Waters DisQuE Dispersive Sample Preparation Kit - Manual (Page 2)

D is Q u E QuEChERS Sample Preparation Products and Kits 2
[ Care and Use ManUal ]
II. KIt Contents
DisQuE QuEChERS Sample Preparation kits are designed for preparing
samples for routine multi-pesticide residue analysis. The kits are
available in the following configurations:
Kit for AOAC Official Methods
Name Description
DisQuE Dispersive SPE
Kit–Pouch Format
(AOAC Method 2007.01) Pouch: 1.5 g sodium acetate and 6 g MgSO
4
50 mL Tube: Empty
2 mL Tube: 150 mg MgSO
4
and 50 mg PSA
DisQuE Dispersive SPE
Kit–Pouch Format
(CEN Method 15662)
Pouch: 1 g trisodium citrate dihydrate, 0.5 g
disodium hydrogencitrate sesquihydrate, 1 NaCl
and 4 g MgSO
4
50 mL Tube: Empty
2 mL Tube: 150 mg MgSO
4
, 25 mg PSA, and 25 mg C
18
DisQuE Dispersive SPE Kit
(AOAC Method 2007.01) 50 mL Tube: 1.5 g sodium acetate, 6 g MgSO
4
2 mL Tube: 150 mg MgSO
4
, 50 mg PSA
DisQuE Dispersive SPE Kit
(CEN Method 15662)
50 mL Tube: 4 g MgSO
4
, 1 g NaCl, 1 g trisodium
citrate dehydrate, 0.5 g disodium
hydrogencitrate sesquihydrate
2 mL Tube: 150 mg MgSO
4
, 25 mg PSA, 25 mg C
18
III. IndIvIduAl PouCHes, eXtrACtIon tubes,
CleAnuP tubes, And bulK sPe sorbents
Extraction Tubes
Name Description
50 mL Empty Tube for
QuEChERS Extraction
–
50 mL Tube–Blue Cap
(AOAC Method)
1.5 g sodium acetate, 6 g MgSO
4
50 mL Tube–White Cap
(CEN Method)
4 g MgSO
4
, 1 g NaCl, 1 g trisodium citrate
dehydrate, 0.5 g disodium hydrogencitrate
sesquihydrate
Sorbent Pouches
Name Contents
DisQuE Pouch
(AOAC Method)
1.5 g sodium acetate, 6 g MgSO
4
DisQuE Pouch
(CEN Method)
4 g MgSO
4
, 1 g NaCl, 1 g trisodium citrate
dehydrate, 0.5 g disodium hydrogencitrate
sesquihydrate
Clean-Up Tubes
Name Contents
2 mL Tube–White Cap 150 mg MgSO
4
, 50 mg PSA
2 mL Tube–Blue Cap 150 mg MgSO
4
, 50 mg PSA, 25 mg C
18
2 mL Tube–Yellow Cap 150 mg MgSO
4
, 25 mg PSA
2 mL Tube–Green Cap 150 mg MgSO
4
, 25 mg PSA, 25 mg C
18
15 mL Tube–White Cap 900 mg MgSO
4
, 150 mg PSA
15 mL Tube–Blue Cap 900 mg MgSO
4
, 150 mg PSA, 150 mg C
18
Bulk Sorbent
Name Qty
Graphitized Carbon Black 25 g
Trifunctionally-bonded C
18
Silica 100 g
Iv. ProCedure overvIew
1. Sample Comminution
The sample is coarsely cut before pulverization by a food chopper,
blender, or other similar device. The sample size (10–15 g) used in
the DisQuE procedure is reduced compared with the traditional extrac-
tion procedures; therefore, it is important to ensure that the original
sample is thoroughly homogenized. Blending the sample until it
reaches a consistent texture reduces the variation in the sub-sample
that will be used for testing and ensures better extraction efficiency.
During the homogenization process, the use of cryogenic blending
devices, liquid nitrogen, or dry ice is recommended to reduce the loss
of highly-volatile or thermally-labile pesticides.
2. Sample Extraction/Partitioning
The sub sample is transferred to an empty 50 mL DisQuE extraction
tube. Depending on whether you are utilizing the AOAC or CEN
QuEChERS method, the method appropriate foil pouch containing pre-
weighed salts is selected. The salts are added to the extraction tube
followed by the extraction solvent. During mixing, shake, and invert
the extraction tube vigorously to ensure that the sample is thoroughly
mixed with the extraction buffers contained in the tube. The shaken
sample is centrifuged, and the extract from Tube 1 is used for further
clean-up. The centrifuge rpm and time should be optimized to ensure
a solid sample plug and clean extract free from particulate matter.
Note: When the samples are mixed with anhydrous anhydrous magne-
sium sulfate excessive heat may be generated. It is recommended to
vent the tube after a few shakes to release any gas pressure.