Aela Agela Technologies

Advance search
Quick Order
See your previous items:
You have 0 product(s) in cart

Simultaneous Detection of 112 Kinds of Pesticide Residues in the Black Tea using Extraction-type QuEChERS

Application Introduction

To increase production and income, the tea gardens have long been using highly effective pesticides to control diseases and pests, leading to excessive pesticide residues in some of the tea products.

Favorite

Introduction

To increase production and income, the tea gardens have long been using highly effective pesticides to control diseases and pests, leading to excessive pesticide residues in some of the tea products. Red tea as a kind of drink is a target for strict regulation of detection limit in many countries. And this article also introduces the QuEChERS-LC-MS/MS method for extracting and testing 112 types of pesticide residues in red tea.

Experimental

Sample extraction

Weigh 2.0 g of tea powder, and transfer it in a 50 mL centrifuge tube. Add 10 mL of water into the tube, and leave it stand still for 1h. Add 15 mL of acetonitrile, 4.0 g of magnesium sulfate and 1.0 g of sodium chloride (P/N: MS-MG5055). Keep violently oscillating the tube manually for 1min and keep centrifuging the tube at 8,000 rpm for 5min, and then reserve 1 mL of supernate for purification.

Sample purification

Connect Bonna-Agela Cleanert® NANO special purification columns (P/N: IC-NN1510-C) for agricultural complex matrixes in series with 10 mL one-time needle tubes. Extract 1 mL of extracting liquid, and then push out the liquid. Repeat this step for 3 times. Filter the liquid with a 0.22 µm organic membrane for the next LC-MS/MS determination.

Preparation of matrix-mixed standard working solution

Dilute the high-concentration pesticide-mixed standard solution with blank sample matrix solution to the matrix-mixed standard working solution (concentration: 0.02 μg/mL).

Instrumentation

Chromatographic columns: Venusil® ASB C18 (5 μm, 150 Å, 2.1 × 150 mm);

Mobile phases:

Phase A: Formic acid aqueous solution (concentration: 0.1%)

Phase B: Formic acid -acetonitrile solution (concentration: 0.1%);

Column temperature: 30 °C;

Sample size: 10 µL;

Gradient elution conditions (see Table 1);

Ion source: ESI source;

Scanning mode: Positive ion scanning;

ESI voltage: 5500 V;

Atomized gas pressure: 50 psi;

Curtain gas pressure: 15 psi;

Auxiliary gas pressure: 50 psi;

Ion source temperature: 400 °C;

Collecting mode: MRM.

Figure 1 LC Gradient Elution Conditions

Time/min

Flow rate

/(mL/min)

A/%

B/%

0.00

0.30

99

1

3.00

0.30

70

30

6.00

0.30

60

40

9.00

0.30

60

40

15.00

0.30

40

60

19.00

0.30

1

99

23.00

0.30

1

99

23.01

0.30

99

1

40.00

0.30

99

1

Results and Discussion

Figure 1 LC-MS/MS Chromatogram of Mixed Standard Solution (concentration: 0.02 μg/mL)

Figure 2 Blank LC-MS/MS Chromatogram of Black Tea Sample

Figure 3 LC-MS/MS Chromatogram of Black Tea Matrix–mixed Standard Working Solution (concentration: 0.02 μg/mL)

Figure 4 LC-MS/MS Chromatogram of Black Tea Matrix Sample with Standard Addition (content: 0.15 mg/kg)

Conclusion

This experiment establishes the LC-MS/MS method for detecting pesticide residues, and determines the contents of pesticide residues in the black tea on the basis of solid phase extraction technology. The samples (standard addition amount: 0.15 mg/kg) are detected, and the resulted recovery rates are between 60% and 110%, conforming to requirements. The stable QuEChERS effect and good reproducibility of chromatographic columns show this method can be applied to the detection of pesticide residues in the black tea.

 Order Information

Products

Specification

Cat.No

Venusil®   ASB C18

5 μm, 150 Å, 2.1   × 150 mm

VS951502-0

Cleanert®   NANO

10 mg Nano, 150   mg MgSO4

IC-NN1010-V

MAS-QuEChERS   Cleanup Kits

15 mg Nano, 150   mg MgSO4

IC-NN1510-C

Guard cartridge   holder

Suitable for 4.6 ×   10 mm and 2.1 × 10 mm

SH-100

Direct-coupled   protect column core

5 μm, 150 Å, 2.1×10 mm, 4/pk

VS950102-0S

1.5 mL vials

Screw neck vials,   12 × 32 mm

AV1001-6

Caps and Septa

Screw neck cap,   center hole; red silicone/white PTEE septa, slitted

AV2200-0

Syringe Filter (Nylon)  

Monofilm, 13 mm,   0.22 μm

AS021320

Disposable   Needle-Free injection systems

2 mL, 100/pk

LZSQ-2ML

 

Material Name Material Type Date
Modify product number success!
Total Price:

Close

Email To Sombody

X
Email
Subject
Content

Login

X
Email address
Password
Register Forgotten your password?