Holstege, Dirk

Adjunct Professor
224 Hoagland Hall
Phone: (530) 752-0148
Fax: (530) 752-9892
Email: dmholstege@ucdavis.edu




Development of analytical methodologies for chemical analysis in soil, plant tissue, biological materials, and water. Analysis for naturally-occurring toxins of plant origin. Trace metal analysis and trace organic analysis. Application of LC/MS/MS for trace analysis.


  • Agricultural & Environmental Chemistry, University of California, Davis, 1995 PhD
  • Biochemistry, University of California, Davis, 1981 B.S.


  • ETX 111 - Introduction to Mass Spectrometry
  • ETX 228 - Gas Chromatography/Mass Spectrometry of Toxic Chemicals

Professional Activities:

Recent Publications:

Holstege DM, Scharberg DL, Richardson ER, Moller G. Multiresidue screen for organophosphorus insecticides using gel permeation chromatography--silica gel cleanup. J Assoc Off Anal Chem. 1991 Mar-Apr;74(2):394-9.

Holstege DM, Scharberg DL, Tor ER, Hart LC, Galey FD. A rapid multiresidue screen for organophosphorus, organochlorine, and N-methyl carbamate insecticides in plant and animal tissues. J AOAC Int. 1994 Sep-Oct;77(5):1263-74.

Tor ER, Holstege DM, Galey FD.Determination of cholinesterase activity in brain and blood samples using a plate reader. J AOAC Int. 1994 Sep-Oct;77(5):1308-13.

Galey FD, Holstege DM, Plumlee KH, Tor E, Johnson B, Anderson ML, Blanchard PC, Brown F. Diagnosis of oleander poisoning in livestock. J Vet Diagn Invest. 1996 Jul;8(3):358-64.

Holstege DM, Francis T, Puschner B, Booth MC, Galey FD. Multiresidue screen for cardiotoxins by two-dimensional thin-layer chromatography. J Agric Food Chem. 2000 Jan;48(1):60-4.

Holstege DM, Puschner B, Le T. Determination of grayanotoxins in biological samples by LC-MS/MS. J Agric Food Chem. 2001 Mar;49(3):1648-51.

Holstege DM, Puschner B, Whitehead G, Galey FD. Screening and mass spectral confirmation of beta-lactam antibiotic residues in milk using LC-MS/MS. J Agric Food Chem. 2002 Jan 16;50(2):406-11.

TenBrook PL, Viant MR, Holstege DM, Williams JF, Tjeerdema RS. Characterization of California rice field soils susceptible to delayed phytotoxicity syndrome. Bull Environ Contam Toxicol. 2004 Sep;73(3):448-56.

Owens JE, Holstege DM, Clifford AJ. Quantitation of total folate in whole blood using LC-MS/MS. J Agric Food Chem. 2005 Sep 21;53(19):7390-4.

Faber, B. A., Downer, A. J., Holstege, D. M., Mochizuki, M. J. Accuracy Varies for Commercially-available Soil Test Kits Analyzing N, P, K and pH, Horticultural Technology. 17: 358-362, 2007.

Owens J. E., Holstege D. M., Clifford A. J. Comparison of Two Dietary Folate Intake Instruments and Their Validation by RBC Folate. Journal of Agricultural and Food Chemistry. 55, 3737-3740, 2007.

Owens J. E., Holstege D.M., Clifford A. J. High-throughput method for the quantitation of total folate in whole blood by LC-MS/MS. Journal of Agricultural and Food Chemistry. 55, 3292-3297, 2007.

Tomco, P., Holstege, D. M., Tjeerdema, R. Microbial degradation of clomazome under simulated California rice growing conditions. Journal of Agricultural and Food Chemistry. 58, 3674-3680, 2010.

Panter. K. E., Gardner, D. E., Stegelmeier, B. L., Welch, K. D., Holstege, D. M. Water hemlock poisoning in cattle: Ingestion of immature Cicuta maculata seed as the probable cause. Toxicon 57 157–161, 2011