Graphitized carbon black (gcb)

Tolfenpyrad (98.0% purity) was purchased from Beijing J&K Scientific Co., Ltd. (Beijing, China). The commercial formulation included suspension concentrate (SC) containing 15% Tolfenpyrad and was provided by Hailir Pesticides and Chemicals Group (Qingdao, China). Acetonitrile (ACN), acetone, methanol (MeOH), ethyl acetate (EA), acetic acid (AA), sodium chloride (NaCl) and anhydrous magnesium sulfate (MgSO₄) were purchased from Chengdu Jinshan Chemical Reagent Company (Chengdu, China). Primary secondary amine (PSA), octadecylsilane (C₁₈) and graphitized carbon black (GCB) were purchased from Bonna-Agela Technologies Co., Ltd. (Tianjin, China). Syringe filters (0.22 µm, nylon) were obtained from PeakSharp Technologies (Beijing) Co., Ltd. (Beijing, China).
The stock solution was prepared by weighing 0.0101 g of Tolfenpyrad standard into a 100 mL volumetric flask and was then dissolved using chromatographic grade acetone at a concentration of 101 µg/mL. The standard working solutions at concentrations of 0.005, 0.05, 0.1, 0.5, 1, 5, and 10 µg/mL were diluted with acetone. Matrix-matched standard solutions of Tolfenpyrad were prepared in blank BBL, SOL, LSL and BCL samples for calibration and quantitation. All solutions were stored at −20 °C in the dark and were stable for one month.

A total of nine TKIs standard substances were purchased from the Shanghai Yuanye Biotechnology Co., Ltd. (Shanghai, China). Propranolol was supplied by the China National Institute for China Drug and Biological Products Control. HPLC-grade methanol (MeOH), ethyl acetate (EtOAc), and acetone (CP) were purchased from Merck Drugs & Biotechnology (Darmstadt, Germany). HPLC-grade formic acid (FA) and acetic acid (HOAc) were purchased from Dikma (Beijing, China); LC/MS-grade acetonitrile (ACN) was acquired from ThermoFisher Scientific (Shanghai, China). Analytical-grade anhydrous magnesium sulfate (MgSO₄) was purchased from the Tianjin Damao Chemical Reagent Factory (Tianjin, China). Octadecyl bonded silicagel (C18), florisil adsorbents, and graphitized carbon black (GCB) were supplied by Agela Technologies (Tianjin, China). NH₂ and ethyl enediamine-N-propylsilane (PSA) were purchased from Agilent Technologies (Shanghai, China).

Standard bentazone (purity was 99.7%), 6-hydroxy-bentazone (purity was 99.2%), 8-hydroxy-bentazone (purity was 99.5%), and dichlorprop-P (purity was 99.7%) were purchased from Ehrenstorfer GmbH, Augsburg, Germany; The individual stock standard solutions (1000 mg/L) of four analytes were dissolved with Acetonitrile and stored at −20 °C, respectively. The individual work standard solutions (100 mg/L) were also prepared for daily use and stored at −20 °C. Acetonitrile was supplied by Fisher Scientific (Pittsburgh, PA, USA) in HPLC grade. Formic acid (98% purity) was purchased from Sinopharm Chemical Reagent Co. Ltd., Shanghai, China. Anhydrous magnesium sulfate (MgSO₄) and sodium chloride (NaCl) purchased from Beijing Reagent Company (Beijing, China) were baked at 110 °C for 8 h. The Agela Cleanert C₁₈ (40–60 μm), Primary secondary amine (PSA) and graphitized carbon black (GCB) were from Agela Technologies, Tianjin, China. The formulation, 566 g/L dichlorprop-P bentazone soluble liquid (SL), was kindly provided by BASF, Beijing, China. The 0.1% Formic acid water solution was prepared before sample extraction. Ultrapure water was obtained from Aquapro Ultrapure Water System (Aquapro International Company LLC, Chongqing, China).

Chromatographic-grade methanol and acetonitrile were purchased from Thermo Fisher Scientific (Waltham, MA, USA), formic acid was purchased from Sigma–Aldrich (St. Louis, MO, USA), ammonium acetate and ethyl acetate were purchased from the Beijing Chemical Factory (Beijing, China), pydiflumetofen standard (purity 99.7%) was purchased from Dr. Ehrenstorfer GmbH (Augsburg, Germany), and 20% pydiflumetofen soluble concentrate (SC) was purchased from Syngenta Crop Protection Co., Ltd. (Kunshan, China).
Primary secondary amine (PSA, 40–60 μm), end-capped octadecyl carbon (C₁₈, 50 μm), and graphitized carbon black (GCB, 38–125 μm) were purchased from Agela Technologies (Shanghai, China); Multiwalled carbon nanotubes (MWCNTs)–XFM40 (diameter 10–20 nm, length 5–30 μm), XFM25 (diameter 30–50 nm, length < 10 μm), and XFM04 (diameter 5–15 nm, length 0.5–2 μm) were purchased from Xianfeng Nanomaterials Technology Co., Ltd. (Nanjing, China). Wahaha Group Co., Ltd. (Hangzhou, China) supplied purified water. Sodium chloride (NaCl) and magnesium sulfate (MgSO₄) were purchased from Guangdong Xilong Science Co., Ltd. (Shantou, China). Polyethylene centrifuge tubes of 5- and 50-mL volumes were purchased from Biosharp Corporation (Hefei, China), and an organic membrane of pore size 0.22 μm was purchased from Jinteng Experimental Equipment Co., Ltd. (Tianjin, China).

The certified reference materials of 54 pesticides (Table 1) in this work (≥98.0%) were purchased from the Agro-environmental Quality Supervision, Inspection & Testing Center (Tianjin, China). Methanol (HPLC grade) was obtained from Merck (Darmstadt, Germany). Acetonitrile (HPLC grade) was purchased from Tedia Company (Fairfield, OH, USA). Acetic acid (HPLC grade) and formic acid (HPLC grade) were from Fisher Regent Company (Beijing, China). Ammonium acetate (HPLC grade) was from Tianjin Guangfu Fine Chemical Research Institute (Tianjin, China), QuEChERS extraction salts pachets (4 g magnesium sulfate, 1 g sodium chloride, 1 g sodium citrate and 0.5 g disodium citrate sesquihydrate) were provided by Shimadzu Corporation. Anhydrous magnesium sulfate (MgSO₄) (>99.0%) was from Sinopharm Chemical Reagent Co., Ltd. (Beijing, China). Primary secondary amine (PSA, 40–60 μm), graphitized carbon black (GCB, 120–400 Mesh), and octadecylsilane (C₁₈, 50 μm, 60 A) were from Agela Technologies Inc. (Tianjin, China).

Magnesium sulfate and sodium chloride were purchased from Sinopharm Chemical Reagent Co., Ltd. (Beijing, China). GC-grade dichloromethane (≥99% purity) was purchased from Merck Chemical Co. Inc. (Darmstadt, Germany). OTA and 4-methyl-2-pentanol were purchased from Sigma-Aldrich (St. Louis, MO, USA). n-Alkanes (C7–C30) were obtained from Supelco (Bellefonte, PA, USA). Primary secondary amine (PSA), C18 (octadecyl) and graphitized carbon black (GCB) were purchased from Agela Technologies (Tianjin, China). Graphite powder (99.8%) was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. (Shanghai, China). HPLC-grade acetonitrile (ACN) and formic acid (99% purity) were purchased from Merck (Darmstadt, Germany). Ultra-pure water was obtained using a Milli-Q purification system (Millipore, Bedford, MA, USA).