CALTEST INFORMATIONAL BULLETIN
June 2006
SUMMARY POINTS RELATED TO ANALYSIS:
Method of analysis uses an existing, promulgated method modified by adding analytes ( pyrethroids ), and using the mass spec capabilities defined in the method. EPA method 8270 is followed, with a pyrethroid / pyrethrin analyte list, and acquiring data narrow range scan for the three most abundant ions per analyte instead of full scan. The method specifies three ions per analyte, and specifically allows for selected ion monitoring . The goal is to reach the sensitivity needed with least modification of existing approved methods .
EPA METHOD 8270 HIGHLIGHTS
- Standard electron ionization, quadrupole Mass Spec
- Scanning narrow amu range, 3 ions per analyte extracting quant ion, qualifying ion, monitoring ion.
- Analyte Reporting Limit supported by both low calibration standard and MDL (incorporated extraction efficiency and precision).
- Initial Calibration using at least five concentrations
- Second Source Calibration verification standard
- Then method QC: method blank, laboratory control sample and duplicate, matrix spike sample and matrix spike duplicate
- Use of Internal Standard method
- Includes two extraction surrogates reported with result
- No extraction correction applied – consistent with EPA Clean Water Act methods
- Laboratory Control Standard and Matrix Spike recoveries reported
- Perform Method Detection Limit Study per 40 CFR Part 136 Appendix B
- Demonstrate recoveries in matrix
- Analyst demonstrates proficiency with four laboratory control standards
- Retain retention time studies, MDLs, analyst proficiency data sets for regulatory review.
REFERENCES:
The following references each use GCMS for pesticides , including pyrethroids :
Caltest’s work is conceptually based on the method published by the USGS:
Sandstrom MW, Stroppel ME., Foreman WT, Schroeder MP. 2002. Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory-Determination of Moderate-Use Pesticides and Selected Degredates in Water by C-18 Solid Phase Extraction and Gas Chromatography/Mass Spectrometry. Water Resources Investigations Report 01-4098, U.S. Geological Survey Method O-2002-01, USGS Denver, Colorado
Caltest’s work is also based on USGS:
Zaugg SD, Sandstrom MW, Smith SG, Fehlberg KM. 1995. Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory—Determination of Pesticides in Water by C-18 Solid-Phase Extraction and Capillary-Column Gas Chromatography/Mass Spectrometry with Selected Ion Monitoring
Caltest’s work is also based on:
White J, Feng H, Cooper C, Rivera L, Jackson T. 2003. Determination of Pyrethroids in Sediment Water. EMON-SM-52-7. California Dept. of Food and Agriculture, Center for Analytical Chemistry, Environmental Monitoring Section, Sacramento, CA
Current Use of GC/MS Selected Ion Monitoring of Pyrethroid Pesticides in Waters and Sediments:
Smalling, K.L., Orlando, J.L., and Kuivila, K.M., 2005, Analysis of Pesticides in Surface Water and Sediment from Yolo Bypass, California, 2004-2005: U.S. Geological Survey Scientific Investigations Report 2005-5220, 20p.
Work in cooperation with the California Bay-Delta Authority
http://pubs.usgs.gov/sir/2005/5220/USGS_2005-5220.pdf
and:
LeBlanc, L.A., Schroeder, R.A., Orlando, J.L., and Kuivila, K.M., 2004, Pesticide concentrations in water and in suspended and bottom sediments in the New and Alamo Rivers, Salton Sea watershed, April 2003: U.S. Geological Survey Data Series Report 104, 15p
Work in Cooperation with California State Regional Water Quality Control Board, Colorado River Region.
http://pubs.usgs.gov/ds/ds104/ds104.pdf
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