Waters DisQuE Dispersive Sample Preparation Kit - Manual (Page 3)

D is Q u E QuEChERS Sample Preparation Products and Kits 3
[ Care and Use ManUal ]
Tip: For some commodities that contain a high water content, it is
recommended that the extraction solvent is added to the 50 mL
extraction tubes prior to the addition of the sample. This prevents
undesirable caking of the anhydrous magnesium sulfate to the sample.
3. Dispersive Solid-Phase Extraction
A 1 mL aliquot of the top layer extract from the 50 mL extraction
tube is transferred to the 2 mL DisQuE clean-up tube. Shake the tube
vigorously and invert the tube a few times to ensure the extract is
thoroughly mixing with all the solids in the 2 mL tube. The sample
can be analyzed directly or diluted appropriately with a suitable
buffer or solvent.
v. usIng tHe AoAC KIt And MetHod
The following section describes the general steps involved for a using
DisQuE QuEChERS sample preparation kits for the AOAC (Association
of Analytical Communities) procedure.
Extraction solution preparation
A solution of 1% acetic acid in acetonitrile is prepared by adding
10 mL of glacial acetic acid to 500 mL of acetonitrile in a
1 L volumetric flask. Bring to final volume with acetonitrile. Mix
thoroughly.
1. Sample Comminution
The sample is chopped into 2–5 cm
3 portions with a knife, and then
pulverized by a food blender. Blend until homogeneous.
2. Extraction/Partitioning
Add 15 mL of 1% acetic acid followed by the contents of the AOAC
salt pouch to an empty 50 mL extraction tube. Manually shake a few
times to ensure that no solids are stuck to the bottom of the tube.
Transfer 15 g of the homogenized sub sample into the extraction
tube. Shake vigorously for 1 minute. Centrifuge the tube at > 1500
rcf for at least 1 minute. Caution: exceeding 10,000 rcf may dam-
age, deform, or break the extraction tube.
3. Dispersive Solid-Phase Extraction
Transfer 1 mL of top layer extract from Tube 1 into the 2 mL DisQuE
Clean-Up Tube 2. Shake vigorously for at least 30 seconds ensuring
the sample and sorbents are thoroughly mixed. Centrifuge Tube 2
at > 1500 rcf for 1 minute. Caution: exceeding 17,000 rcf may
damage, deform, or break the centrifuge tube. Transfer the top
extract into and autosampler vial for analysis.
vI. stePs oF sAMPle CoMInutIon And solId-PHAse
eXtrACtIon usIng Cen KIt And MetHod
The following section describes the general steps involved for a using
DisQuE QuEChERS sample preparation kits for the CEN procedure.
1. Sample Comminution
The sample is chopped into 2–5 cm
3 portions with a knife, and then
pulverized by a food blender. Blend until homogeneous.
2. Extraction/Partitioning
Add 10 mL of acetonitrile and the contents of the CEN method salt
pouch to a 50 mL extraction tube. Manually shake a few times to
ensure that no solids are stuck to the bottom of the tube. Transfer
10 g of the homogenized sub sample into the extraction tube. Shake
vigorously for 1 minute. Centrifuge the tube at > 1500 rcf for at
least 1 minute. Caution: exceeding 10,000 rcf may damage, deform,
or break the extraction tube.
3. Dispersive Solid-Phase Extraction
Transfer 1 mL of top layer extract from Tube 1 into the 2 mL DisQuE
Clean-Up Tube 2. Shake vigorously for at least 30 seconds ensuring
the sample and sorbents are thoroughly mixed. Centrifuge Tube 2 at
> 3000 rcf for 5 minutes. Transfer the top extract into and autosam-
pler vial for analysis. Caution: exceeding 17,000 rcf may damage,
deform, or break the centrifuge tube.
vII. storAge And dIsPosAl oF used CArtrIdges
The devices remain stable when stored in their original sealed pack-
aging. To store unused devices in opened pouches, squeeze the air
out of the pouch, fold over the open end of the pouch twice, seal with
tape, and store in a desiccator.
Dispose of used devices safely in accordance with applicable govern-
ment or local regulations.
vIII. AddItIonAl InForMAtIon
For more detailed information, consult the Waters Quality Parts ® ,
Chromatography Columns and Supplies Catalog by visiting
www.waters.com/catalog, or contact your Waters representative.
If you require technical assistance, or have any questions
regarding sample preparation, visit www.waters.com or call us at
1-800-252-4752.