Analysis of contaminant polycyclic aromatic hydrocarbons in tea products and crude drugs

Abstract

Tea products and crude drugs were analyzed to determine levels of contamination with 15 polycyclic aromatic hydrocarbons (PAHs) using a new online automated method, consisting of in-tube solidphase microextraction (SPME) coupled with high-performance liquid chromatography-fluorescence detection (HPLC-FLD). PAHs were separated within 15 min by HPLC using a Zorbax Eclipse PAH column with a water/acetonitrile gradient elution program as the mobile phase. The optimum in-tube SPME conditions were 20 draw/eject cycles of 40 mL of sample using a CP-Sil 19CB capillary column as an extraction device. Low-and high-molecular weight PAHs were extracted effectively onto the capillary coating from 5% and 30% methanol solutions, respectively. The extracted PAHs were readily desorbed from the capillary by passage of the mobile phase. Good linearity of the calibration curve (r > 0.9972) was obtained in the concentration range of 0.05-2.0 ng mL À1 , and the detection limits (S/N ¼ 3) of PAHs were 0.32-4.63 pg mL À1 . Using the in-tube SPME/HPLC-FLD method, PAHs were detected at ng g À1 levels in the samples without interference peaks. Our results suggest that PAHs contamination in herbal products is widespread, and the proposed method may become a useful tool for monitoring PAH contamination and quality control in herbal products.

Online capillary solid-phase microextraction coupled liquid chromatography-mass spectrometry for analysis of chiral secondary alcohol products in yeast catalyzed stereoselective reduction cell culture

“…This column has been used by researchers for extraction compounds such as steroid hormones [27,34,39,47], ochratoxins [32] and aflatoxins [45], emerging contaminants [33,40] and phthalate esters [40][41][42], and heterocyclic amines [46] that indicates an suitable choice for our application. Since the extraction solvent for SPME was deionized distilled water, a suitable desorption and elution solvent must bear some polar property to avoid producing inhomogeneous phase of the eluent with adsorbed residue water during analytes desorption and analysis.…”

“…Nowadays, the SPME technique has been extensively applied to various samples such as environmental waters [25][26][27][28][29][30][31], wine samples [22,23], nuts and grains [32], tea products and crude drugs [33], human urine [34][35][36][37][38], human saliva [38,39], liquid medicines and intravenous injection solutions [40], and human hair [35]. Recently, in order to increase the detection sensitivity for ultra-trace sample analysis, the SPME coupled liquid chromatography has switched its detector from spectrometers such as ultraviolet (UV) detector [30,37,[40][41][42] and fluorescence (FL) detector [33] to high sensitivity mass spectrometer (MS) [26,29,32,[34][35][36]38,39,[43][44][45] and tandem mass spectrometer (MS/MS) [25,27,28,31,46,47].…”

Application of QuEChERS based method for the determination of pesticides in nutraceutical products (Camellia sinensis) by liquid chromatography coupled to triple quadrupole tandem mass spectrometry

“…Concerning sample treatment, in the case of green tea, QuEChERS (acronym of quick, easy, cheap, effective, rugged and safe) is the extraction procedure most widely used by the revised literature (Chen et al, 2010;Kanrar, Mandal, & Bhattacharyya, 2010;Kittlaus, Schimanke, Kempe, & Speer, 2013;Lozano et al, 2012;Rajski et al, 2013;Zhao, Wang, Jiang, Zhang, & Pan, 2012). Other sample treatments used were solid phase extraction (SPE) (Gupta & Shanker, 2008;Huang et al, 2009;Inoue et al, 2013;Lu et al, 2010;Zhang et al, 2010), and solid phase microextraction (SPME) (Ishizaki, Sito, & Kataoka, 2010).…”

“…Concerning detectors used for pesticide determination and quantification in green tea, triple quadropole tandem mass spectrometry is the most widely used (QqQ-MS/MS) (Chen et al, 2010;Huang et al, 2009;Kanrar et al, 2010;Kittlaus et al, 2013;Lozano et al, 2012;Lu et al, 2010;Rajski et al, 2013;Zhang et al, 2010;Zhao et al, 2012), although classical detectors were also used, like diode array (DAD) (Gupta & Shanker, 2008) or fluorescence (FD) (Inoue et al, 2013;Ishizaki et al, 2010). Bearing in mind that the Commission Decision 2002/657 recommends the use of mass spectrometry (MS) techniques (Council Decision, 2002), QqQ-MS/MS has been implemented for routine analysis.…”

“…Gas chromatography (GC) (Cajka et al, 2012;Lozano et al, 2012;Rajski et al, 2013) and liquid chromatography (LC) (Chen et al, 2010;Gupta & Shanker, 2008;Huang et al, 2009;Inoue et al, 2013;Ishizaki et al, 2010;Kanrar et al, 2010;Kittlaus et al, 2013;Lu et al, 2010;Zhang et al, 2010;Zhao et al, 2012) are commonly used for the separation of pesticides. Although GC amenable pesticides can still be used, LC is replacing GC methodologies bearing in mind that pesticides are often more polar and less volatile.…”