Determination of Pharmaceuticals and Drugs in Consumer Goods

Tatyana Kimbrough1,2

, Gabriele Sabbioni1,3

, Jiafan Wang1,3

1Emerging Scholars Environmental Health Sciences Academy, 2Lake Area New Tech Early College High School,

3Department of Global Environmental Health Sciences, Tulane University School of Public Health and Tropical Medicine

Results and Discussion

Acknowledgements I would like to thank Sena and Dr. Wickliffe for helping me construct my poster. I also would like to thank my science teacher, Mr. Guthrie, for nominating me for the program. I Thank my family and friends for moral support. This work was supported by the Gulf Region Health Outreach Program (GRHOP) which is funded from the Deepwater Horizon Medical Benefits Class Action Settlement approved by The U.S. District Court in New Orleans on January 11,2013.

Abstract Pharmaceuticals are important for the cure of humans. Consumer drugs

such as coffee and alcohol have been part of human diet for centuries. Pharmaceuticals and consumer drugs are found ubiquitous in the environment: drinking water, wastewater, and ground water, etc. In order to reduce the potential toxicity and ecotoxicity of this group of chemicals, reliable analytical methods are required to determine the fate of pharmaceuticals.

This project is the first step in developing the methods to determine the concentration of pharmaceuticals present in the environment. Two chromatographic methods were used, Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC). Caffeine, acetaminophen and aspirin were the target compounds in this study.

All the target compounds can be qualified by both methods but only be quantified by HPLC method. The extraction efficiency in the HPLC method for acetaminophen ranges from 96-99% and 81-93% for caffeine.

Introduction Pharmaceuticals and drugs present in the environment are critical to the well being of all living organisms. Many pharmaceuticals are washed down drains and are disposed into the environment. Residential, commercial, and agricultural pharmaceuticals have two types of disposal they go through to get into the environment, direct disposal and excretion.

It is important to know how much of these pharmaceuticals are present in the environment and how they affect living organisms.

For the present project we developed methods to quantify caffeine, acetaminophen, and aspirin present in consumer goods.

Extraction Efficiency Range

Acetaminophen 96-99%

Caffeine 81-93%

Compound Rf Value

Aspirin 0.79

Caffeine 0.34

Acetaminophen 0.66

Methods and Materials

Materials

• All the solvents and standard compounds including caffeine, acetaminophen, and aspirin are purchased from Fisher Scientific. • SilG/UV254 TLC plate was used as the stationary phase. • Commercial products are used as the unknown samples, which include

Ripit energy drink (S1), Red Bull (S2), Coffee (S3), Iced tea bags (S4), Bayer (S5), Tylenol (S6), Excedrin (S7), and Ibuprophen (S8).

Methods

TLC • Ethyl acetate was used as mobile phase in TLC experiment and methanol was the solvent to dissolve the

compounds.

• Following procedures were used to prepare the samples: o Liquid samples (S1 & S2) were directly used to spot on the TLC plate. o Solid samples (S3 - S8) were crushed and dissolved in methanol (10 mL). Mixtures were centrifuged

@3500 rpm for 15 min after sonication. An aliquot of the supernatants were spotted on the TLC plate using a glass capillary.

o Each TLC plate contains three individual standards for comparison purpose. o Before the solvent front run out of the plate, the experiment was stopped and the reference line was

marked for Rf value determination. o TLC plates were dried and analyzed under UV light @254nm.

HPLC • Methanol(39.25%):Water(59.25%):Acetic Acid(1.5%) was used as the mobile phase for HPLC

determination and solvent to dilute the extracts.

• The following procedures were used to prepare the samples:

o Pills/Tea bags/ coffee blends Mesh 0.01 gram of pill/tea leaves/coffee blends weighed in Falcon tube. Add methanol to dissolve the sample and extract the target compound. Sonicate the suspension or mixture for 15 min and centrifugate the mixture @3500 rpm for 5 min. Dilute the supernatant for HPLC determination.

o Energy drinks Add methanol to dissolve an aliquot of the energy drink in a Falcon tube. Dilute extracts for HPLC determination.

• HPLC Determination o Instrument: Aglient 1100 series o Flow rate: 0.8 mL / min o Detector: UV @ 275nm o Injection: 20 uL

Figure 2. Commercial samples used in this study.

Figure 3. TLC Chamber with the process ongoing. Figure 4. HPLC instrument for analysis.

Table 1. Rf values of standards for TLC analysis.

Table 2. Extraction efficiency range for acetaminophen and caffeine using HPLC method.

TLC

• Rf numbers for all three standards were in the range of 0.1-0.9 (Table 1). • All eight commercial samples were determined and target compounds were shown on the TLC plate. • The developed method is efficient to determine the target pharmaceuticals in this study at a high concentration.

HPLC

• Method developed for HPLC determination was applied for acetaminophen and caffeine only in this study. • Extraction efficiency was determined using commercial samples containing target compounds, which were all above 80% and reproducible (Table 2). • Caffeine concentration was determined in both caffeinated and decaffeinated tea and coffee. Results (Figure 8) show a significant difference between the caffeinated and decaffeinated products.

Conclusion The target compounds can be identified with both methods (TLC and HPLC), but only

quantified with the HPLC method. The extraction efficiency in the HPLC method for acetaminophen ranges from 96-99% and 81-93% for caffeine. The developed methods are reproducible and applicable for environmental samples analysis.

Figure 5. TLC plates with all the results of commercial samples.

Figure 1. Direct disposal and excretion of pharmaceuticals. [Christian G. Daughton, Ph.D., Environmental Protection Agency, Las Vegas, Nevada 89119 www.dtsc.ca.gov/AssessingRisk/PPCP/upload/01_]

Figure 7. Drug extraction from consumer products. Figure 6. HPLC chromatogram for acetaminophen and caffeine.

Figure 8. Caffeine determination of tea and coffee.