{"id":12849,"date":"2026-06-22T15:30:11","date_gmt":"2026-06-22T15:30:11","guid":{"rendered":"https:\/\/www.vedprep.com\/exams\/?p=12849"},"modified":"2026-06-22T15:34:21","modified_gmt":"2026-06-22T15:34:21","slug":"chromatography-techniques","status":"publish","type":"post","link":"https:\/\/www.vedprep.com\/exams\/iit-jam\/chromatography-techniques\/","title":{"rendered":"Chromatography techniques: IIT JAM 2027"},"content":{"rendered":"<p><span style=\"font-weight: 400;\">The topic of <\/span><b>Chromatography techniques<\/b><span style=\"font-weight: 400;\"> is a huge slice of the syllabus for competitive exams like CSIR NET and IIT JAM. If you look at the official breakdown, it sits right under Paper 1, Section 2 (Chromatography and Spectroscopy) for IIT JAM, and a similar slot for CSIR NET.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">At its core, chromatography is just a set of lab methods used to separate, identify, and count the pieces of a mixed-up sample. It is a staple in chemistry labs, biology setups, and pharma companies. If you want to dig into the heavy theory, standard textbooks like <\/span><i><span style=\"font-weight: 400;\">Organic Chemistry<\/span><\/i><span style=\"font-weight: 400;\"> by J.D. Lee and <\/span><i><span style=\"font-weight: 400;\">Physical Chemistry<\/span><\/i><span style=\"font-weight: 400;\"> by P. W. Atkins cover the basics well. But for the exam, you need to know how these systems work in practice, the different types (like gas and liquid chromatography), and where they are actually used. Mastering these ideas is what gets you those crucial marks.<\/span><\/p>\n<h2><b>Understanding Chromatography Techniques for IIT JAM: A Core Concept<\/b><\/h2>\n<p><span style=\"font-weight: 400;\">Let\u2019s strip away the textbook definitions for a second. Imagine you dump a bag of multi-colored chocolate candies into a bowl of warm water. Some colors dissolve and spread instantly, while others take their sweet time. Chromatography works on a similar wavelength. It is all about how the components of a mixture divide themselves between two phases: a <\/span><b>stationary phase<\/b><span style=\"font-weight: 400;\"> (the one staying put) and a <\/span><b>mobile phase<\/b><span style=\"font-weight: 400;\"> (the one on the move).<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The stationary phase can be a solid or a liquid, and the mobile phase is usually a liquid or a gas. When you flush your mixture through the system, the different parts play a game of tug-of-war between the two phases. If a component prefers the mobile phase, it zips right through. If it likes the stationary phase better, it lags behind. This difference in speed is what separates them.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Here is a quick look at the main <\/span><b>chromatography techniques<\/b><span style=\"font-weight: 400;\"> you will run into:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Paper chromatography:<\/b><span style=\"font-weight: 400;\"> Uses a special strip of paper as the stationary phase.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Thin layer chromatography (TLC):<\/b><span style=\"font-weight: 400;\"> Uses a sleek glass or plastic plate coated with a thin layer of silica gel or alumina.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Gas chromatography (GC):<\/b><span style=\"font-weight: 400;\"> Uses a gas to push the mixture through a column.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Liquid chromatography (LC):<\/b><span style=\"font-weight: 400;\"> Uses a liquid solvent to move the sample along.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Supercritical fluid chromatography (SFC):<\/b><span style=\"font-weight: 400;\"> Uses a highly pressurized supercritical fluid (like dense CO<sub>2<\/sub>) as the mobile phase.<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">To ace <a href=\"https:\/\/jam2026.iitb.ac.in\/files\/syllabus_BT.pdf\" rel=\"nofollow noopener\" target=\"_blank\"><strong>IIT JAM<\/strong><\/a>, you need to know which method fits which scenario. For example, GC is your go-to for volatile stuff that turns into vapor easily, while LC handles the heavy, non-volatile molecules.<\/span><\/p>\n<h2><b>Worked Example: Solved Question on Chromatography Techniques For IIT JAM<\/b><\/h2>\n<p><span style=\"font-weight: 400;\">Let&#8217;s look at a classic problem you might see in <strong>Chromatography techniques<\/strong>.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Imagine a fictional lab scenario where an analyst wants to separate a mixture of caffeine and theophylline using paper chromatography. They run the experiment using a mix of water and an organic solvent. After the run, the solvent front moves 10 cm. The caffeine spot travels 6 cm, and the theophylline spot travels 4 cm.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The R<sub>f<\/sub> value (Retention Factor) is just the ratio of how far the compound traveled compared to how far the solvent traveled. Let&#8217;s calculate them:<\/span><\/p>\n<p><img loading=\"lazy\" fetchpriority=\"high\" decoding=\"async\" class=\"alignnone wp-image-24370 aligncenter\" src=\"https:\/\/www.vedprep.com\/exams\/wp-content\/uploads\/Retention-Factor-300x87.png\" alt=\"Retention Factor\" width=\"479\" height=\"139\" srcset=\"https:\/\/www.vedprep.com\/exams\/wp-content\/uploads\/Retention-Factor-300x87.png 300w, https:\/\/www.vedprep.com\/exams\/wp-content\/uploads\/Retention-Factor-768x223.png 768w, https:\/\/www.vedprep.com\/exams\/wp-content\/uploads\/Retention-Factor.png 936w\" sizes=\"(max-width: 479px) 100vw, 479px\" \/><\/p>\n<h3><b>Separation Summary Table<\/b><\/h3>\n<table style=\"width: 28.5112%;\">\n<tbody>\n<tr>\n<td style=\"width: 58.0311%;\"><b>Compound<\/b><\/td>\n<td style=\"width: 143.005%;\"><b>Rf\u200b Value<\/b><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 58.0311%;\"><b>Caffeine<\/b><\/td>\n<td style=\"width: 143.005%;\"><span style=\"font-weight: 400;\">0.6<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 58.0311%;\"><b>Theophylline<\/b><\/td>\n<td style=\"width: 143.005%;\"><span style=\"font-weight: 400;\">0.4<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-weight: 400;\">What does this tell us? The distribution coefficient (K) measures the concentration ratio between the two phases. A higher R<sub>f<\/sub> value means the compound tracks closely with the mobile phase. So, our math shows that caffeine interacts more with the mobile solvent than theophylline does, letting it move faster up the paper.<\/span><\/p>\n<h2><b>Common Misconceptions about Chromatography Techniques<\/b><\/h2>\n<p><span style=\"font-weight: 400;\">A lot of students get tripped up by a few common myths when studying <strong>Chromatography techniques<\/strong>.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">First, many think chromatography is only for <\/span><i><span style=\"font-weight: 400;\">qualitative<\/span><\/i><span style=\"font-weight: 400;\"> analysis\u2014like checking if a compound is present or not. That is wrong. Modern setups do both qualitative and quantitative work perfectly. They tell you <\/span><i><span style=\"font-weight: 400;\">what<\/span><\/i><span style=\"font-weight: 400;\"> is in your beaker and exactly <\/span><i><span style=\"font-weight: 400;\">how much<\/span><\/i><span style=\"font-weight: 400;\"> of it is there.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Another trap is thinking that Gas Chromatography is the only type that matters for the exam. While GC is important, IIT JAM tests a whole spread, including LC, TLC, and High-Performance Liquid Chromatography (HPLC).<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Finally, do not let the jargon scare you into thinking this is too complex or tedious to learn. Once you look past the fancy instrument names, it always comes down to the same basic interaction between a stationary phase and a mobile phase. Breaking it down this way makes the whole topic way friendlier.<\/span><\/p>\n<h2><b>Application of Chromatography Techniques in Real-World Scenarios<\/b><\/h2>\n<p><span style=\"font-weight: 400;\">To see why <b>chromatography techniques <\/b>matter, let&#8217;s look at how these methods work outside the exam hall.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">In the pharma world, quality control is everything. Companies rely on HPLC and GC to check the purity of drugs before they hit the shelves. It helps them spot tiny amounts of impurities or contaminants, making sure the active ingredients are safe and at the right dosage.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Environmental teams also use these tools to protect our air, water, and soil. For instance, Gas Chromatography-Mass Spectrometry (GC-MS) acts like a chemical detective, identifying volatile organic pollutants in air samples to help enforce safety laws.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Even the food industry depends on these methods. Labs use HPLC and Ultra-Performance Liquid Chromatography (UPLC) to check what is in our food, scanning for hidden pesticides, heavy metals, or illegal artificial dyes to make sure grocery store items are safe to eat.<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Pharma labs:<\/b><span style=\"font-weight: 400;\"> Checking drug purity and safety via HPLC and GC.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Eco-monitoring:<\/b><span style=\"font-weight: 400;\"> Hunting down pollutants with GC-MS.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Food safety:<\/b><span style=\"font-weight: 400;\"> Spotting pesticides and tracking additives using HPLC and UPLC.<\/span><\/li>\n<\/ul>\n<h2><b>Exam Strategy: Tips and Important Subtopics for Chromatography Techniques for IIT JAM<\/b><\/h2>\n<p><span style=\"font-weight: 400;\">Getting a handle on <\/span><b>chromatography techniques<\/b><span style=\"font-weight: 400;\"> can feel a bit overwhelming when you are staring at a massive syllabus. The trick is to focus heavily on the underlying physical chemistry principles, like the differences between adsorption, partition, and ion-exchange mechanisms.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Make sure to get plenty of practice with problems based on paper, thin layer, and gas chromatography calculations. You will want to be comfortable comparing high-end methods like HPLC and GC-MS too. We at <a href=\"https:\/\/www.vedprep.com\/online-courses\"><strong>VedPrep<\/strong> <\/a>find that mapping out these methods side-by-side helps the differences stick.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">When you sit down to study, try structuring your notes around these high-yield areas:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The core physical principles of phase separation<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Different separation mechanisms (adsorption vs. partition vs. ion exchange)<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Real-world applications of advanced setups (HPLC, GC-MS)<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The math behind basic methods (calculating R<sub>f<\/sub> values in paper and TLC)<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">At <strong><a href=\"https:\/\/www.vedprep.com\/online-courses\/iit-jam\">VedPrep<\/a><\/strong>, we pull together video breakdowns, targeted practice questions, and mock tests designed to make these exact topics feel like second nature. Taking a steady, step-by-step approach to practicing these problems will help you walk into the exam room feeling completely ready.<\/span><\/p>\n<h2><b>Types of Chromatography Techniques for IIT JAM: A Comprehensive Overview<\/b><\/h2>\n<table>\n<tbody>\n<tr>\n<td><b>Chromatography Type<\/b><\/td>\n<td><b>Stationary Phase<\/b><\/td>\n<td><b>Mobile Phase<\/b><\/td>\n<td><b>Main Separation Mechanism<\/b><\/td>\n<\/tr>\n<tr>\n<td><b>Paper<\/b><\/td>\n<td><span style=\"font-weight: 400;\">Liquid (Water trapped in paper fibers)<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Liquid solvent<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Partition<\/span><\/td>\n<\/tr>\n<tr>\n<td><b>Thin Layer (TLC)<\/b><\/td>\n<td><span style=\"font-weight: 400;\">Solid (Silica gel or Alumina on a plate)<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Liquid solvent<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Adsorption<\/span><\/td>\n<\/tr>\n<tr>\n<td><b>Gas (GC)<\/b><\/td>\n<td><span style=\"font-weight: 400;\">Liquid or Solid coated inside a column<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Inert gas (like Helium or Nitrogen)<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Partition or Adsorption<\/span><\/td>\n<\/tr>\n<tr>\n<td><b>High-Performance Liquid (HPLC)<\/b><\/td>\n<td><span style=\"font-weight: 400;\">Solid packing material inside a column<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Liquid solvent under high pressure<\/span><\/td>\n<td><span style=\"font-weight: 400;\">Adsorption or Partition<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2><b>Additional Study Tips for Mastering Chromatography Techniques for IIT JAM<\/b><\/h2>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Visualize the process:<\/b><span style=\"font-weight: 400;\"> Do not just memorize the tables. Picture the mobile phase moving up a plate or through a column. Visualizing the molecular tug-of-war makes it easier to predict how changing a solvent will affect your results.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Watch the units:<\/b><span style=\"font-weight: 400;\"> When calculating R<sub>f<\/sub> values or retention times, ensure your units match up perfectly before doing any division. It sounds simple, but it is an easy place to drop silly marks under exam pressure.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Relate it to lab work:<\/b><span style=\"font-weight: 400;\"> If you did any TLC or column runs during your BSc lab classes, think back to those experiments. Connecting the textbook theory to a real glass plate you held in your hand makes the concepts stick much better.<\/span><\/li>\n<\/ul>\n<section>\n<h2><strong>Final Thoughts\u00a0<\/strong><\/h2>\n<p>Mastering <b data-path-to-node=\"0\" data-index-in-node=\"30\">chromatography techniques<\/b> isn&#8217;t about memorizing every tiny detail of a massive instrument layout\u2014it\u2019s about understanding that simple molecular tug-of-war between two phases. Once you get comfortable with how different compounds partition themselves, the exam questions start looking a lot less intimidating. Just take it step-by-step, practice those <span class=\"math-inline\" data-math=\"R_f\" data-index-in-node=\"382\">R<sub>f<\/sub><\/span><sub>\u00a0<\/sub>calculations, and focus on the fundamental principles.<\/p>\n<p>To know more in detail from our faculty, watch our YouTube video:<\/p>\n<p class=\"responsive-video-wrap clr\"><iframe title=\"Chromatography Explained | Lecture 1 | Techniques Series | CUET PG, CSIR NET, IIT JAM,GATE 2026\" width=\"1200\" height=\"675\" src=\"https:\/\/www.youtube.com\/embed\/u3iasKEn3Bg?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<h2><strong>Frequently Asked Questions<\/strong><\/h2>\n<\/section>\n<style>#sp-ea-24373 .spcollapsing { height: 0; overflow: hidden; transition-property: height;transition-duration: 300ms;}#sp-ea-24373.sp-easy-accordion>.sp-ea-single {margin-bottom: 10px; border: 1px solid #e2e2e2; }#sp-ea-24373.sp-easy-accordion>.sp-ea-single>.ea-header a {color: #444;}#sp-ea-24373.sp-easy-accordion>.sp-ea-single>.sp-collapse>.ea-body {background: #fff; color: #444;}#sp-ea-24373.sp-easy-accordion>.sp-ea-single {background: #eee;}#sp-ea-24373.sp-easy-accordion>.sp-ea-single>.ea-header a .ea-expand-icon { float: left; color: #444;font-size: 16px;}<\/style><div id=\"sp_easy_accordion-1782141883\">\n<div id=\"sp-ea-24373\" class=\"sp-ea-one sp-easy-accordion\" data-ea-active=\"ea-click\" data-ea-mode=\"vertical\" data-preloader=\"\" data-scroll-active-item=\"\" data-offset-to-scroll=\"0\">\n\n<!-- Start accordion card div. -->\n<div class=\"ea-card ea-expand sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-243730\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse243730\" aria-controls=\"collapse243730\" href=\"#\"  aria-expanded=\"true\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-minus\"><\/i> What is the most basic principle behind all chromatography techniques?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse collapsed show\" id=\"collapse243730\" data-parent=\"#sp-ea-24373\" role=\"region\" aria-labelledby=\"ea-header-243730\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span class=\"\">At its heart,<\/span><span class=\"\"> chromatography is a molecular tug-of-war.<\/span><span class=\"\"> A mixture is introduced into a system with two phases:<\/span><span class=\"\"> a stationary phase (which stays put) and a mobile phase (which moves).<\/span><span class=\"\"> Components separate because they have different affinities for each phase.<\/span><span class=\"\"> If a molecule prefers the mobile phase,<\/span><span class=\"\"> it moves fast; if it prefers the stationary phase,<\/span><span class=\"\"> it lags behind.<\/span><\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-243731\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse243731\" aria-controls=\"collapse243731\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What is the main difference between adsorption and partition chromatography?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse243731\" data-parent=\"#sp-ea-24373\" role=\"region\" aria-labelledby=\"ea-header-243731\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span class=\"\">It comes down to how the stationary phase behaves.<\/span><span class=\"\"> In <\/span><b class=\"\" data-path-to-node=\"6\" data-index-in-node=\"54\">adsorption chromatography<\/b><span class=\"\">,<\/span><span class=\"\"> the stationary phase is a solid,<\/span><span class=\"\"> and the components physically stick to its surface.<\/span><span class=\"\"> In <\/span><b class=\"\" data-path-to-node=\"6\" data-index-in-node=\"169\">partition chromatography<\/b><span class=\"\">,<\/span><span class=\"\"> the stationary phase is a liquid film supported on a solid,<\/span><span class=\"\"> and the components dissolve into it,<\/span><span class=\"\"> separating based on their relative solubility between the two liquid layers.<\/span><\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-243732\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse243732\" aria-controls=\"collapse243732\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> Why is the stationary phase in paper chromatography considered a liquid?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse243732\" data-parent=\"#sp-ea-24373\" role=\"region\" aria-labelledby=\"ea-header-243732\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span class=\"\">Even though the paper itself is solid cellulose,<\/span><span class=\"\"> it tightly traps a thin layer of moisture (water molecules) within its fibers.<\/span><span class=\"\"> It is this trapped water film that acts as the actual liquid stationary phase,<\/span><span class=\"\"> making paper chromatography a type of liquid-liquid partition chromatography.<\/span><\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-243733\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse243733\" aria-controls=\"collapse243733\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What is reverse-phase chromatography, and how does it differ from normal-phase?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse243733\" data-parent=\"#sp-ea-24373\" role=\"region\" aria-labelledby=\"ea-header-243733\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span class=\"\">Think of reverse-phase as the exact opposite of normal-phase.<\/span><span class=\"\"> In normal-phase,<\/span><span class=\"\"> the stationary phase is polar and the mobile phase is non-polar.<\/span><span class=\"\"> In reverse-phase,<\/span><span class=\"\"> the stationary phase is modified to be non-polar (hydrophobic),<\/span><span class=\"\"> while the mobile phase is polar (like water or methanol).<\/span><span class=\"\"> Reverse-phase is incredibly common in modern HPLC setups.<\/span><\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-243734\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse243734\" aria-controls=\"collapse243734\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> Why do we use a pencil to mark the baseline on a TLC plate instead of a pen?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse243734\" data-parent=\"#sp-ea-24373\" role=\"region\" aria-labelledby=\"ea-header-243734\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span class=\"\">Ink from a standard pen contains organic dyes that will dissolve in the mobile phase and separate right along with your sample,<\/span><span class=\"\"> completely ruining your chromatogram.<\/span><span class=\"\"> Pencil lead is made of graphite,<\/span><span class=\"\"> which is inert and won't move or interfere with the separation.<\/span><\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-243735\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse243735\" aria-controls=\"collapse243735\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What is the purpose of the \"solvent front\" in paper or thin-layer chromatography?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse243735\" data-parent=\"#sp-ea-24373\" role=\"region\" aria-labelledby=\"ea-header-243735\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span class=\"\">The solvent front is simply the furthest point the mobile phase travels up the plate or paper.<\/span><span class=\"\"> It is essential to mark this line before the solvent evaporates because you need its exact distance to calculate your <\/span><span class=\"math-inline\" data-math=\"R_f\" data-index-in-node=\"213\">R<sub>f<\/sub><\/span><span class=\"\">\u00a0values.<\/span><\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-243736\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse243736\" aria-controls=\"collapse243736\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> How do you visualize spots on a TLC plate if the compounds are colorless?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse243736\" data-parent=\"#sp-ea-24373\" role=\"region\" aria-labelledby=\"ea-header-243736\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span class=\"\">Since most organic compounds are colorless,<\/span><span class=\"\"> we use tricks to see them.<\/span><span class=\"\"> The most common methods are placing the plate under a UV lamp (where fluorescent indicators in the silica show dark spots) or exposing the plate to iodine vapors,<\/span><span class=\"\"> which temporarily react with organic compounds to form brown spots.<\/span><\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-243737\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse243737\" aria-controls=\"collapse243737\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What is the fundamental difference between Gas Chromatography (GC) and Liquid Chromatography (LC)?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse243737\" data-parent=\"#sp-ea-24373\" role=\"region\" aria-labelledby=\"ea-header-243737\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span class=\"\">The primary difference is the mobile phase.<\/span><span class=\"\"> GC uses an inert carrier gas (like Helium or Nitrogen) to push vaporized samples through a heated column.<\/span><span class=\"\"> LC uses a liquid solvent mixture to carry dissolved samples through the system.<\/span><\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-243738\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse243738\" aria-controls=\"collapse243738\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> Can GC be used for any chemical sample?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse243738\" data-parent=\"#sp-ea-24373\" role=\"region\" aria-labelledby=\"ea-header-243738\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span class=\"\">No,<\/span><span class=\"\"> GC has limitations.<\/span><span class=\"\"> The sample must be volatile\u2014meaning it can vaporize without decomposing when heated.<\/span><span class=\"\"> Large,<\/span><span class=\"\"> highly polar biomolecules like proteins or DNA will degrade before they turn into a gas,<\/span><span class=\"\"> so they are better suited for liquid chromatography.<\/span><\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-243739\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse243739\" aria-controls=\"collapse243739\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What role does the \"carrier gas\" play in Gas Chromatography?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse243739\" data-parent=\"#sp-ea-24373\" role=\"region\" aria-labelledby=\"ea-header-243739\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span class=\"\">The carrier gas is strictly a transporter.<\/span><span class=\"\"> Unlike the liquid mobile phase in LC,<\/span><span class=\"\"> the gas in GC does not chemically interact with the sample molecules; its only job is to sweep the vaporized solutes down the column.<\/span><\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-2437310\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse2437310\" aria-controls=\"collapse2437310\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What makes High-Performance Liquid Chromatography (HPLC) \"high-performance\"?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse2437310\" data-parent=\"#sp-ea-24373\" role=\"region\" aria-labelledby=\"ea-header-2437310\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span class=\"\">Traditional liquid chromatography relies on gravity to trickle solvent through a column,<\/span><span class=\"\"> which is very slow.<\/span><span class=\"\"> HPLC uses high-pressure pumps to force the liquid mobile phase through columns packed with incredibly tiny,<\/span><span class=\"\"> tightly packed particles.<\/span><span class=\"\"> This massive pressure drastically speeds up the process and yields exceptionally sharp separations.<\/span><\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-2437311\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse2437311\" aria-controls=\"collapse2437311\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What is the main advantage of combining chromatography with Mass Spectrometry (like GC-MS)?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse2437311\" data-parent=\"#sp-ea-24373\" role=\"region\" aria-labelledby=\"ea-header-2437311\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span class=\"\">Chromatography is excellent at separating a messy mixture into individual components,<\/span><span class=\"\"> but it isn't always perfect at identifying exactly <\/span><i class=\"\" data-path-to-node=\"32\" data-index-in-node=\"137\">what<\/i><span class=\"\"> those components are.<\/span><span class=\"\"> By linking it directly to a mass spectrometer (MS),<\/span><span class=\"\"> each separated chunk is instantly smashed and analyzed for its molecular weight and fragmentation pattern,<\/span><span class=\"\"> giving you definitive identification.<\/span><\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-2437312\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse2437312\" aria-controls=\"collapse2437312\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> How does Ion-Exchange Chromatography separate molecules?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse2437312\" data-parent=\"#sp-ea-24373\" role=\"region\" aria-labelledby=\"ea-header-2437312\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span class=\"\">It separates them based on their net charge.<\/span><span class=\"\"> The stationary phase consists of a resin coated with charged groups (either positive or negative).<\/span><span class=\"\"> If the resin is negatively charged (cation exchange),<\/span><span class=\"\"> it binds positively charged molecules while letting negatively charged or neutral molecules wash straight through.<\/span><\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-2437313\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse2437313\" aria-controls=\"collapse2437313\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> How do you elute (wash out) a bound protein from an ion-exchange column?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse2437313\" data-parent=\"#sp-ea-24373\" role=\"region\" aria-labelledby=\"ea-header-2437313\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span class=\"\">You can unstick the molecule by changing the mobile phase.<\/span><span class=\"\"> The two easiest ways are increasing the salt concentration (where salt ions compete for the charged sites on the resin) or altering the pH of the buffer to change the net charge of the molecule,<\/span><span class=\"\"> causing it to lose its grip on the stationary phase.<\/span><\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-2437314\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse2437314\" aria-controls=\"collapse2437314\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> Is chromatography only used to identify substances qualitatively?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse2437314\" data-parent=\"#sp-ea-24373\" role=\"region\" aria-labelledby=\"ea-header-2437314\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span class=\"\">While it is great for identifying what is in a sample (qualitative),<\/span><span class=\"\"> modern systems like HPLC and GC use digital detectors to measure the peak area of each eluting component.<\/span><span class=\"\"> The size of that peak tells you exactly how much substance is present,<\/span><span class=\"\"> making it highly quantitative.<\/span><\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<\/div>\n<\/div>\n\n","protected":false},"excerpt":{"rendered":"<p>Chromatography techniques For IIT JAM involve various methods to separate and identify complex mixtures, including paper chromatography, thin layer chromatography, and gas chromatography. This is crucial for competitive exam students to master.<\/p>\n","protected":false},"author":11,"featured_media":12848,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","rank_math_seo_score":85},"categories":[23],"tags":[7976,7977,7979,7978,2923,2922],"class_list":["post-12849","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-iit-jam","tag-chromatography-techniques-for-iit-jam","tag-chromatography-techniques-for-iit-jam-notes","tag-chromatography-techniques-for-iit-jam-practice","tag-chromatography-techniques-for-iit-jam-questions","tag-competitive-exams","tag-vedprep","entry","has-media"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/posts\/12849","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/comments?post=12849"}],"version-history":[{"count":5,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/posts\/12849\/revisions"}],"predecessor-version":[{"id":24375,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/posts\/12849\/revisions\/24375"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/media\/12848"}],"wp:attachment":[{"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/media?parent=12849"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/categories?post=12849"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/tags?post=12849"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}