Pesticide extraction efficiency of two solid phase disk types after shipping.

Area of Science:

• Environmental Chemistry
• Analytical Chemistry

Background:

• Solid phase extraction (SPE) disks are crucial for analyzing pesticides in water.
• Comparing the performance of different SPE disk materials is essential for method optimization.

Purpose of the Study:

• To compare pesticide recovery rates between Empore C(18) and Speedisks C(18)XF solid phase extraction disks after shipping.
• To evaluate Speedisks C(18)XF as a potential alternative to Empore disks for water sample analysis.

Main Methods:

• An interlaboratory study was conducted using four pesticides (atrazine, diazinon, metolachlor, tebuconazole) with varying physiochemical properties.
• Water samples were extracted using both Empore C(18) and Speedisks C(18)XF, then shipped for elution and analysis.
• Pesticide recovery percentages were calculated for each disk type.

Main Results:

• Mean pesticide recoveries were: Empore disks (atrazine 95%, diazinon 91%, metolachlor 92%, tebuconazole 83%) and Speedisks C(18)XF (atrazine 89%, diazinon 87%, metolachlor 86%, tebuconazole 79%).
• No statistically significant differences in mean recoveries were observed between the two disk types (alpha = 0.05).
• Results showed increased variability with Speedisks C(18)XF compared to Empore disks.

Conclusions:

• Speedisks C(18)XF can be considered a suitable alternative to Empore disks for pesticide analysis.
• The plastic housing of Speedisks C(18)XF offers practical advantages for field use, including reduced breakage risk and no need for prefiltration.
• Potential reasons for increased variability with Speedisks C(18)XF were discussed.