Determination of Pyrethroids in Tea Brew by GC-MS Combined with SPME with Multiwalled Carbon Nanotube Coated Fiber

Abstract

A new method has been developed to simultaneously determine 7 pyrethroid residues in tea brew using gas chromatography-mass spectrometry (GC-MS) combined with solid phase microextraction (SPME) with multiwalled carbon nanotubes (MWCNTs) coated fiber. The MWCNTs coated fiber of SPME was homemade by using stainless steel wire as coating carrier and polyacrylonitrile (PAN) solution as adhesive glue. Under the optimized conditions, a good linearity was shown for bifenthrin, fenpropathrin, permethrin, and cyfluthrin in 1–50 ng mL−1 and for cypermethrin, fenvalerate, and deltamethrin in 5–50 ng mL−1. The correlation coefficients were in the range of 0.9948–0.9999. The average recoveries of 7 pyrethroids were 94.2%–107.3% and the relative standard deviations (RSDs) were less than 15%. The detection limit of the method ranged from 0.12 to 1.65 ng mL−1. The tea brew samples made from some commercial tea samples were analyzed. Among them, bifenthrin, fenpropathrin, and permethrin were found. The results show that the method is rapid and sensitive and requires low organic reagent consumption, which can be well used for the detection of the pyrethroids in tea brew.

Cathodic stripping voltammetric determination of β-cyfluthrin, a pyrethroid insecticide, using polished silver solid amalgam electrode

“…These values were similar to previously values observed using HMDE [18], but were obtained without generation of waste toxic from the use of mercury. Besides, these calculate values were similar to previously obtained using GC-MS allied to SPE [34] or HPLC-MS using dispersive liquid-liquid microextraction [35], indicating that the p-AgSAE allied to SWCASV is a suitable procedure to evaluate traces of βCF.…”

“…The linearity coefficient was 0.9983, indicating a good linearity of the GC-MS procedure employed in this work [33]. As the interception presented negative values, "t" test was performed and indicated that the average analytical curve was free from random errors [34]. DL and QL values were calculated using GC-MS in order to compare the efficiency of the electroanalytical procedure proposed in this work, and data are shown in Table 1, shown in Supplementary Data.…”

Use of 1‐octyl‐3‐methylimidazole hexafluorophosphate modified magnetic hyperbranched polyamideamine as sorbent for the extraction of pyrethroid insecticides from tea infusion

“…To extract target analytes from different samples, dispersive SPE [6], SPME [7, 8], spin‐column micro‐SPE [9], LPME [10, 11] and magnetic solid‐phase extraction (MSPE) [12–15] were adopted by researchers. Among these technologies, MSPE is worthy of attention due to its rapid solid‐liquid separation with the help of magnets, high enrichment factors, and low solvent consumption [16].…”