Ph meter pb

The chemicals and reagents such as the stock standard solution (100 mg/kg) for pesticide Baycarb, Carbaryl, Diazinon, Dursban, Metalaxyl, Propamocarb, Thiamethoxam and Thiobencarbwere were purchased from AccuStandard ® (New Haven, USA). The LC-MS grade organic solvents that include ACN and methanol were purchased from Merck (Germany). The formic acid was purchased from Fisher Scientific. The Millipore-filtered (deionized) water was obtained using Merck Millipore water purification system (Billerica, USA). While, the apparatus and equipments that include the 100 and 500 µL microsyringe were purchased from Agilent (Australia). The pH meter PB was purchased from Sartorius group (Germany). The HPLC autosampler vials were purchased from Agilent Technologies (USA). The Supelco HPLC column [Ascentis ® Express C18 (5 cm x 2.1 mm, 2.7 µm)] was purchased from Sigma-Aldrich (USA). And the liquid chromatography-tandem mass spectrometry (LC-MS/MS) [triple quadrupole (G6490A) built in Electrospray ESI (±) MS/MS Sensitivity and Jet stream Technology] instrument was purchased from Agilent (Singapore).

The 2, 15, and 50 mL polypropylene centrifuge tubes by LabServ Fisher-Scientific (Kuala Lumpur, Malaysia), and 100 and 500 µL microsyringes were obtained from Agilent (Australia). The HPLC autosampler vials were purchased from Agilent Technologies (USA) and other equipments such as Dynamica refrigerated centrifuge by CNG instruments (Selangor, Malaysia), vortexer VTX-3000L by Copens Scientific (Tokyo, Japan) and glass jug blender MX-GX1581WSK (Panasonic, Malaysia) and Supelco HPLC column [Ascentis ® Express C18 (5 cm x 2.1 mm, 2.7 µm)] (Sigma-Aldrich, USA). The others include weighing balance (Sartorius Technology Park, Germany), pH meter PB (Sartorius group, Germany) and Agilent triple quadrupole LC/MS G6490A [built in Electrosprays ESI (±) MS/MS Sensitivity and Jet stream Technology] instrument (Singapore).