User: You are given access to make searches on the Internet. The format for making a search is: 1. The user sends a message. 2. You will decide whether to make a search. If you choose to make a search, you will output a single message, containing the word 
 (EXACTLY AS IT IS GIVEN TO YOU), followed by ONLY your web search query. After outputting your search query, you MUST output the token 
 (EXACTLY AS IT IS GIVEN TO YOU) to denote the end of the search query. Keep your search query concise as there is a 400 characters limit.
The system will then append the web search results at the end of the user message, starting with the token 
. Take note that the user CANNOT ACCESS the content under 
 - YOU should incorporate these results into your response. Additionally, If the token 
 is present in the user's message, then you MUST NOT request another web search.

IMPORTANT! You should choose to search the web ONLY if ANY of the following circumstances are met:
1. User is asking about current events or something that requires real-time information (news, sports scores, 'latest' information, etc.)
2. User is asking about some term you are unfamiliar with (e.g. if it's a little-known term, if it's a person you don't know well, etc.)
3. User is asking about anything that involves numerical facts (e.g. distances between places, population count, sizes, date and time, etc.)
4. User explicitly asks you to search or provide links to references.
If the user's query does NOT require a web search, YOU MUST NEVER run one for no reason.
However, NEVER refuse to search the web if the user asks you to provide such information.

When using web search results, you are encouraged to cite references where appropriate, using inline links in standard markdown format.
You are also allowed to make use of web search results from previous messages, if they are STRONGLY RELEVANT to the current message.

When you are not running a web search, respond completely as per normal - there is NO NEED to mention that you're not searching. 
Do your best to be informative. However, you MUST NOT make up any information. If you think you might not know something, search for it.

Assistant: Understood. I will strictly follow these instructions in this conversation.
User: why should the solvent be below the starting line in chromatogrpahtx


 for "why should the solvent be below the starting line in chromatogrpahtx":

1.
URL: https://chem.libretexts.org/Ancillary_Materials/Laboratory_Experiments/Wet_Lab_Experiments/Organic_Chemistry_Labs/Lab_I/06%3A_Exp_5-_A_and_B_TLC/6.02%3A_Thin_Layer_Chromatography_(TLC)
Title: 6.2: Thin Layer Chromatography (TLC) - Chemistry LibreTexts
Content: <b>The</b> <b>solvent</b> <b>should</b> not touch the spots when the separation first begins, that's <b>why</b> its level should be <b>below</b> <b>the</b> spots by at least 0.5 cm. Cover the container and wait for elution to proceed. By capillary action, the <b>solvent</b> will immediately start rising up the TLC plate.

2.
URL: https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Supplemental_Modules_(Analytical_Chemistry)/Instrumentation_and_Analysis/Chromatography/V._Chromatography/A._Introducing_Chromatography%3A_Thin_Layer_Chromatography
Title: A. Introducing Chromatography: Thin Layer Chromatography
Content: Thin layer chromatography is done exactly as it says - using a thin, uniform layer of silica gel or alumina coated onto a piece of glass, metal or rigid plastic. The silica gel (or the alumina) is the stationary phase. The stationary phase for thin layer chromatography also often contains a substance which fluoresces in UV light - for reasons ...

3.
URL: https://www.chem.ucla.edu/~bacher/General/30BL/tips/TLC1.html
Title: Thin Layer Chromatography - University of California, Los Angeles
Content: <b>The</b> <b>solvent</b> level has to be <b>below</b> <b>the</b> <b>starting</b> <b>line</b> of the TLC, otherwise the spots will dissolve away. The lower edge of the plate is then dipped in a <b>solvent</b>. <b>The</b> <b>solvent</b> (eluent) travels up the matrix by capillarity, moving the components of the samples at various rates because of their different degrees of interaction with the matrix ...

4.
URL: https://chem.libretexts.org/Ancillary_Materials/Demos_Techniques_and_Experiments/General_Lab_Techniques/Thin_Layer_Chromatography
Title: Thin Layer Chromatography - Chemistry LibreTexts
Content: Thin layer chromatography (T LC) is a chromatographic technique used to se parate the components of a mixture using a thin stationary phase supported by an inert backing. It may be performed on the analytical scale as a means of monitoring the progress of a reaction, or on the preparative scale to purify small amounts of a compound.

5.
URL: https://chemistryhall.com/thin-layer-chromatography/
Title: Thin Layer Chromatography: A Complete Guide to TLC - Chemistry Hall
Content: TLC plates are generally made of aluminum coated by the stationary phase, and can be cut with scissors. Sometimes, the supporting material is glass and you will need a glass cutter to do the job. Usually, a thin layer chromatography plate is around 5-7 cm high, and a <b>line</b> is drawn around 0.5-1.0 cm from the bottom.

6.
URL: https://www.chemguide.co.uk/analysis/chromatography/thinlayer.html
Title: THIN LAYER CHROMATOGRAPHY - chemguide
Content: Note: I'm taking a simple view of the way that thin layer chromatography works in terms of adsorption (see <b>below</b>) which <b>should</b> <b>be</b> adequate for students doing courses for 16 - 18 year olds.<b>The</b> reality is more complicated and the explanation will vary depending on what sort of <b>solvent</b> or <b>solvent</b> mixture you are using. Some similar problems are discussed on the page about paper chromatography ...

7.
URL: https://www2.chem.wisc.edu/deptfiles/OrgLab/handouts/CHEM%20344%20TLC%20info.pdf
Title: <span class="result__type">PDF</span> CHEM 344 Thin Layer Chromatography - University of Wisconsin-Madison
Content: 3. Pour approx. 3 mL of <b>solvent</b> into a screw-cap jar, place a piece of filter paper in the jar and wet the paper with the <b>solvent</b> to saturate the atmosphere. Make sure that the <b>solvent</b> is shallow enough that it will be <b>below</b> <b>the</b> spot <b>line</b> on your plate. 4. Place the plate carefully in the chamber (use tongs or tweezers), being careful not to ...

8.
URL: https://ocw.mit.edu/courses/5-301-chemistry-laboratory-techniques-january-iap-2012/a24e004fcf5430a16b2a7eb36ac4df40_MIT5_301IAP12_TLC_Handout.pdf
Title: <span class="result__type">PDF</span> Thin Layer Chromatography (TLC) Guide - MIT OpenCourseWare
Content: Thin Layer Chromatography (TLC) is an extremely useful technique for monitoring reactions. It is also used to determine the proper <b>solvent</b> system for performing separations using column chromatography. TLC uses a stationary phase, usually alumina or silica, that is highly polar (standard) or non-polar (reverse phase), and a mobile phase, some ...

9.
URL: https://community.wvu.edu/~josbour1/Labs/Exp%205%20-%20TLC%20-%20F17.pdf
Title: <span class="result__type">PDF</span> 5. Thin Layer Chromatography - West Virginia University
Content: Make sure the <b>solvent</b> level is not above the origin <b>line</b> containing the spot. If the <b>solvent</b> covers the spot, you will need to start over and prepare a new TLC plate. Cover the chamber with a watch glass or foil. Over a few minutes, the <b>solvent</b> will rise up the plate and (ideally) separate the various components that are present in the mixture.

10.
URL: http://www.mendelset.com/articles/683/thin_layer_chromatography_tlc
Title: Thin Layer Chromatography (TLC) - MendelSet
Content: How TLC works - The basic idea. Thin Layer Chromatography (TLC) is a cheap and quick way of determining how many unique chemicals are in a reaction mixture. For example, let's say you have a reaction with two chemicals (shown <b>below</b>) <b>in</b> a round bottom flask. To run a TLC, you use a pencil (not pen) and mark a <b>line</b> at the bottom of the TLC plate.

11.
URL: https://www.merckmillipore.com/INTL/en/analytics-sample-preparation/learning-center-thin-layer-chromatography/tlc-process/tlc-development/57Wb.qB.8ZAAAAFVf6BDx07b,nav
Title: TLC Development - Merck
Content: <b>In</b> this common TLC development method, the plate is placed in a suitable TLC developing chamber such that the <b>solvent</b> wets the TLC layer <b>below</b> <b>the</b> <b>starting</b> <b>line</b>. Due to capillary forces, the <b>solvent</b> rises up the layer, transporting the sample mixture. Once the <b>solvent</b> front has reached the predetermined height (10-15 cm for TLC and 3-7 cm for ...

12.
URL: https://www.emdmillipore.com/US/en/analytics-sample-preparation/learning-center-thin-layer-chromatography/tlc-process/tlc-tips-tricks/d4Kb.qB.r4MAAAFViSVDx07i,nav
Title: TLC Tips and Tricks - MilliporeSigma
Content: <b>The</b> choice of <b>solvent</b> system is critical in thin-layer chromatography. Follow the guidelines and table <b>below</b> to find the most suitable mobile phase for your separation. To choose the right <b>solvent</b>, start with pure <b>solvents</b> of medium elution strength. Perform spot tests to compare different <b>solvent</b> systems.

13.
URL: https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Organic_Chemistry_Lab_Techniques_(Nichols)/02%3A_Chromatography/2.03%3A_Thin_Layer_Chromatography_(TLC)/2.3E%3A_Step-by-Step_Procedures_for_Thin_Layer_Chromatography
Title: 2.3E: Step-by-Step Procedures for Thin Layer Chromatography
Content: Rinse the spotter with a <b>solvent</b> (e.g. acetone) if going to use it for another sample. Place the sample in the TLC chamber with forceps, cap it, and leave it alone. Remove the plate when the <b>solvent</b> <b>line</b> is \(\sim 0.5 \: \text{cm}\) from the top. Immediately mark the <b>solvent</b> <b>line</b> with a pencil. Visualize if necessary.

14.
URL: https://www.orgchemboulder.com/Technique/Procedures/TLC/TLC.shtml
Title: Thin Layer Chromatography (TLC) - orgchemboulder.com
Content: Thin Layer Chromatography (TLC) TLC is a simple, quick, and inexpensive procedure that gives the chemist a quick answer as to how many components are in a mixture. TLC is also used to support the identity of a compound in a mixture when the R f of a compound is compared with the R f of a known compound (preferably both run on the same TLC plate ...

15.
URL: https://ecampusontario.pressbooks.pub/orgbiochemsupplement/chapter/thin-paper-chromatography/
Title: 29.2 Thin Layer (TLC) and Paper Chromatography (PC)
Content: <b>The</b> <b>solvent</b> level is <b>below</b> that of the sample spot. Figure 29.2f. Setup of TLC (thin layer chromatography) (credit: Chromatography, CC BY-NC 4.0). As the <b>solvent</b> slowly travels up the plate, the different components of the dye mixture travel at different rates and the mixture is separated into different coloured spots.


Assistant: