Fluorescence Polarization Immunoassays for the Quantification of Caffeine in Beverages

Abstract

Homogeneous fluorescence polarization immunoassays (FPIAs) were developed and compared for the determination of caffeine in beverages and cosmetics. FPIAs were performed in cuvettes in a spectrometer for kinetic FP measurements as well as in microtiter plates (MTPs) on a multimode reader. Both FPIAs showed measurement ranges in the μg/L range and were performed within 2 and 20 min, respectively. For the application on real samples, high coefficients of variations (CVs) were observed for the performance in MTPs; the CVs for FPIAs in cuvettes were below 4%. The correlations between this method and reference methods were satisfying. The sensitivity was sufficient for all tested samples including decaffeinated coffee without preconcentration steps. The FPIA in cuvettes allows a fast, precise, and automated quantitative analysis of caffeine in consumer products, whereas FPIAs in MTPs are suitable for semiquantitative high-throughput screenings. Moreover, specific quality criteria for heterogeneous assays were applied to homogeneous immunoassays.

Correlation between caffeine contents of green coffee beans and altitudes of the coffee plants grown in southwest Ethiopia

“…Many analytical methods have been developed for the quality control of products containing caffeine: liquid chromatography-particle beam/electron ionization mass spectrophotometry [11], liquid chromatography-tandem mass spectrometry [12], near infrared spectroscopy [13], near infra-red reflectance spectroscopy [14], gas chromatography [15] and fluorescence polarization immunoassays [16].…”

Development of new analytical methods for the determination of caffeine content in aqueous solution of green coffee beans

“…Many analytical methods have been developed for the determination of caffeine in coffee beans and products containing caffeine including electroanalytical [7, 8]; chromatographic [4, 9, 10] techniques including gas chromatography [11–13], high performance liquid chromatography (HPLC) [4, 10, 14, 15], liquid chromatography-particle beam/electron ionization mass spectrophotometry [16], liquid chromatography-tandem mass spectrometry [17], and spectroscopic techniques [1, 4, 18–22] including nuclear magnetic resonance spectroscopy [23], near infrared spectroscopy [24, 25], near infra-red reflectance spectroscopy [26], and UV–Vis spectroscopy [1, 20, 27, 28], and fluorescence polarization immunoassays [29]. HPLC is the method of choice by many researchers in determining the caffeine contents of beverages, tea leaves and coffee beans.…”

Rapid and homologous immunoassay for the detection of herbicide propisochlor in water

“…However, the intensive use of herbicides has resulted in serious pollution of agricultural products, soil resources, especially water resources, which pollute the whole ecological system, and possibly leads to a serious threat to the safety of the water resources (Brender & Weyer, 2016;Cruzeiro, Rocha, Pardal, & Rocha, 2016;Lei et al, 2011). In recent years, more and more attention has been paid to herbicide residue in water samples worldwide (Feng, Yu, Liu, Liu, & Sun, 2015;Lu, Peterson, Gooding, & Lee, 2012;Oberleitner et al, 2014;Wu et al, 2013;Zhang et al, 2011). These residual herbicides in water samples also presented a high risk to human health (Barbosa, Solano Mde, & Umbuzeiro Gde, 2015;Benito-Peña, MorenoBondi, Orellana, Maquieira, & van Amerongen, 2005;Kolosova et al, 2017;Sekhotha, Monyeki, & Sibuyi, 2016;Zhang et al, 2011).…”