 Okay, so good morning to everybody. So for this discussion, we will be talking about the different analytical techniques, instrumentation, and automation for clinical chemistry. So for everybody who wants to follow along, you can actually open your book. This will be coming from Bishop Chapter 5, and then the succeeding topics that we're going to discuss will be coming from Chapter 6 and Chapter 7. We'll be talking about the different analytical techniques, instrumentation, and also automation that is being used in the clinical chemistry section. So always remember that in the clinical chemistry section, we're actually measuring different analytes in the laboratory. So whether that is a routine or a special analyte, we need special and we need analytical techniques and instrument for us to be able to identify and for us to be able to measure them properly inside the laboratory. So please do take note that the premise of our discussion for today will be covering, the first part will be covering your spectrophotometer. Spectrophotometer and then atomic absorption, spectrophotometry, fluorometry, chemiluminescence, and even your electrophoresis. So all of these 11 analytical techniques, we're going to discuss them one by one and hopefully you'll be able to understand them better as we move along to the different topics for clinical chemistry. So let's start off with your spectrophotometry or of course the instrument that we're using in here is your spectrophotometer. So let's move on. Now, so your spectrophotometry is actually a type of absorption spectroscopy. So what do we mean by absorption spectroscopy? So we're actually measuring the light being absorbed by a particular analyte. So take for example, you have a particular element, a particular biomolecule, be it a carbohydrate, a lipid, or even a protein. So they have a characteristic absorption. They do have their characteristic molar absorptivity. So they are capable of absorbing light coming from your light source. And when they absorb light, it enables us now. It provides us information as medical technologies, medical laboratory scientists. They provide us a means for us to be able to qualitatively and quantitatively measure this particular analyte in the body. So with the help of absorption spectroscopy, we can now quantify and we can now also identify your analyte qualitatively. When we say qualitatively, we're just checking the presence or the absence of a particular analyte. And then when we are talking about quantitative methods, these are now the time when we are getting its absolute or relative concentration so that we can measure the analytes. And when we measure this analyte in our body fluids, we're now able to identify the presence of a particular pathologic disease or sometimes always remember that measuring your analyte doesn't always have to be associated with pathologic diseases. Sometimes we're also pertaining to your physiologic functions. Like take for example for pregnant women, we're monitoring the progress of the pregnancy. If you are taking your therapeutic drugs, we're also monitoring the course of your therapy. So your spectrophotometry is actually being utilized in a lot of areas. So be it in the diagnosis, monitoring and even in the management of our patients. But to encapsulate everything, okay, to encapsulate everything that I want you guys to remember when it comes to spectrophotometry, more specifically your absorption spectroscopy. Again, in absorption spectroscopy, we are measuring the light that is absorbed by a particular analyte so that we can quantify and we can identify its presence in a particular body fluid. So your body fluid could be your, of course, the most commonly used in the laboratory, specifically in the clinical chemistry section is your serum. You can also use your plasma, your whole blood, your urine, other body fluids like your CSF, your effusions or asides and even your amniotic fluid in some cases. So having said that now, before we dig into the principle and the different component of your spectrophotometer, it's rightful for us to talk about the different types of your absorption spectroscopy because there are two. The two absorption spectroscopy are first, your photometric measurement and your spectrophotometric measurement. These two are seemingly one and the same but the reality is they are different from one another. So let's talk about your photometric measurement first. So when you talk about photometric measurement, we are measuring the light intensity without consideration to your wavelength. I have my phone here so if I open my flashlight, the light intensity is being measured. So without consideration if it is coming from the ultraviolet region, from the visible region or even in the infrared region, we're not talking about a specific wavelength here. So with respect to photometric measurement, what we are only measuring is the light intensity. So to give you a better visual of how photometric measurement would look like, this is actually very much related to your nephilometry and also your turbidimetry. Nephilometry and turbidimetry. We are also measuring light intensity there but we're not specific on what wavelength is involved in that particular measurement. Now, when you talk about spectrophotometric measurement, as you can see the root word photo, the word photometric is still here because at the end of the day, we're still measuring light. But the thing is, in your spectrophotometric measurement, when we say spectrum, we're now dividing the light into the spectrum of light. So if you can remember the spectrum of light, you can now identify there the microwave from the ultraviolet to your visible light and also your infrared light. So when we're talking about spectrophotometric measurement, this is now the measurement of light intensity in a narrower wavelength. So when we say narrower wavelength, we are able not to isolate a specific wavelength of interest that we want to use in a particular measurement. So here, it's more like dissecting your light, isn't it? Take, for example, your human body. Take, for example, let's compare your light to the human body. So your human body, it's just generally just your light. Unlike your spectrum of light, we're not trying to dissect your light. So we're now identifying the ultraviolet region, the visible region, and also the infrared region. So that's very important for you guys to remember. So photometric and spectrophotometric measurement. Now that we are able to talk about absorption spectrophotometry and focusing now to your spectrophotometric measurement, maybe one question that you have in mind is that, okay, sir. Now spectrophotometric measurement means I measure the light intensity coming from a narrower wavelength. But how would you be able to explain its relationship with concentration? Why are you saying that when I do my spectrophotometric measurement, I can qualitatively and I can even identify or measure may analytes qualitatively or quantitatively. So how come, okay, that in itself now can be explained by the law, okay, which we call your beer's law. We're not talking about your beer, okay. It's too early for your beers for today. So lesson first. So your beer's law is the law or the principle that governs your spectrophotometry. So beer's law was first discovered by beers and lumber. So these are the scientists who discovered your beer's law or rather who explained your beer's law. So your beer's law states that the concentration of a particular substance, when we talk about concentration of a particular substance, we're talking about now your analytes, your biomolecules, the one that you're trying to measure in the laboratory. So beer's law states that the concentration of the substance is directly proportional to the amount of optical density. And please take note, optical density is synonymous with absorbance, okay. So what do you mean by absorbance? This is the absorbance photometry now, spectrophotometry. This is now the amount of light that is absorbed by your substance, okay. And according to beer's law, your concentration is directly proportional to the optical density or absorbance. If I may say it in Filipino, ladies and gentlemen, ang ibig nating sabihin kung gano ka dami yung substance na lang dun sa solution, ganun din ka dami yung na-absorb niyang light energy from the light source, okay. So again, the concentration of your substance is directly proportional to the optical density. Okay, they are directly proportional to the optical density or the absorbance of your substance. Contrary, okay, aside from that, your beer's law also states that aside from your concentration and your absorbance or your optical density, another player is your logarithm of transmitted light also known as your transmittance or in other references, you can read it as your percent transmittance. So what do we mean by that? So your concentration is inversely proportional to the transmitted light. It just makes sense because the more light that is being absorbed by your substance, the less light that is, the lesser light is to be transmitted from the system. So for you to be able to understand that better, so let us go to a particular illustration here. And by the way, I can also send you guys assimilation of the beer's law so that you'll be able to understand it better. For my students, I already uploaded that in our TLC. So you will be in the laboratory part, so you'll be able to somehow manipulate the assimilation so that you can see clearly the relationship between your concentration, your absorbance, and also your percent transmittance, okay. Now moving forward, okay. Take for example, this is your, the red one is your cuvette or your sample set. So the absorbance is the amount of light that is absorbed obviously of our substances. So again, as we mentioned, the absorbance is directly proportional to your concentration. The A there stands for absorbance and the C stands for concentration. So they are directly proportional. So before we dig into your transmittance, let me just first explain your molar absorptivity and your path length, okay. So if you're reading your bishop chapter five, now if you're reading your bishop chapter five, molar absorptivity is defined as the characteristic of your substance, okay. Nagaracteristic of your absorb, of your substance to absorb a particular specific fraction of the wavelength, okay. So what we're trying to say here is that your molar absorptivity vary from one analyte from the other. Just like now when you go to your laboratory, the wavelength that you will be using in your glucose is different from your cholesterol, different from your creatinine, and even different from your hemoglobin. Because again, this substance has, this substance they all have different molar absorptivity, okay. And your molar absorptivity in this case, in your beer's law, it is actually constant, okay. It is actually constant. So no need to actually bother thinking about how are you going to compete your molar absorptivity because this one's constant. On the other hand, we also have your B. What is B? B is your path length, okay. What do we mean by your path length? Path length now, this is the length that you're, the light needs to travel through your solution, okay. And most of the time it is dependent on your sample cell or in your cuvette. So this is just simply the distance, okay. So from this point, take for example, I don't know if you can see my cursor right now, but from this point, from one end of the container to the other, that is your path length. So let me take an example, take for example, I hope you guys can see this one. So the path length here, if I'm going to measure the path length, so the width, okay, the width that the light need to traverse through your sample cell or through your solution that is your path length. And for most of our cuvette, as you all know, for most of our sample cell, that is also constant, okay. That is also constant. That's why both your molar absorptivity and your path length, since they are both constant, we can simply cancel them out. And now what we're left with us is your absorbance and your concentration. And again, according to Beerslow, your absorbance is directly proportional to your concentration. The higher the concentration of the substance is in your solution, the more light will be absorbed by this substance. So take for example, you're measuring the glucose for diabetic patient and you know that the glucose levels are increased, the more light will also be absorbed in that solution. And let's now put into the equation your percent transmittance, okay. Your percent transmittance, as we said, is inversely proportional to your absorbance and also to your concentration. It's simple, okay. And it's simplest form, okay. The more light that is absorbed, okay. The more light that is absorbed by your solution, the lesser light will be transmitted, okay. The lesser light will be transmitted. Like like for example, let me turn on again my flashlight. If I have my flashlight here, okay. I have my flashlight and then I block it, okay. I block it with a translucent cover of my notebook, okay. As you can see, okay, hopefully you can see it on your screen. Although I doubt, okay. So if you guys could see, if you guys could see, okay, there's still some light that is being transmitted or being transmitted through the, take for example, if this is your sample cell, there's still a portion of light that is passing through your sample cell. So that would mean that there is only a little amount of light that is being absorbed here. Unlike if you completely have a solution here, as you can see, there is no longer light being transmitted. Why? Because ideally I'm just, I'm just making an illustration for you guys to understand it better, no. So as you can see, when all the light is absorbed, or there is already 0% transmittance, okay. Meaning to say, there is no other or no remainder, there is no light, okay, that is being transmitted through your solution, okay. So again, it is a very important concept about your look and about spectrophotometry that you guys need to remember because at the end of the day, because at the end of the day, when it comes to your spectrophotometer, you will only be able to understand the reason how are we able to compute or calculate for the concentration of a particular analyte when you understand the relationship between absorbance and your transmittance. In mind you, okay, later on as we move along, you'll see your photodetector, you'll see some of the components that are actually computing, that are actually computing so that you'll be able to have your absorbance, okay, your absorbance reading. So I hope I made myself clear with that. So moving on, okay, this is now on your screen, if you guys could see, okay, if you guys could see on your screen there, I'll just have to enlarge myself so I can reach that, okay. So here as you can see, on the, if you're facing your screen, this is the left side of your screen, the left side of your screen, these are the different components of your spectrophotometer. This came from, this illustration came from MacPherson, the Henry's Clinical Laboratory Book, okay. So you have here your light source, okay, you have your light source and together you have your monochromator, your monochromator which is composed of your entrance lit, the monochromator itself and also your exit slit. You have your sample cell or your qubit and then your photodetector and of course your readout device which is commonly now, okay. The most commonly used readout device now are light emitting diode or LED display unlike before they have an analog dial that would indicate the absorbance. So for us to be able to understand and to read somehow for some of you if you have already read about spectrophotometer, this will just be a refresher, a review about your spec, the different components of your spectrophotometer. So the first one of course are your light source. So let's talk about your light source first. So light source obviously, they are the one that provides the energy or the light energy, the radiant energy that our system will be using, okay. So the light source provide the energy that the sample will modify or attenuate by absorption. So remember that your, remember that this light that we are using again depends on a particular analyte. So they vary from one, they vary from different analyte. So the usual light that we are using are polychromatic light. So when we say polychromatic light, it include all visible wavelength. So from 400 nanometer to 700 nanometer. So that is what we mean by polychromatic light, okay. When we say polychromatic light, entire light spectrum is included. So remember that your visible light, your visible light is from 400 to 700 nanometer. So less than 400 nanometer that is your ultraviolet light and greater than 700 nanometer that is now your infrared light, okay. So again, your light source is the one that provides the incident light for your system. To understand more your light source, there are different types of light source that are being used in the laboratory. Depending on what specific region they are, what specific region in the light spectrum are they providing? Do they provide your infrared light, your visible light, your ultraviolet light or do they provide all of those wavelength? We'll see on the succeeding slides. So again, okay. Again, when we talk about your, when we talk about your light source, not only do they provide the system, the light for your system, they can also be classified into two. We have your continuum light sources and we have your line sources. So between the two, which one is most commonly used? Of course that would be your continuum light sources, okay. Your continuum light sources. An example of your continuum light sources now are your incandescent tungsten or your tungsten iodide lab. So this is the most common light source being used because they do not just provide a specific wavelength, but they provide a wide or a vast array of wavelength for our laboratory. So they provide visible to near infrared region. Okay, so most of the time we're using your tungsten or your incandescent tungsten because they provide us the visible region and also the infrared region. Hopefully guys, when I am saying visible region, we're connecting. When I say visible region, this is from 400 to 700 and infrared that is greater than 700 nanometer, okay. Now, aside from that, we also have alternatives because in the laboratory, as you all know, we are also are using your ultraviolet spectrum. So if you guys can remember, we are using 314 nanometer, 360 nanometer, most especially for enzymatic reactions, for some enzymatic reactions. So in that case, we can use your mercury arc lamp, your deuterium lamp, your hydrogen lamp that would provide us a UV spectrum or ultraviolet region of light. We can also use your mercury arc lamp again as an infrared that would provide us an infrared spectrum or infrared region. You can also use your nurse blower or your glober lamp that would also provide you your infrared light or your infrared region, okay. So it's very important for us to remember this because again, in the laboratory, if you're trying to establish your lamp, you need to you need to also consider the light source, specifically the spectrum or the region that they will be providing if you are going to use these types of light sources. So in addition to that, in addition to that, your light source again is crucial in the laboratory because your light source, they are the one, of course, obviously that in other books anyways, by the way, your light source is also referred to as your exciter lamp, okay. Your exciter lamp. Although I seldom use the term exciter lamp because that would be more appropriate for your atomic absorption and your fluorometry. So having said that, let's move forward to the next component of your spectrophotometer. So we have your entrance slit, your monochromator, and your exit slit. As already has now, pause. And I want you guys to remember that your entrance slit, okay, that is entrance, entrance slit, your monochromator and your exit slit. This three affects the degree of wavelength isolation. So what is the purpose of your entrance monochromator and your exit slit? Let's move on to our next slide for you to find out. So your entrance slit, remember, your entrance slit is the opening of your monochromator, okay. In some books, in some books, your entrance slit, your monochromator and your exit slit, they are as one, okay. They are referred to as one on textbook as well. They are being discussed separately. So for the sake of understanding the importance of your monochromator, I'll discuss them separately, okay. So your entrance slit, okay, your entrance slit minimizes your stray light, okay. So it prevents the entrance, okay, of any scattered light. So any scattered light, like take for example, I only want to isolate the light coming from my light source. So for me to be able to do that, I need to eliminate other light coming from the environment or coming from the system or coming from any other sources other than my light source, okay. Are we clear? So what you just want to isolate or what you just want to concentrate into is the light coming from your specific light source. So you want to eliminate the light or the immediate energy that are coming from other sources in the system. So for you to be able to do that, you need your entrance slit, okay. Your entrance slit is just like an entrance gate, okay, that only a specific person or a specific person can enter into that gate, okay. And all other all other person will not be allowed inside or to pass through that specific gate. So what is in our case in your spectrophotometer, what are we trying to prevent? What are we trying to prevent? That's why we are using your entrance gate. We're preventing the entry of your stray light. So what are stray light? So stray light or any light that this refers to any light outside the wavelength that wavelength of your interest, okay. So from your again, your stray light, okay, your stray light are any other light that is coming from other sources except from your light source. So your stray light needs to be removed, okay, your stray light needs to be removed because the present of stray light in the system can cause absorbance error. And if there are absorbance error, of course your concentration would be erroneous, your measurement would be erroneous, your diagnosis would be erroneous, your results will be erroneous as well, okay. So you need to prevent any stray light from coming into or getting into your spectrophotometric system. Now, after your entrance gate, of course the highlight now of your monochromator is the monochromator itself. So your monochromator is used to isolate an individual wavelength of light. So as you can see it is used to isolate a specific wavelength of light and it's very important for you guys to remember what specifically does your monochromator do, okay. So from a polychromatic light, remember your polychromatic light, take for example you have a light source that ranges from the ultraviolet up until your infrared region. But you only need a particular wavelength around let's say 540 nanometer. Take for example that's the wavelength being used in hemoglobin. So you only want 540 nanometer. So you only want to isolate that specific wavelength. So what you're going to use is your monochromator. So from a polychromatic light, it would dissect the light into the light spectrum and then it can now isolate an individual wavelength. So the degree again of your wavelength isolation is affected by those three factors, your monochromator and the weed of your entrance and your exit slit. Please do remember that your monochromator can be in the form of your color glass filters your prisms. Your prisms is very much common because if you guys would know, if you guys would remember Newton was also able to identify the light spectrum through a prism. So when a polychromatic light pass through your prism, it actually dispersed, it actually was dissected into the light spectrum that we all know now this day. So that is your prism. So you can use your prism as your monochromator. But in the laboratory, the most specific and actually the most commonly used monochromator are your diffraction gratings. Diffraction gratings have, diffraction gratings allow us to specifically isolate the wavelength of entrance because as the light bounces back and forth enter diffraction grating, it is able now to isolate only the light that you want and only the light that you need for your measurement. Only the light that you need for your measurement. Now, having said that, take for example, okay we're good sir, we're able to prevent the stray light from entering, we're also able to isolate only the wavelength I want for my measurement. Now what's next? We're now going to your exit slit. So your exit slit now controls the light beam or the width of your light beam or your band pass. Again the width of your band pass is important. Okay, the width of your band pass is important to be constant because it would affect your molar absorptivity. The one that we discussed in Bear's Law. So for us to be able to make sure that the molar absorptivity is constant, we also need to make sure that the exit slit the width of the band pass or the light beam is also constant. So in this case, another thing that your exit slit does is that it allows only now the fraction of the spectrum to reach the sample qubit. What do you mean by this? It only allows so take for example, there are um you were able to have your visible region inside your monochromator but the only one that would pass through the exit slit is the wavelength of interest. The 540 nanometer that we're talking about. So that's the only fraction of the spectrum that would pass through the exit slit and reach your sample qubit. So again one good consideration when it comes to your exit slit is that the narrower the band pass, the greater resolution we can have. So meaning when the width or the band pass is lower or narrower we're able to have higher resolution or rather a greater resolution or a more specific isolation of your wavelength or of your light. So please do remember that. So to encapsulate everything when it comes to your monochromator again you have your entrance slit, you have your monochromator and of course you also have your exit slit. So again remember those three because they affect the degree of your wavelength isolation by preventing your stray light by isolating the specific wavelength from your polychromatic light and by increasing the resolution by regulating the band pass of your light. Now of course now that we are through with your light source and your monochromator here comes now your sample slit. Your sample slit in its simplest definition it is the one that holds your solution okay if for example you want to measure your glucose in the serum. This sample slit is the one that would hold your serum together with your reagents okay together with your reagents. So your sample cell is also known as your cubit or your analytical cell so you can refer to it as your cubit analytical cell or your sample cell depending on the reference that you are using but again all of those three are just simply synonymous. So sample cell holds the solution of which the absorption is to be measured. So remember one consideration that you guys need to remember about sample cell is the path length. The path length again needs to be constant so that when you measure your absorption molar absorptivity is constant even the path length is constant. So path length is actually the distance where light need to pass through from your solution. If I'm going to get my example again okay so here here's my example so from this point going to this point that would be your path length. So if this is a cubit that is also its path length okay that is the path length of your system okay so in addition to that okay in addition to that a quick reminder to everybody if you're reading your bishop and your Henry's please do remember that the most commonly used sample cell are your rectangular sample cell. Why rectangular sample cell again I'll go back to path length okay. It's easier to standardize the path length when you are using a rectangular when you are using a rectangular sample cell or cubit rather than using a circular cubit or a cylindrical cubit because it's hard to standardize the diameter compared to standardizing the width or the sides of your rectangular cubit. So what I'm trying to say that always remember that in the laboratory we're usually using we're usually using a rectangular cubit. We're not even fond of using your test tube as the sample cell in the solution because again um I'll say it in Tagalog no iba-ibayong kapal niya okay the thickness of your test tube may vary okay there are test tube that are very thin some are thicker so that would be a problem when it comes to your path length. So again to better standardize that what we're using is your rectangular sample cell sample cell that holds your solution sample cell that could also be known as your cubit in your analytical cell. Now moving forward we're actually near to the end of our discussion so after your sample cell of course you have your photo detector. Your photo detector in its simplest definition is the one that converts the radiant energy to its equivalent electrical energy that would now be transmitted through your readout device. So remember that your light source gives out a light energy radiant energy as it pass through your end translate monochromator exit lead and then your sample cell there is now the light being transmitted or the percent transmittance okay the percent transmittance the light that is being um the light that is being um transmitted there will now be converted to your electrical energy. Sir is that possible yes that is possible through your photo detector. So in physics remember the law of conservation of mass and energy so light energy can be converted to um heat light energy can be converted to other forms of energy in this case it is being converted or being transmitted to uh rather it is being converted to your electrical energy so the radiant energy or the transmitted light okay that pass through your sample will now be converted to an electrical energy okay again it will now be um converted to your electrical energy and that electrical energy is the one that will be quantified by your photo detector and will now be delivered by your readout device okay that will now be delivered or be read and be displayed by your readout device but before we go further remember that your photo detector i will only be discussing the most common or the most sensitive and specific photo detector being used but be mindful that there are also other types of photo detector you can have your photo cell, your photo tube your photo transistor or photo diode your photo multiplier tube and your barrier layers your barrier layers I just want you guys to remember that among this five the simplest type of photo detector again the simplest type of photo detector are your barrier layer cell okay your barrier cell or your barrier layer cell again that is the simplest type of photo detector but that's not what we're after we're after the most sensitive and the most specific photo detector and that would be your what that would be now your photo multiplier tube or your PMT your photo multiplier tube is the most common type of photo detector being used specifically for visible and for ultraviolet right be mindful that your photo multiplier tube is also the photo detector choice for your atomic absorption spectrophotometry and even your fluorometry why because your photo multiplier tube is very specific and is very sensitive why because it is able to detect very low light very low level of light and quick burst of light quick burst of light that are related to atomic absorption spectrophotometry low level of light that could be related to your spectral even in your fluorometry so here niba a very minute amount of light can be detected by your photo multiplier tube so the sensitivity is really excellent so what do you mean by sensitivity or analytical sensitivity it is the ability of your method to identify the lowest amount of your analyte the lowest amount of your analyte so sometimes you are unable to measure the analyte because of its very low concentration a very good example of this are your enzymes remember that your enzymes are being measured not by concentration but actually by activity because of their low concentration in our blood so your photo multiplier tube is a good photo detector because of its excellent sensitivity and rapid response rapid response because it can identify quick burst of light like take for example so the quick burst of light so as the light flicker it can actually measure that very quick burst and very low level of light because your photo multiplier by its name photo multiplier what do we mean by photo multiplier tube it is incapable of amplifying your radiant energy up to 200 times what do you mean by photo multiplier the light the very tiny the very low level of light and the quick burst of light that was transmitted and was detected by your photo detector your photo multiplier in this case can now be amplified up to 200 times okay so by its name photo the light is being multiplied or being amplified up to 200 times so that your machine now can now identify it my illustration here is not working but it's actually a GIF so remember you have your dienodes there okay you have your dienode so as your light enter okay from the left as the light enter the first dienode okay it will pass through it will bounce to your first dienode back and forth as it traverse at it traverse your photo multiplier tube it is now being amplified or multiplied up until 200 up until 200 times its original original concentration or original level okay so this is very important because it enable us now to identify and to measure very low level of light and quick burst of light so that is very important when it comes to spectrophotometry because at the end of the day even if you properly calibrated your monochromator if your photo detector cannot properly detect and transmit or convert your radiant energy to its equivalent electrical energy there would be errors in your results now finally after your photo multiplier tube of course we have now your readout device so your readout device it displays the output of the detection system so it could be in a form of your galvanometer or your ammeter the one on your right if you're facing your screen so this is the old spectrophotometer they have a galvanometer and ammeter that would that would point out there that would point out to the specific transmittance or absorbance of your solution but now we actually have your light emitting diode or your LED display which enable us to read the absorbance easier and faster okay so in general that is actually the different components okay the different components of your spectrophotometer you have your light source okay let's just try to wrap it up all together before we end you have your light source the most common we use is your incandescent tungsten okay your light source that provide the radiant energy for your system you have your monochromator your entrance lead, your monochromator and your exit lead the specificity of wavelength isolation from a polychromatic light to a specific spectrum of light and then you have your sample cell other name for sample cell are together with me you have your quvet or your analytical cell so it holds the solution that will be measured and aside from that please remember that the most commonly used type of quvet in the laboratory are your rectangular quvet second and then next is your photo detector the most common photo detector used in the laboratory are your photo multiplier too because they are excellent they have excellent sensitivity aside from that aside from their excellent sensitivity they can also identify quick burst of light and very low level of light and finally of course you also have your readout device so with that thank you so much for listening so if you have any questions or clarification you may send me a message so I will be able to answer them so these are my references so thank you so much for thank you so much for listening and before I leave I just want to leave a quote from Zieg Ziegler it is your attitude more than your aptitude that will determine your attitude have a great day