Weigh 0.23 g of 2-hydroxybenzoic acid (salicylic acid) into a test tube. Small Rf values tend to indicate larger, less soluble pigments while the highly soluble pigments have an Rf value near to one. For the unknown powder, we obtained Rf values of 0.52 and 0.76 so we believe that the unknown powder contains Aspirin and Ibuprofen. Trace the TLC plates and associated spots into your laboratory notebook, and note any distinguishing features. So, an aspirin solution is to be run against a polar solvent (mobile phase) when the stationary phase is less polar than the mobile one. . For both of these known drugs, the Rf values acquired were close to my predictions before the experiment. Other names: Benzoic acid, 2-(acetyloxy)-; Salicylic acid acetate; o-Acetoxybenzoic acid; o-Carboxyphenyl acetate; A.S.A. Transcribed image text: TABLE 1: Rf VALUES OF KNOWN ANALGESCS IN ETHYL ACETATE/HEXANE SOLVENT Acetaminophen Aspirin Caffeine Naproxen . 149 O. For both of these known drugs, the Rf values acquired were close to my predictions before the experiment. Rf is retention factor, it is defined as the distance travelled by the compound divided by the distance travelled by the solvent. Just here to remind you to post a comment either by replying to this message or as a separate comment to your post and walk us through your thought process. National Center for Biotechnology Information. Equation 2: Rf= spot distance from origin solvent front distance from origin And for my Rf values I got Rf (reference - salicylic acid and ethyl acetate) = 2.47 5.30 = 0.466 . Between aspirin and acetaminophen, which would travel through the HPLC the slowest and have the . light or iodine vapour. In the example below, the Rf value for substance A is equal to x/a. Discussion: The purpose of the lab was to synthesize aspirin from salicylic acid and acetic anhydride. That being said, aspirin travelled the greatest distance and has the highest Rf value. And also to carefully . It is calculated by dividing the distance moved by the solvent by the distance moved by the spot. This alteration in RF value of these drugs in the presence of surfactant in solvent systems, may be due to variable hydrophobic or hydrophilic interactions with these drugs. It also blocks thromboxane A2 on platelets in an irreversible fashion preventing platelet aggregation. Table 1 - Experiment Values. The Rf value of caffeine was 0.16, while the unknown 1 was 0.15 clearly demonstrating the closeness in numerical values. That being said, aspirin travelled the greatest distance and has the highest Rf value. Then, wipe down your benchtop with a wet paper towel and dry it. Retention factors are useful in comparing the results of one chromatogram to the results of another. The product was analyzed using the melt point, the FeCl3 . Procedure. The Rf value for paracetamol Rf = 3.90/6.1 Rf value = 0.639 = 0.64 RESULTS (b). The Rf value for aspirin is 1.25/1.48 equals 0.84. distance the eluting solvent travels (solvent front), is used to produce a value known as the retention factor that is unique for each compound (when the experimental conditions are carefully selected and controlled). 24 o. Synthesis of Acetylsalicylic Acid (Aspirin) Anna Shahrour Partner Jocelyn Barraza TA Yong Wang Section 05 Introduction Aspirin is the common name for the compound acetylsalicylic acid, widely used as a fever reducer and as a painkiller. . Background. The less polar the sample, the less it binds to the plate and the faster it travels, increasing the Rf value. What is the Rf value for aspirin? Similarly, what is the RF value of aspirin? 1+2.) This is all in relation to a purity test of aspirin compared to salicylic acid. Aspirin Rf. The hardiness of the method is evidenced by the Rf values, which vary by no more than 3% over a four-month period. Acetylsalicylic acid is expected to have a lower Rf value than salicylic acid. Identify the components of the mixture, and identify each of the The Rf value for aspirin is 1.25/1.48 equals 0.84. For fractions 6-10, the R. f. value was 0.63 indicating that the component was aspirin. The Rf values are 0.70 for salicylic acid and diflunisal, 0.67 for aspirin and methyl salicylate, 0.60 for gentisic acid, 0.57 for p-aminosalicyclic acid, and 0.40 for salicyluric acid. Hello. The Rf values indicate how soluble the particular pigment is in the solvent by how high the pigment moves on the paper. When the second TLC showed . Analysis Of Rf Value Of Caffeine. This relationship is shown below in equation 2. 81 TABLE 2: ANALYSIS OF UNKNOWN LIQUID IN ETHYL ACETATE/HEXANE SOLVENT Unknown # Identity of Compound Rf Naproxen Spot 1 Spot 2* Spot 3* Acetaminopnen NAA NIA * Unknown may contain as few as one or as many as three compounds 2. 1uL of aminoacid solution in water (5mg/mL; 3mg Na2CO3 added for Cystine, Phenylalanine and Tyrosine) was applied (about 3mm spot was formed).This means each spot contained 5ug (65 nmols to 25 nmols) of an aminoacid. Place in the water bath and leave for 15 minutes. Fractions 1, 3, 4, and 5 did not show most likely because of poor spotting and should have been re-spotted for better analysis. The melting point of the experimentally synthesized Aspirin product was found to be between 126-129 C. All three samples seem similar which suggests our class samples have the same purity as the manufactured aspirin. There was a misreading of the TLC plates which resulted in a miscalculation of the Rf values. 24 o. IUPAC Standard InChIKey: BSYNRYMUTXBXSQ-UHFFFAOYSA-N Copy CAS Registry Number: 50-78-2 Chemical structure: This structure is also available as a 2d Mol file or as a computed 3d SD file The 3d structure may be viewed using Java or Javascript. Rf values do not have units since it is a ration of distances. TLC was done on a regular silica plate. The melting point of the product ranged from . Rf value = distance travelled by substance divided by the distance travelled by solvent. Furthermore, the retention factors change depending on the conditions (choice of mobile phase, stationary phase, temperature, etc). The NPR includes the admission and discharge dates and the diagnoses at discharge for all hospital stays in Sweden. Unlike other NSAIDs (ibuprofen/naproxen), which bind reversibly to this enzyme, aspirin binding is irreversible. f values for all the spots. Rf = 0.78 (Ethanol-Methanol mixture {1:2}) - a mixture of 1 part . The Rf values are 0.70 for salicylic acid and diflunisal, 0.67 for aspirin and methyl salicylate, 0.60 for gentisic acid, 0.57 for p-aminosalicyclic acid, and 0.40 for salicyluric acid. Unknown 2 was determined to have aspirin, acetaminophen and caffeine present due to the closeness of Rf value of the known components compared to the Rf values of . Would it be possible to make some vague estimations based on aspirins polarity and solubility? The International Classification of Diseases 10th Revision (I63 and I64) codes were used for recording cerebral infarction. Rf value = distance travelled by substance divided by the distance travelled by solvent. Calculate the R. f values for each spot. 81 TABLE 2: ANALYSIS OF UNKNOWN LIQUID IN ETHYL ACETATE/HEXANE SOLVENT Unknown # Identity of Compound Rf Naproxen Spot 1 Spot 2* Spot 3* Acetaminopnen NAA NIA * Unknown may contain as few as one or as many as three compounds 2. The more polar the sample the smaller the Rf values because the sample will bind tightly to the plate. That is incredibly specific. d. SUMMARY AND DISCUSSION: After the slides were placed into the jar containing TLC, the chromatogram did not develop for Ibuprofen or Aspirin. Theoretical Yield of Aspirin (g)= 5.4 Mass of Crude Aspirin (g)= 2.6 % yield of Crude Aspirin= 48 % Mass of Recrystallized Aspirin (g)= 1.7 % yield of Recrystallized Aspirin= 31% 1.Using your yield of recrystallized product, determine the mass ofsalicyclic acid needed make 100 tablets of extra strength aspirinif each tablet has 500 mg of . Background. Click to see full answer. Anacin's Rf values clearly correspond to those of caffeine and aspirin. (l), An. The Rf value for paracetamol Rf = 3.90/6.1 Rf value = 0.639 = 0.64 RESULTS (b). values and literature values do not always agree. In general, low polarity compounds have higher R f values than higher polarity compounds. The hardiness of the method is evidenced by the Rf values, which vary by no more than 3% over a four-month period. Finally, the Rf values of unknown samples were compared with Rf values of the standard samples. Linearity ranges, mean recoveries and relative standard deviations in calibration graphs of the proposed method were . Below is a group TLC of all 20 aminoacids plus some other related compounds. Mechanism of Action. To confirm the results for the known drugs, we can find the literature value of the Rf. 7) whereas the RF value of paracetamol (RF 0.62) decreases. Rf Values The Rf value for a substance is the distance that substance travels compared to the distance the solvent travels. What is the RF value for aspirin? Does anybody know the Rf value of aspirin in solvent 45:50:5 mixture of hexane, ethyl acetate and acetic acid? In the example below, the Rf value for substance A is equal to x/a. The results gathered showed that compound A had two spots, lower spot had an rf value of 0.48 and upper spot had an rf value of 0.77, this shows that compound A contained both paracetamol which has an rf value of 0.48 and caffeine which has an rf value of 0.77. Because aspirin is polar (I believe would be considered polar because it dissolves in water despite some other sources saying that it is actually non-polar) and the silica in the TLC plates are also polar, aspirin would not be able to travel very far because it would interact with the silica. Efficient separation of the components of mixture (III) was attained using ethyl acetate as mobile phase with Rf values of 0.12, 0.62 and 0.42 for chlorphenoxamine hydrochloride, 8-chlorotheophylline and caffeine, respectively. Transcribed image text: TABLE 1: Rf VALUES OF KNOWN ANALGESCS IN ETHYL ACETATE/HEXANE SOLVENT Acetaminophen Aspirin Caffeine Naproxen . Aspirin is a cyclooxygenase-1 (COX-1) inhibitor. Rf Values 1 2 3 solvent front baseline s s & p p s starting point p product. Rf (retention or retardation factor): is a measure of the distance travelled by the compound spot in relation to the distance travelled by the eluent. In order to determine whether an unknown compound is identical to a compound of known structure, it is necessary to run the two samples side by side on the same TLC plate, preferably at the same concentration. Substances: Aspirin Caffeine Acetaminophen IbuprofenExcedrin Anacin Rf Values: 0.45 0.08 0.24 0.60 0.09 0.10 0.26 0.46 0.39 Aspirin Caffeine Ibuprofen Acetaminophen Exc. Retardation Factor (Rf) Experimental data show that aspirin is the least polar among the three, followed by acetaminophen, then caffeine, the most polar. Finally, the Rf values of unknown samples were compared with Rf values of the standard samples. First, an average molecular weight of 1.7 x 10 2 g/mol was derived from titrations (table 2.2). Thin Layer Chromatography of aminoacids and short peptides. Thin-Layer Chromatography. This will leave aspirin at a specific height giving its Rf value between 0 and 1. PubChem . The retention factor (rf) of a particular material is the ratio of the distance the spot moved above the origin to the distance the solvent front moved above the origin. It seems as if the acetaminophen and ibuprofen readings were off. If a permanent record is needed, take a photo as the spots of colour will fade. Aspirin | C9H8O4 | CID 2244 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity information, supplier lists, and more. Rf Values Name Distance from Base to Center of Spot (cm) Distance from Base to Sovlent Front (cm) = Rf Value acetaminophen 4.0 5.5 = .73 aspirin 4.7 5.5 = .85 caffeine 2.4 5.5 = .44 salicylamide 4.6 5.5 = .84 Anacin 2.6 5.8 = .45 Bufferin Read More Essay about Isolation of Components of Bc Powder 1655 Words | 7 Pages ! TLC uses the different affinities a compound has for the mobile and stationary phases to achieve separation of mixtures of organic compounds. I've been trawling the web but I can't find anything on the Rf values of aspirin in 2:1 Hexane: Ethyl Acetate and also in 65:30:5 Hexane: Ethyl Acetate: Acetic Acid. as explained above. I've been trawling the web but I can't find anything on the Rf values of aspirin in 2:1 Hexane: Ethyl Acetate and also in 65:30:5 Hexane: Ethyl Acetate: Acetic Acid. 100% hexane. (r) Created Date: 20070122133001Z . It is calculated by dividing the distance moved by the solvent by the distance moved by the spot. Therefore, the Rf value was calculated base on the formula below. -All components will have higher Rf Values. Rf stands for retardation factor. "Aspirin Synthesis - Alternate (Non-Mi ro a e) Pro edure" pg. Therefore, the Rf value was calculated base on the formula below. value of 0.50, indicating that the component was aspirin. middle Rf values clearly correspond to those of caffeine and acetaminophen, respectively. Would it be possible to make some vague estimations based on aspirins polarity and solubility? Aspirin is a relatively simple molecule containing an ethylated phenol group and a carboxylic acid group. Two pigments with the same Rf value are likely to be identical molecules. Thin layer chromatography (TLC) is used routinely in the laboratory to both monitor reactions and analyse the purity of samples. Rf values do not have units since it is a ration of distances. If the solvent system was changed, which solvent system would result in a DECREASE in the Rf value of aspirin (solvent structures shown beside the TLC plate)? This experiment uses TLC to analyse standards of caffeine and three analgesics, acetylsalicylic acid (aspirin), acetaminophen (paracetamol) and ibuprofen. National Library of Medicine. The Rf values are 0.70 for salicylic acid and diflunisal, 0.67 for aspirin and methyl salicylate, 0.60 for gentisic acid, 0.57 for p-aminosalicyclic acid, and 0.40 for salicyluric acid. Thus, it is necessary to further analyze it with mass spectrometers, etc. Request PDF | HPTLC Separation and Quantitative Analysis of Aspirin, Salicylic Acid, and Sulfosalicylic Acid | A new, simple, accurate, and precise HPTLC method has been established for separation . There was no spot for fraction 11 indicating that the tube contained . Retention factors range between zero and one. This value, compared with the molecular weight of commercial aspirin, C 9 H 8 O 4, will demonstrate the difference in purity.The molecular weight of commercial aspirin is 180 . Table 2 - TLC Values. Again, if you look in the literature for TLC results of aspirin and salicylic acid, you will find varying Rf values, so one shouldn't be overly concerned about it. TLC is a type of adsorption chromatography, and the most common substrates used for the stationary phases in the lab, are silica (SiO 2) and alumina (Al 2 O 3).It is recommended that you read the page on adsorption chromatography before doing this experiment. Solid aspirin waste can go in the trash can. If the conditions in which . National Institutes of Health. Half-fill a 50 cm 3 beaker with deionised water, and heat to 70-80 C. [20] (CI 7.3) Nuclear Magnetic Resonance (n.m.r . Thin-layer chromatography (TLC) is an important technique in organic chemistry. This temperature range of initial to final melting point has a small and sharp temperature range of only 3C, which is within the acceptable limits of the 128-137C1 literature value for Aspirin (Acetylsalicylic Acid/2-acetoxybenzoic acid), if located slightly toward the beginning of the . ; Separations and spot shapes are . Rf = 0.78 (Ethanol-Methanol mixture {1:2}) - a mixture of 1 part . Since the chromatogram did not develop, there was no way to observe the distance the dot or the solvent traveled, therefore not supplying an Rf value. Add 25 drops of ethanoic anhydride followed by one drop of 85% phosphoric acid. Hence, it is theoretically possible that a compound with Rf value of 0.429 that is not aspirin is mixed with it. TLC is a type of adsorption chromatography, and the most common substrates used for the stationary phases in the lab, are silica (SiO 2) and alumina (Al 2 O 3).It is recommended that you read the page on adsorption chromatography before doing this experiment. Laboratory Manual for Organic Chemistry. Thin Layer Chromatography Report List the calculated Rf values for aspirin, acetaminophen, ibuprofen, and caffeine in your final eluent system. fof the presence of impure aspirin in the product, but indistinctly hinted at the remaining presence of unacetylated salicylic acid, enabling the conclusion of an uncompleted reaction process. Similar Rf values will not necessarily mean that the two components are the same molecule. 149 O. Analyze Polarity vs Rf Value. Compound B had an rf value of 0.77 which is . These values will vary with temperature, humidity, and . Cinnamedrine is actually a mixture of 3 parts aspirin to 1 part caffeine, and is in both Anacin and Vanquish c) Cinnamedrine is . Because mixture solvents are often applied Rf values are usually written as the following examples: Rf = 0.66 (60% Ethanol) - if % is given it is assumed that the mixture is in water hence 60% ethanol 40% water. What are the units for Rf values? In your experiment you will make aspirin from an acid called . The Rf values are 0.70 for salicylic acid and diflunisal, 0.67 for aspirin and methyl salicylate, 0.60 for gentisic acid, 0.57 for p-aminosalicyclic acid, and 0.40 for salicyluric acid. TLC can also be used to identify compounds by comparison with known samples, check the relative . For the unknown powder, we obtained Rf values of 0.52 and 0.76 so we believe that the unknown powder contains Aspirin and Ibuprofen. Material / Distance Traveled / Rf Value Product / 5.65 cm / 0.85 Anacin / 1.87 & 5.70 cm / 0.28 & 0.86 Caffeine / 1.95 cm / 0.29. To confirm the results for the known drugs, we can find the literature value of the Rf. distinguishing compounds with similar Rf values. Detection limits of 1 ppm or less for all the analytes compared favorably to limits of more than 20 ppm for Trinder's test. 3.4 Hazardous Waste and Clean-up 3.4.1 Hazardous Waste Pour the used TLC solvent into the waste container in the hood at the front of the lab. The NPR has been validated, and a diagnosis of stroke had a positive predictive value of approximately 90% . [20] (CI 7.3) Nuclear Magnetic Resonance (n.m.r . The Rf value for the Ibuprofen was ~0.56, ~0.47 for acetaminophen, ~0.16 for caffeine, and ~2.7 for aspirin. Similar Rf values will not necessarily mean that the two components are the same molecule. A desirable Rf value lies between 0.3 and 0.7, since it is likely that other compounds present in the mixture will be visible on the TLC plate when the Rf is in this range. For ibuprofen, the Rf value is 1.32/1.48 equals 0.89, and for acetaminophen, the Rf value is 1.07/1.48 equals 0.72. The hardiness of the method is evidenced by the Rf values, which vary by no more than 3% over a four-month period. Caffeine: 23.5mL/65mL= 0.36 Ibuprofen: 54mL/65mL= 0.83 Aspirin 1: 42mL/65mL= 0.65 Aspirin 2: 46mL/65mL=0.71 Aspirin 3: 54mL/65mL=0.83 Acetaminophen: 42mL/65mL = 0.65 List the calculated. Rf of Caffeine 0 cm / 2 cm =. For it to be a valid comparison, the TLC plates must be run under the exact same conditions for temperature, stationary phase, and mobile phase. Thin layer chromatography (TLC) is used routinely in the laboratory to both monitor reactions and analyse the purity of samples. For ibuprofen, the Rf value is 1.32/1.48 equals 0.89, and for acetaminophen, the Rf value is 1.07/1.48 equals 0.72. Rf Values The Rf value for a substance is the distance that substance travels compared to the distance the solvent travels. It is a modifier of the enzymatic activity of cyclooxygenase-2 (COX-2). The Rf values are always different for different stationary and mobile phases used. This is all in relation to a purity test of aspirin compared to salicylic acid. Because mixture solvents are often applied Rf values are usually written as the following examples: Rf = 0.66 (60% Ethanol) - if % is given it is assumed that the mixture is in water hence 60% ethanol 40% water. 3.4.2 Clean-up Dry your glassware and return it to your station. There are several things to be taken away from the collected data in regards to the purity of the synthesized aspirin sample. Different analytes can be distinguished by their Rf values as well as by their appearance under UV light or after treatment with other visualising reagents. RF value of aspirin (RF 0.32) and ascorbic acid (RF 0.14) (Fig.