Isolation of caffeine from carbonated beverages

 Isolation of caffeine from carbonated beverages

Author Name: Ali Khan (Analytical Chemistry)

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Abstract

The goal of this study was to isolate a naturally occurring alkaloid from carbonated beverages. Caffeine is a common component included in various energy drinks. It's used to increase flavour and make the drinks more addicting. Caffeine is a white crystalline xanthenes alkaloid with a bitter taste that works as a psychoactive stimulant and a moderate diuretic. Caffeine (1, 3, 7-trimethylxanthine) and belongs to the Methylxanthine alkaloids family. In the current work Liquid-liquid extraction technique were used. Chloroform was employed as an extracting solvent. Caffeine was recrystallized from 95 percent ethanol of 6 mL/gram. It is concluded increase the concentration of caffeine effect various drugs like Benzodiazepines, Paracetamol, and Aspirin. For caffeine isolation, the most commonly accessible soft drinks are employed. The maximum amount of caffeine was isolated from Sting and low concentration low amount 7up.

1.         Introduction

 Caffeine (1, 3, 7-trimethylxanthine) belongs to the Methylxanthine alkaloids family. Chemical formula of caffeine is C₈H₁₀N₄O₂ and 1, 3, 5- trimethylxanthine is the systematic name [1].

Caffeine is available in the form of odorless, fleecy masses and white, gleaming powder needles. Caffeine has a molecular weight (M.W) of 194.19 grams and a melting point of 236 °C. Caffeine has a pH of 6.9 in a 1% solution, a specific gravity of 1.2, a volatility of 0.5 percent, and a vapour pressure of 760 mm of Hg at 178°C at atmospheric pressure. Caffeine vapour density is 6.7 and its solubility in water is 2.17 percent. Caffeine's widespread prevalence in various plants contributes to caffeine's long-standing acceptance. Coffee beans, tea leaves, and cocoa beans/leaves all contain caffeine. Caffeine is found in tea, chocolate, cocoa, and different soft drinks, and it is consumed by people. Caffeine content varies by product; Guarana (4-7%) has the most, followed by tea leaves 3.5%, coffee beans 1.1-2.2%, cola nuts 1.5%, and cocoa beans 1.1-2.2%. Caffeine's stimulant properties have long been known. It acts as a diuretic and boosts brain activity by stimulating the heart and central nervous system. Caffeine, on the other hand, can trigger a variety of unpleasant symptoms in humans, including tachycardia, tremor, seizures, gastrointestinal problems, and even death. Caffeine levels in foods and beverages must therefore be monitored for typical human activity. [2]. 

Caffeine has received more attention in recent decades as a result of its increased use and physiological stimulatory effects. The amount of caffeine in human saliva peaks roughly 40 minutes after caffeine consumption, indicating the extent of absorption. The cardiovascular, respiratory, gastrointestinal, central nervous, and renal systems have all been shown to have different physiological impacts. Caffeine causes a little increase in blood pressure. Additionally, effect of caffeine’s diuretic is widely known [2, 3]. Caffeine metabolism takes place in the liver, where three primary demethylation processes are carried out by cytochrome P450122 (CYP1A2) (Carrillo and Benitez). The CYP1A2 enzyme is responsible for more than 95 percent of caffeine metabolism, ranging from the removal of the methyl (-CH3) group from carbon #3 through demethylation, a frequent metabolism step (carriti & Benitez, 200). This would appear to suggest increased caffeine metabolism in devoted caffeine users due to up-regulation of the CYP1A2 enzyme, an indicator of caffeine tolerance; It also means that non-caffeine users are more susceptible to high-caffeine medications because the drugs do not clear as quickly. 

Caffeine levels in coffee, carbonated beverages, tea, and chocolate goods have all been studied. The caffeine concentrations of 24 fountains, 20 different prepackaged of a national brand carbonated beverages, and 16 different prepackaged of a private label store brand carbonated beverages were imposed 10 years ago on a broad scale; the store-brand beverages were limited to goods from four stores. Because the caffeine content of carbonated beverages isn't listed on the label, also the consumers are in dark about how much caffeine is in them [4]. Different governmental authorities regulate the amount of caffeine that can be found in carbonated beverages. Caffeine content in carbonated beverages is limited to 0.02 percent by the U.S Food [5] and in the drug Administration. As a result, the maximum quantity of caffeine is allowed in a 355 mL (12 oz) soft drink can is 72 mg. Similarly, Canada has set a caffeine restriction of 200 ppm (about 71 mg/12 oz) for cola-type beverages (Department of the Justice 2007). The maximum amount of caffeine allowed in cola-type beverages is 145 mg/kg (approximately 51 mg/12 oz). 

Different testing procedures are used in Australia to determine the caffeine level of carbonated beverages and foods. UV–visible spectrophotometry, high-performance liquid chromatography (HPLC), gas chromatography (GC), thin-layer chromatography/mass spectrometry (TLC/MS), Fourier transforms infrared spectrometry (FTIR), ion chromatography, and capillary electrophoresis (CE) are some of the techniques used [3, 6]. In the current thesis naturally occurring alkaloid (caffeine) were illustrated.

2.         Apparatus and chemicals

Chloroform (chemical formula, CHCl3), de-ionized water, stirrer, spirit, tripod stand, lamp, separating funnel and carbonated beverages (Red bull, Pepsi, Coca cola, etc.).

                    i.            Carbonated beverages Samples

Various samples were collected from carbonated beverages from the local market Peshawar. The sample contains Coca cola, 7up, Diet Sunkist, Mountain dew, Pepsi cola and Red bull.

                  ii.            Procedure first

200 mL were taken in 250 mL of titration flask and added 200mL of chloroform to it and shaken the mixture for 25 minutes as shown in Figure. 2. After that it was transfer to separating funnel, as a result two layers were formed. First the upper layer was aqueous and the lower contain caffeine it’s due to grater the density of caffeine than water. The chloroform containing layer was  added to 50 mL flask  and then the organic layer (chloroform layer) was transferred to a weighted, 25 mL flask and on the steam bath, the mixture was left to evaporated ethanol and dry. Caffeine solid residue was recrystallized from 95 percent ethanol at a rate of 5 mL/gram (5 mL per gram). In this diagram, the molecular structure of a caffeine crystal is shown (Fig. 1).

                iii.            Procedure second

400 mL were taken in 500 mL of titration flask and added 400mL of chloroform to it and shaken the mixture for 25 minutes as shown in Figure. 2. after that it was transfer to separating funnel, as a result two layers was formed. First the upper layer was aqueous and the lower contain caffeine it’s due to grater the density of caffeine than water. The chloroform containing layer was added to 100 mL flask  and then the organic layer (chloroform layer) was transferred to a weighted, 25 mL flask and on the steam bath, the mixture was left to evaporated ethanol and dry. Caffeine solid residue was recrystallized from 95 percent ethanol at a rate of 5 mL/gram (5 mL per gram). [7].

2. Results and Discussion

                    i.            Physical Characterization

A. Liquid-Liquid extraction proved to be a very efficient and straight forward method. In the table below, the total amount of caffeine initially contained in the various samples, as well as its melting point, boiling point, and percent recovery, is listed.

Table 1. Caffeine amount determined in 200 mL of various carbonated beverages

S. No.	Sample	Caffeine (mg)
01	7up	0.2
02	Coca cola	70
03	Sting	130
04	Red bull	122
05	Mountain dew	30
06	Pepsi cola	71

 Table 2. Caffeine amount determined in 400 mL of various carbonated beverages.

S. No.	Sample	Caffeine (mg)
01	7up	0.5
02	Coca cola	133
03	Sting	259
04	Red bull	241
05	Mountain dew	54
06	Pepsi cola	130

 

                  ii.            Spectrophotometer

A Spectrophotometer is a sensitive tool for detecting and measuring caffeine. The UV adsorption of caffeine give two absorption bands peaking at 205 and 273 nm. Caffeine quantity is often evaluated by measuring absorbance at 275 nm. Soft drinks are made up of a wide range of ingredients, many of which absorb UV radiation at 275 nm [8]. As a result, direct measurement of caffeine absorbance in soft drinks is not practicable; instead, the caffeine must be separated from other components before the absorbance test can be made [9] Despite the fact that the Spectrophotometer is a quick and easy procedure, due to spectrum overlap, it is not possible to quantify caffeine directly in coffee beans using traditional UV absorption measurements [10]. Because UV-Visible spectrophotometer is the most extensively used qualitative as well as quantitative determination and separation method, we chose this approach for the determination of caffeine. This approach is very popular it is due to it is non-destructive and may be used on thermally liable substances, unlike gas chromatography. It very susceptible technique because it uses a variety of detecting methods [11].

3.         Conclusion

The liquid-liquid extraction method was found to be easy, precise, and yielded acceptable findings for determining caffeine in beverages. The maximum amount of caffeine was found in sting while low concentration was found in 7up. The caffeine amount present in Coca cola is 0.2 mg, Sting 70/200 mg/mL, Red bull 122 mg/200 mL, Mountain dew 30 mg/200 mL, Red bull 122 mg/200 mL and Pepsi cola 71 mg/200 mL

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