Page 48 - Application Handbook - Liquid Chromatography

LAAN-A-LC-E273

Application Supercritical Fluid Extraction / Chromatography

News Using the Nexera UC Online SFE-SFC-MS System to

Analyze Residual Pesticides in Agricultural Products
No.L497

The Nexera UC online SFE-SFC-MS system combines n Sample Preparation
supercritical fluid extraction (SFE) and supercritical fluid The QuEChERS is a well-known method that prioritizes
chromatography (SFC) in one online system, so that the simplicity and speed and is commonly used to pretreate
entire process from extraction of target components to agricultural products for residual pesticide analysis. However,
acquisition of data can be performed completely the method involves many steps, such as adding reagents,
automatically. Furthermore, the system can add polar solvent extraction, purification by dispersive solid phase
organic solvents (modifiers) to the supercritical carbon extraction, and centrifugal separation. In contrast, the online
dioxide fluid during SFE and SFC, so that the system SFE-SFC-MS system requires only mixing 1 g of agricultural
can be used to extract and analyze components with a product crushed with a mixer with 1 g of a dehydrating
wide range of polarities. agent* and placing the mixture in the extraction vessel, as
Meanwhile, ever since the positive list system was shown in Fig. 2. Consequently, the system improves
enacted in 2006 in Japan for residual pesticides in analytical productivity, reduces the environmental impact,
foods, which applies to more than 800 types of and also avoids human errors involved in the pretreatment
pesticides, there has been increasing demand for a steps. Using a dedicated rack changer, the system can
system able to simultaneously analyze multiple continuously extract and analyze up to 48 samples at a time.
pesticides with a wide range of properties, including
pretreating samples. * "Miyazaki Hydro-Protect" Patent No. 3645552
This article describes an example of using the Nexera Extraction vessel
UC online SFE-SFC-MS system to analyze residual (A) Analytical column
Analytical column
Analytical column
Analytical column
Analytical column
pesticides in agricultural products. Back pressure Mass
Back pressure
Back pressure
regulator (BPR-A)
regulator (BPR-B)
Valve
Valve
Valve
Valve Valve regulator (BPR-A) spectrometer
Valve
Valve
Valve
SFE unit
SFE unit
SFE unit
n Online SFE-SFC-MS System Back pressure
Back pressure
Back pressure
Back pressure
Back pressure
regulator (BPR-B)
regulator (BPR-B)regulator (BPR-B)
regulator (BPR-B)
The operating principle of the Nexera UC online SFE- Modifier Make-up
Make-up
Make-up
Make-up
Make-up
Make-up
SFC-MS system is shown in Fig. 1. The extraction vessel CO2 cylinder
filled with the sample is placed in the SFE unit and (B) Extraction vessel
Extraction vessel
Extraction vessel
heated to an internal temperature of 40 °C (Fig. 1A). Analytical column
Analytical column
Analytical column
Analytical column
Analytical column
Mass
Back pressure
Back pressure
Back pressure
Then supercritical carbon dioxide fluid is pumped into Valve Valve regulator (BPR-A) spectrometer
regulator (BPR-A)
regulator (BPR-B)
Valve
Valve
Valve
Valve
Valve
Valve
the extraction vessel. After filling the vessel, the flow is SFE unit
SFE unit
SFE unit
Back pressure
stopped to allow static extraction of target components regulator (BPR-B)
(Fig. 1B). After static extraction, the fluid is pumped CO2 cylinder Modifier Make-up
Make-up
Make-up
Make-up
Make-up
through the extraction vessel for dynamic extraction
(Fig. 1C). During dynamic extraction, extracted Extraction vessel
Extraction vessel
Extraction vessel
substances flow from the extraction vessel and into the (C)
Analytical column
Analytical column
Analytical column
Analytical column
analytical column. However, due to the high level of Analytical column Back pressure spectrometer
Mass
Back pressure
Back pressure
regulator (BPR-B)
regulator (BPR-A)
Valve
Valve
Valve
contaminant components in agricultural products, Valve SFE unit Valve regulator (BPR-A)
Valve
Valve
Valve
SFE unit
SFE unit
passing all the extract substances through the analytical Back pressure
column or mass spectrometer could damage the regulator (BPR-B)
column or contaminate the mass spectrometer. CO2 cylinder Modifier Make-up
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Make-up
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Make-up
Therefore, the Nexera UC online SFE-SFC-MS system Extraction vessel
Extraction vessel
Extraction vessel
splits the flow to send only a portion of the substances (D)
Analytical column
Analytical column
Analytical column
Analytical column
extracted from dynamic extraction through the Analytical column Back pressure spectrometer
Mass
Back pressure
Back pressure
regulator (BPR-A)
regulator (BPR-A)
Valve
Valve
Valve
Valve
Valve
Valve
analytical column. After dynamic extraction, fluid is only Valve SFE unit Valve regulator (BPR-B)
SFE unit
SFE unit
sent through the analytical flow line, where the regulator (BPR-B)
Back pressure
analytical column is used for gradient separation and
the mass spectrometer for detecting the target CO2 cylinder Modifier Make-up
Make-up
Make-up
Make-up
Make-up
components (Fig. 1D).
Fig. 1 Analysis Flow by Online SFE-SFC-MS
Pretreatment process for conventional (QuEChERS) method
Pulverize Add solvent Stir Add reagent Stir Centrifuge Acquire supernatant Add reagent Stir Centrifuge
Mix agricultural products Rack changer
Pretreatment for Nexera UC system and dehydrating agent
Add dehydrating Fill extraction
Pulverize Mix
agent vessel
Fig. 2 Sample Preparation