and methylene blueish. Now I am practicing visible spectroscopy past aligning a manual setup using an LED source, monochromator and a detector for same samples. Here the LED source, which has a spectral range of 420nm to 720nm is directed towards monochromator. The monochromator (Digikrom) has an entrance slit, collimating mirrors, diffraction grating, focusing mirror and an exit slit. The lite entering through the slit is collimated and directed to the diffraction grating which is tilted to select the desired wavelength. The diffracted lite is focused via a focusing mirror. Afterwards information technology is passed through the go out slit towards the photo-detector. Photo detector is a device which counts the intensity of the transmitted radiation instantaneously. It consists of a simple p-n junction which can exist made by defusing a p-type impurity into an n-blazon bulk silicon wafer or vice verse. The defused surface area is called active photodiode area which is coated past an anti reflecting thin film for maximum detection. Later I volition exist doing the grooming of the organic dyes and their uv-visible spectroscopic analysis.

Keywords: Ultraviolet-Visible-near Infrared (UV-VIS-NIR), Ultraviolet-Visible (UV-VIS) , Light emitting diode (LED).

INTRODUCTION

Spectroscopy is the branch of science which deals with interaction of electromagnetic radiations with materials. In other words information technology is an analytical method for qualitative and quantitative analysis by use of lite. This technique begins from Issac Newton's experiment (1666-1672), which he defined the term 'spectrum' to describe the consecutive colours derived from the dispersion of white light through a prism. After it was explained as whatever interaction of electomagnetic waves with matter. In early 19^thcentury, Joseph von Fraunhofer made experimental advances with dispersive spectrometers that enabled spectroscopy to become a more precise, quantitative and scientific technique. The Bouguer-Lambert Beer law in 1852 fabricated the basis for the quantitative evaluation of assimilation measurements in the early period. This led firstly to colorimetry, then to photometry and finally to spectrophotometry. This evolution was along with the development of detectors for measuring light intensities, i.e. silicon photograph-diode detector, which allow simultaneous measurement of the complete spectrum.

Recently, the definition has been expanded to include the report of the interactions between particles such equally electrons, protons, and ions, as well as their interaction with other particles every bit a function of their collision energy. Spectroscopy is widely used equally an exploratory tool in the fields of physics, chemistry, and astronomy, for decision of composition, physical structure and electronic construction of matter at atomic calibration, molecular scale, macro scale, and over astronomical distances. Spectroscopic assay has a key part in the development of the most fundamental theories in physics, including quantum mechanics, the special and full general theories of relativity, and quantum electrodynamics. Spectroscopy has made a key office in evolution of scientific understanding.

Spectroscopy accept became an invaluable aid towards structural identification in mod organic chemistry. Consequently, every pupil of science should be aware of the range of information bachelor from spectroscopic techniques, and be given a practical introduction to the basic spectroscopic methods from the beginning of his training itself. Isolated experiments in spectroscopy have also been described for the beginner. With the development of quantum chemistry, increasing attention was paid to the correlation betwixt light absorption and the structure of affair with the result that in recent decades a number of excellent discussions of the theory of electronic spectroscopy have been published.

Spectroscopic techniques have been practical virtually in all technical fields of science and technology. Radio-frequency spectroscopy of nuclei in a magnetic field has been employed in a medical technique chosen magnetic resonance imaging (MRI) to visualize the internal soft tissue of the torso with unprecedented resolution. Microwave spectroscopy was under to find the and then-called three-degree blackbody radiation, the remnant of the big bang. The internal structure of the proton and neutron and the country of the early universe upwardly to the first thousandth of a second of its existence are existence unravelled with spectroscopic techniques using loftier-energy particle accelerators. The constituents of distant stars, intergalactic molecules, and fifty-fifty the primordial abundance of the elements before the formation of the kickoff stars can be determined by optical, radio, and 10-ray spectroscopy.

In this affiliate, we talk most uv-visible spectroscopy. ­In which the spectroscopy is done corresponding to wavelengths varying from 200nm to 1100nm with material.

SPECTROSCOPY

Spectroscopy is the written report of interaction of electromagnetic radiations with matter based on the Bohr-Einstein frequency human relationship $E=hv$ , hither h is the proportionality constant chosen Planck'southward constant (6.626 x 10-34 J southward) and v is frequancy. This relationship relates the discrete atomic or molecular free energy with the frequency. When an Electromagnetic radiations is incident on a matter, phenomena similar reflection, manual, absorption, etc. are occurring. The measurement of intensity as a function of wavelength or frequency is defined equally a spectrum. When the energy of incident photon is sufficient to excite the electron in the affair, the electron absorbs free energy and get excited from ground country to a higher free energy land.

Measurement of radiation intensity equally a function of wavelength is described by spectroscopy. Spectrometers, spectrophotometers, spectrographs or spectral analyzers are referred to as spectral measurement devices. Spectroscopic techniques are extremely sensitive. Single atoms and even dissimilar isotopes of the same atom tin can be detected among ten^twenty or more atoms of a different species. Trace amounts of pollutants or contaminants are often detected most effectively by spectroscopic techniques. Certain types of microwave, optical, and gamma-ray spectroscopy are capable of measuring infinitesimal frequency shifts in narrow spectroscopic lines. Frequency shifts of 1 role in x¹⁵ of the frequency can be observed with ultrahigh resolution laser techniques. Because of this sensitivity, the most accurate physical measurements take been frequency measurements. Spectroscopy now covers a sizable fraction of the electromagnetic spectrum. Spectroscopic techniques are non confined to electromagnetic radiation, however. Because the free energy E of a photon is related to its frequency ν by the relation $Due east=hv$ , spectroscopy is actually the measure of the interaction of photons with matter as a part of the photon free energy. In instances where the probe particle is not a photon, spectroscopy refers to the measurement of how the particle interacts with the test particle or material equally a function of the energy of the probe particle.

SPECTRUM

The measurement of radiation intensity against wavelength is divers equally a spectrum. Spectrum can be differentiated equally absorption and emission spectrum. In which an absorption spectrum gives the information almost the measure of absorbance against wavelengths whereas, emission spectrum gives mensurate of emission due to photo-brilliance. Absorption spectrum is derived or calculated from the transmission spectrum which we are actually measuring. While emission spectrum itself is a transmission spectrum. Each of these spectrums explains the characteristics of that sample. Uv –visible spectroscopy consists of an absorption spectrum. An absorption spectrum gives information about the molar assimilation coefficient, concentration of the sample, optical band gap etc.Example for spectra of a developed standard LED (red line) and a typical white LED (blue dotted line) is given beneath.

PRINCIPLE AND SETUP

Basic principle of spectroscopy is the Beer-Lambert'due south law (besides known as beer'south law) that  relates the attenuation of light to the backdrop of the fabric through which the light is travelling. The law was discovered by Pierre Bouguer earlier 1729. It is often attributed to Johann Heinrich Lambert, who cited Bouguer'sEssai d'optique sur la gradation de la lumière (Claude Jombert, Paris, 1729) and fifty-fifty quoted from information technology in hisPhotometria in 1760. Lambert'due south constabulary stated that absorbance of a material is straight proportional to its thickness (path length). Much later, August Beer discovered some other attenuation relation in 1852. Beer'south law stated that absorbance is proportional to the concentrations of the material sample. The modern derivation of the Beer–Lambert police combines the two laws and correlates the absorbance to both the concentrations and the thickness of the material. Absorption spectra of chemical samples are generated when a beam of electromagnetic radiations is passed through a sample, and the chemical sample absorbs a portion of the photons of electromagnetic energy passing through the sample.

Spectroscopy can be done for a material by having a calorie-free source, a monochromator and a photo detector, which counts the number of photons. The light source is illuminated and passed through a monochromator which separates the white lite into its consecutive colours, and is passed through the material. Intensity is measured against each wavelength. Every bit the light source is passed through the setup, measurements are recorded for incident and transmitted radiations. These measurements are used to calculate the transmission and assimilation spectra of the fabric. While many modernistic instruments perform Beer's law calculations by simply comparison a test sample with a reference sample which accept a negligible absorbance. The graphing method assumes a directly-line relationship between absorbance and concentration, which is valid only for dilute solutions.

Transmittance, T = I/I₀ Absorbance, A = two-log(%T)

I –Transmitted radiation intensity I₀ – Incident radiation intensity

When the light beams are passed through a dilute sample, the absorption will be less since there is simply less number of arresting particles presented. The calorie-free axle was passed through a full-bodied sample. The intensity of the transmitted beam was considerably depression, which leads to violation of Beer Lambert'south law.

The police thus states that for a dilute solution, A = Kcl

Where,

• A – absorbance
• K – tooth absorbance coefficient
• c– molar concentration
• l - Path length

UV-VISIBLE SPECTROSCOPY

Ultraviolet -Visible Spectroscopy is i of the oldest and nearly widely used method in molecular spectroscopy. Within the whole electromagnetic spectrum, but ultraviolet and visible range which occupies just a very narrow frequencyregion corresponds to the detached diminutive or molecular energy levels. So chosen 'electronic spectroscopy'. Excitation of electrons in both atoms and molecules are due to the absorption of light in the ultraviolet and visible range. Since the energy levels of matter are quantized, excitation volition only happen if the energy of incident low-cal is exactly the energy required of the excitation. Larger energy gap between the energy levels requires wavelengths of higher energy, resulting in absorption of shorter wavelength lite. On every possible excitation, electrons are excited from a depression energy ground state which is a completely filled orbital to a college energy excited state empty anti-binding orbital (Fig. iii).

Energy corresponding to possible electronic transitions.

All molecules will undergo electronic excitation on following assimilation of light. Absorption of light in the uv-visible range will only result in the following transitions(Fig. 4).

Electronic excitation in the uv-visible range

Therefore in gild to absorb light in the region from 200 - 800 nm (where spectra are measured), the molecule must contain either a sigma bonds or atoms with non-bonding orbitals. There are some limits at either the side of electromagnetic spectrum, which are not stock-still. Shorter wavelengths are restricted to measure by apparatus or it is not easier with our instruments. Longer wavelength doesn't makes any sense when passed through a material since it exhibits considerably less energy. So virtually of the compounds exhibit no traceable absorption by the electronic excitation in this region.

Range of electro-magnetic spectrum and their limits

Major applications of uv-vis spectroscopy are:

• Quantitative and Qualitative analysis.
• Determination of molecular weight.
• Determination of molar absorbance coefficient.
• Decision of unknown compound.
• Detection of functional group.
• Detection of isomers and geometrical isomers.
• Detection of impurities.

Major advantages of uv-vis spectroscopy are:

• High sensitivity.
• Require only modest book of sample.
• Linearity over broad range of concentration.
• Can be used with gradient elution.

Major disadvantages of uv-vis spectroscopy are:

• Not linear for high concentration.
• Does not work with compounds that do not absorb low-cal at this wavelength region.
• Requirement of loftier voltage for initiation.
• Generates significant rut and requires external cooling.

In this chapter, uv-visible spectroscopy of the post-obit dyes which were initially prepared at a concentration of 1 milli molar and afterward diluted to 25 micro tooth are performing(Fig. six):

• Rhodamine
• Thymol blue.
• Phenol red.
• Methylene bluish.

Dyes prepared for spectroscopy

INSTRUMENTATION

SOURCE

In UV-VIS Spectroscopy, a continuum range of wavelengths from 200nm to 1100nm are used.The visible region is obtained by a halogen lamb likewise know as tungsten halogen, quartz-element of group vii or quartz iodine. It is an incandescent lamp and it consists of a compactly sealed tungsten filament in a transparent glass. Information technology is a black-body source whose spectral energy distribution is described past Planck's radiation formula. As the wavelength of emitted radiation moves to shorter region, temperature goes very loftier which in turns evaporates the tungsten coil, which results in a shorter lamp life. The evaporated tungsten ringlet condenses on the drinking glass which reduces the spectral energy. In the modern century, the sealed glass is also filled with a mixture of inert gas and a pocket-size amount of halogen. This creates a element of group vii cycle that the evaporated tungsten decomposes back on the tungsten coil, the evaporation is reduced fifty-fifty in prolonged use resulting a higher spectral energy in the visible region. Thus keeping a longer life and maintaining a clear drinking glass. Still, the bulb should go on a temperature greater than 250 degree Celsius to keep the element of group vii bicycle active.

The spectral energy of element of group vii lamp rapidly decreases below 400nm. Therefore a gas discharge lamp is used in ultraviolet region, for which hydrogen or deuterium lamp are the best. Generally we use deuterium lamp which is a low force per unit area gas-discharge light source in a spectroscopy. Basically a deuterium lamp uses a tungsten filament and anode is placed on contrary sides of a nickel box structure designed for the all-time output. Yet, the filament doesn't produce the light. Instead of that, an arc is created in between the filament and anode. This setup is to heat the filament and is turned off after the discharge begins.

Various UV radiation sources are:

• Deuteriun lamp.
• Hydrogen lamp.
• Tungsten lamp.
• Xenon belch lamp.
• Mercury arc lamp.

Various Visibe radiation sources are:

• Tungsten lamp.
• Mercury vapour lamp.
• Carbonone lamp.

MONOCHROMATOR

The purpose of a monochromator is to produce a unmarried spectral line from a broadband (multi-wavelength) source. In spectrometers, this can be used to collect lite from an atomic emission source, like the atomic emission detector, and permit merely a specific line to go out. Information technology can as well be used to isolate a single line from a light source such equally a hollow cathode lamp. The simple monochromator shown here is called a Czerny-Turner monochromator.

The elements in the monochromator are:

• Entrance slit.
• Collimating mirror.
• Diffraction grating.
• Focusing mirror.
• Go out slit.

Schematic represnetation of Czerny-Turner monochromator.

This is the basic expression governing diffraction gratings is mλ=d (sin i + sinθ)

Where, 'd' is the groove spacing, 'i' is the bending of incidence, 'θ'is the diffraction angle, 'λ' is the wavelength, and thou is the order. This means that when d, m, and i are fixed, light of wavelength λ is diffracted in direction θ. The expression indicates the presence of higher-order light. If d, i, and λ are fixed, a different value of m results in a different value of θ. This indicates that low-cal of wavelength λ diffracts in multiple angles θ, as shown in figure below. These low-cal directions are named using a combination of the m value and the + or - sign, such equally +1st-club calorie-free or -1st-gild low-cal. Incidentally, the lite when m=0 is known equally zip-order light, for which the diffraction angle θ is equal to the angle of incidence i. This is reflected equally white light, equivalent to normal specular reflection. The various lite orders of a diffraction grating event in dispersion of the energy and a reduction in low-cal utilization efficiency. However, the diffracted light energy from a diffraction grating with a fine sawtooth profile is concentrated in the direction of the specular reflection, as shown in Figure. This wavelength is known equally the "blaze wavelength." The diffraction grating in spectrophotometer is normally used near the bonfire wavelength.

Saw molar structure of grating showing dissimilar orders of diffracted calorie-free beams.

Photo DETECTOR

A photo detector is a semiconductor device which converts low-cal energy to electric energy. It consists of a simple P-N junction diode and is designed to work in reverse biased condition. The photons budgeted the diode are absorbed by the photodiode and current is generated. Information technology can be made past defusing a p-blazon impurity into a n-type bulk silicon wafer or vice verse. The defused expanse is called active photodiode area which is coated past an anti reflecting thin pic for maximum detection and is covered by an illumination window. Non agile surface area is deposited by thick layer of silicon oxide. Some photodiodes are manufactured with born filters and lenses having different surface areas. Response time of the photodiode is inversely proportional to the expanse. Solar prison cell is one of the best examples for photodiode. To increase the speed of response, a PIN junction is used instead of P-North junction.

Photograph detectors may be classified past their machinery for detection:

• PN Photodiode.
• Schottky Photo Diode.
• PIN Photodiode.
• Avalanche Photodiode.

Unlike photo detectors are used in different configurations. Unmarried sensors are used to observe the overall light levels. For the detection of distributions along a line, a 1-D assortment of photo detectors are used similar to spectrophotometer and for image sensing, a two-D assortment of photo detectors are used. Photo detectors can be identified by analysing its characteristics such every bit:

• Spectral response.
• Responsivity.
• Dark electric current.
• Response time.
• Quantum efficiency.
• Gain .

When a photon of high energy hits the diode, an electron-pigsty pair is generated. This mechanism electron-pigsty pair creates the electric current proportional to the intensity of the incoming photon and this machinery is likewise called inner photoelectric effect.

Schematic representation of working of photograph-diode

SPECTROMETER

An optical spectrometer basically measures the intensity of the light as a part of wavelength or frequency. Optical spectrometers are of two kinds. They are double beam spectrometer and single beam spectrometer. A single beam spectrometer have only i sample holder, and mensurate only one transmitted light beam while a double beam spectrometer have two sample holders, one for the sample which is to be analyzed and i for the reference sample to remove the errors while measurement. Double beam spectrometer measures the intensity of ii transmitted light beams (sample and reference) simultaneously. Given below is a typical schematic representation of single and double beam spectrometers.

Schematic representation of double beams and single beam spectrometers.

Image of the manually aligned spectrometer is given below, which consists of an LED source, monochromator (Digikrom) with hand control keyboard, focussing lenses, cuvette, photo detector and multi-meter to note downward the intensity of transmitted light.

Image showing the monochromator with manus control and source of the manually aligned spectrometer.

Image evidence in the optics of manually aligned spectrometer.

RESULTS AND DISCUSSION

Absorption spectrum of the dyes (25 micro molar concentration) using manually aligned setup are given beneath:

Absorption spectrum of Rhodamine.

Absorption spectrum of Thymol blueish.

Absorption spectrum of Phenol scarlet.

Assimilation spectrum of Methylene bluish.

Assimilation spectrum of the dyes (25 micro molar concentration) using avant-garde spectrometer are given below:

Absorption spectrum of Rhodamine.

Absorption spectrum of Thymol blue.

Absorption spectrum of Phenol reddish.

 Percentage mistake in decision of wavelength of  maximum assimilation using manual setup compared to advanced spectrometer.

Extinction coefficient (concentration of 25 micro tooth).

Per centum error in determination of extinction coefficient max using manual setup compared to advanced spectrometer.

Band gap adamant using manually aligned spectrometer:

Optical band gap of Rhodamine.

Optical band gap of Thymol bue.

Optical ring gap of Phenol red.

Optical band gap of Methylene bluish.

Band gap determined using advanced spectrometer:

Optical band gap of Rhodamine.

Optical band gap of Thymol bluish.

Optical band gap of Phenol scarlet.

Optical band gap of Methylene bluish.

Percent error in determination of optical band gap using manual setup compared to avant-garde spectrometer.

From the above observations, it has been noticed that there occurs an mistake of 0.53 % to 5.52 % in measurement of wavelength of maximum absorbance, 2.77 % to 62.35 % of error in conclusion of molar absorption coefficient and upto 25% of fault in measurement of optical ring gap using the manually aligned setup.

SOURCES OF ERRORS

• Lack of accuracy in manual alignment of optics.
• Lack of accurateness in monochromator.
• Low intensity of light coming from the monochromator.
• Lack of accuracy in focusing and collimating the light beam.
• Lack of accurateness in dye preparation.
• Lack of accuracy in readings taken for the intensity of transmitted low-cal.
• Lack of accurateness in calculations and conversions.

Conclusion

In this affiliate, I have done a comparison of accurateness in measurement of absorption spectrum, wavelength of maximum absorption, molar absorption coefficient (extinction coefficient) and optical band gap using uv-visible spectroscopy done by manually aligned spectrometer with the advanced spectrometer to determine the possible percentage of errors and also the sources of these errors have been discussed.

REFERENCES

[1] Perkampus, H.H., 2013.UV-VIS Spectroscopy and its Applications.Springer Scientific discipline & Business Media.

[2] Gupta, Kumar and Sharma, Pragathi Prakashan Meerat-(1983)-Elements of Spectroscopy,6 thursday
edition

[3] Brown, J.Q., Vishwanath, K., Palmer, G.M. and Ramanujam, N., 2009. Advances in quantitative UV–visible spectroscopy for clinical and pre-clinical application in cancer.

[four]Giusti, Chiliad.M. and Wrolstad, R.Due east., 2001. Characterization and measurement of anthocyanins by UV‐visible spectroscopy.

[5] Platt, U. and Stutz, J., 2008. Differential absorption spectroscopy. InDifferential Optical Assimilation Spectroscopy(pp. 135-174). Springer, Berlin, Heidelberg.

[six] BV, D.C. and HYDRAULICS, D., 1962. Absorption spectroscopy.

[seven] Ajoy Ghatak, Tata Mc Grow Colina, (2009)-Textbook of Eyes.

[8] White, Tata Mc Graw Loma NY 1983-Diminutive spectra.

[ix] C. Scott, S. Chand Co, (1998)-Introduction to eyes and optical imaging

[10] C. 50. Arora, S. Chand publishing company, 2001-Atomic and molecular physics, 3rd edition.

[eleven] Straughen and Walker, Vol I John Wiley & Sons 1976-Spectroscopy.

[12] Beiser, Tata Mc Graw Loma 2003- Concepts of Modernistic Physics,.

[13] H. Due south. Mani and M. K. Mehta, Affilated East and West (1988)-Introduction to Modernistic Physics.

[xiv] R. S. Sirohi, Orient Longman, (1993)-Wave optics and applications.

[15] H. S. Mani and G. K. Mehta, Affilated Due east and Westward (1988)-Introduction to Modern Physics.

ACKNOWLEDGEMENTS

First of all, I am thankful to my guide, Dr. Parag Sharma, Senior scientist, Physico Mechanical Metrology Division, CSIR-National Physical Laboratory(NPL), New Delhi, who has guided me throughout the menses and made this project improve. His special attending and motivation towards me and my project were the important factors that made this projection done.

I would similar to thank Dr. Ranjana Mehrotra (main scientist), Mr. V.K. Jaiswal (senior scientist) and Dr. Shibu Saha (scientist) for the back up to make this project amend.

I would similar to give thanks Mr. Prince Sharma for co-guiding me. Beyond his works, he had spend a lot of valuable time for guiding and motivating me for the project and I am grateful for his every contribution. I am besides thankful to all the seniors in the section, specially, Bhumika Ray, Kaweri Gambhir, Rajeev Dwivedi, Vijeta, Swati Gangwar, Manjari Srivastava, Krishna Rathore, Narender Signh Bisht and Avina Reshel Dsouza.

I am too thankful to Indian Academy of scientific discipline for giving me a wonderful opportunity to have an feel in the one of the best laboratory available beyond the country.

And finally, I am thankful to my love parents, teachers and my friends who have supported me throughout the period with their valuable suggestions and guidance.

APPENDICES

Extinction coefficient also called Molar absorption coefficient, is a term which defines how much a chemical sample absorbs electromagnetic radiations at particular wavelength which is an intrincic belongings of the sample that is dependent on the chemical composition and structure of the sample. This coefficient relates the absorbance with the concentration of the sample and the path length of the light as A = Kcl, where "Chiliad" is the extinction coefficient.

Extinction coefficient can exist determined as follows,

K= A/cl .

Optical band gap of a sample is a range of energy for which there occurs no electronic transitions due due to the radiations of lower energy.

Optical band gap can be calculated by the following method,

• Plot the absorption spectrum.
• From the absorption spectrum, calculate extinction coefficient for each wavelength.
• Calculate the energy corresponding to each wavelength.
• Summate the square of the product of the energy and extinction coefficient respective to each wavelength.
• Plot the graph for energy 5/s foursquare of the product of the energy and extinction coefficient with energy on X-axis.
• Drwa a tangent for the obtained graph at the region of acme with constant positive slope and the X intercept is the optical ring gap in eV.

Notes

References

Hyperlink

Glossary

Source

• Fig 1a: https://medium.com/search?q=design

• Fig i: https://images.app.goo.gl/AjSf5xt39Nq3BsR26

• Fig 2: Introduction to uv-visible spectroscopy. RSC, advancing the chemical life

• Fig 3: Introduction to uv-visible spectroscopy. RSC, advancing the chemical life

• Fig 4: Perkampus, Heinz-Helmut.UV-VIS Spectroscopy and its Applications. Springer Science & Business Media, 2013.

• Fig v: Prepared in the lab

• Fig 6: https://images.app.goo.gl/E6jfUbx1oeACgAZD9

• Fig 7: https://images.app.goo.gl/pFkYUcsQK524F8Yt9

• Fig 8: https://images.app.goo.gl/HDxxfxJriY6YLrTE8

• Fig 9: https://images.app.goo.gl/oytfB6XMhsBpzZ1P7

• Fig 10: https://images.app.goo.gl/zf4hUFuq9oFgx8ZUA

• Fig 11: Prototype taken from lab.

• Fig 12: Paradigm taken from lab.

Does Nitrate Need Colorimetry to Read With Uv Vis

Source: http://reports.ias.ac.in/report/19397/uv-visible-spectroscopy

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