Effective Extraction Method for Determination of Neonicotinoid Residues in Tea

Abstract

Sample preparation using an absorbent for removal of polyphenols and a solid-phase extraction (SPE) cartridge for cleanup followed by high-performance liquid chromatography (HPLC) has been investigated for the simultaneous determination of eight neonicotinoid insecticides (dinotefuran, nitenpyram, thiamethoxam, imidacloprid, clothianidin, imidaclothiz, acetamiprid, and thiacloprid). After tea samples were soaked with water and extracted with acetonitrile, sample extracts were treated with an appropriate amount of polyvinylpolypyrrolidone (PVPP) to effectively remove polyphenols. The treated extract was cleaned up with a Carb-PSA cartridge. Neonicotinoid insecticides were eluted with acetonitrile from the cartridge and dried. The extract was redissolved with methanol/water (1:9, v/v) and analyzed by conventional HPLC coupled with an ultraviolet detector. The recoveries of eight neonicotinoid insecticides in tea samples were 71.4-106.6% at 0.1-1.0 mg kg(-1) spiked levels. Relative standard deviations were <10% for all of the recovery tests. The established method was simple, effective, and accurate and could be used for monitoring neonicotinoid insecticides in tea.

Novel use of PVPP in a modified QuEChERS extraction method for UPLC-MS/MS analysis of neonicotinoid insecticides in tea matrices

“…In this paper, these absorbents were tested in combination with the inexpensive and excellent absorbent PVPP, which has been used to eliminate polyphenols from tea samples. 3 In order to save the more expensive absorbents PSA and GCB, different amounts of PVPP were rst added to eliminate polyphenols, which cause the main disturbance in the tea extract. Spiked tea samples (0.05 mg kg À1 ) were soaked in water and extracted with ACN.…”

“…The LOQs were quite satisfactory when compared to the regulatory limits of daily exposure in tea. 3 Method accuracy and recovery were evaluated by the addition of standard solutions in blank (green, black and oolong) tea samples. Six aliquots of the tea matrix were spiked with target compounds at three concentration levels: 0.01, 0.05 and 0.5 mg kg À1 .…”

Quality assessment of Chrysanthemum indicum Flower by simultaneous quantification of six major ingredients using a single reference standard combined with HPLC fingerprint analysis

“…As shown in Fig.1 B, a good separation and reproducible chromatogram was achieved and 16 peaks were marked as the common peaks (from peak 1 to peak 16) in the chromatograms of the 33 raw herbs. Nine peaks (1,2,3,4,7,10,12,13,16) in the HPLC fingerprint profile were identified by comparing the UV spectra and retention time with the reference compounds. Peak 16 (linarin), the most important active constituents of CIF (China Pharmacopoeia Committee 2010), was chosen to calculate the relative retention time (RRT) and relative peak area (RPA) of all the other peaks.…”

“…However, the limited availability of various chemical standard substances for quantitative analysis is a major hurdle [11]. On assessing the alternative measures available for the practical comprehensive determination of NDSs, the single standard of determination multiple components (SSDMC) method is worth considering [12,13].Through the above analysis, it is necessary to perform the method based on SSDMC method and fingerprint analysis in routine quality control of CIF. In the process, techniques such as HPLC [14], gas chromatography (GC) [15], high performance capillary electrophoresis (HPCE) [16], gas chromatography-mass spectrometry (GC-MS) [17] and liquid chromatography-mass spectrometry (LC-MS)…”

Multi-residue Method for Determination of Selected Neonicotinoid Insecticides in Traditional Chinese Medicine Using Modified Dispersive Solid-phase Extraction Combined with Ultra-performance Liquid Chromatography Tandem Mass Spectrometry

“…Different mobile phases, including methanol-water, acetonitrile-water, methanol-water with 0.1% formic acid and methanol-water with 0.01% formic acid, were investigated based on previous studies. [17][18][19][20] It was found that acetonitrile could provide better ionization conditions than methanol. Nevertheless, all of the peak shapes of compounds became abnormal with peak broadening when acetonitrile was used as an organic solvent.…”