urrently, little is known about the occurrence, fate, or transport of sulfonylurea (SU), sulfonamide (SA), 

and imidazolinone (IMI) herbicides in surface water or ground water in the United States. To gain an 

understanding of the occurrence of these herbicides in an unbiased yet economical manner, a 

Cooperative Research and Development Agreement (CRADA) between the U.S. Geological Survey (USGS) 

and DuPont Agricultural Products (DuPont) has been developed. As a result of this cooperative effort, the 

USGS will (1) collect data that can be used to assess the presence of twelve SUs, three IMIs, and one SA in 

water resources of the midwestern United States; and (2) develop an analytical method for SUs, IMIs, and 

SAs that is similar in terms of analyte coverage and method detection limits to other pesticide methods currently used nationally by USGS programs. Additionally, DuPont will be able to (1) fill a gap in data regarding 

the environmental occurrence of SU herbicides, (2) support research comparing the environmental occurrence of SUs with that of other herbicides, and (3) promote environmental stewardship in the use of their 

products.

C

Figure 1. Estimated acres of corn, soybeans, or wheat 

treated with selected sulfonylurea, sulfonamide, and 

imidazolinone herbicides, 1990-96, in midwestern States.

BACKGROUND

Over the last 20 years, a generation of low application rate herbicides have been developed that act by 

inhibiting the action of a key plant enzyme, resulting in 

stopped growth and eventual plant death. The enzyme 

that these herbicides act upon is specific to plants and 

they are reported to have very low toxicities in mammals 

or other animals (Brown, 1990; Meister, 1997). SU, SA, 

and IMI herbicides are three compound classes that act in 

this manner. Crops that can be treated with SUs, SAs, 

and IMIs include barley, corn, cotton, durum wheat, peanuts, rice, soybeans, sugar beets, canola, spring wheat, 

and winter wheat. These herbicides are gaining in popularity among farmers. The total corn, soybean, and wheat 

acreage on which 9 SUs, 1 SA and 2 IMIs were applied 

in eleven midwestern States (Iowa, Illinois, Indiana, 

Kansas, Kentucky, Minnesota, Missouri, Nebraska, Ohio, 

South Dakota, and Wisconsin) from 1990 through 1996 

is shown in figure 1 (U.S. Department of Agriculture, 

1991–97). In 1996, the area treated exceeded 59 million 

acres. For comparison, atrazine, a triazine herbicide, was 

used on 44.2 million acres of corn in the same 11-State 

area, in 1996. Although applied over comparable areas, 

SU, SA, and IMI herbicides typically are applied at much 

lower rates than other commonly used herbicides classes. 

For example, in 1996, in the same 11-State midwestern 

area, an estimated 23,200 tons of atrazine and 19,360 

tons of metolachlor were applied to cropland, while the 

estimated use of 9 SUs, 1 SA, and 2 IMIs was only 1,150 

tons (U.S. Department of Agriculture, 1997).

Plants demonstrate a wide range in sensitivity to 

SUs, SAs, and IMIs with over a 1000-fold difference in 

observed toxicity levels for some compounds. The concentration in water in the soil zone is the toxicologically 

A Reconnaissance for Sulfonylurea Herbicides in Waters of 

the Midwestern USA: An Example of Collaboration 

Between the Public and Private Sectors
contract for procured services regulated by Federal 

Acquisition Regulations, a CRADA between Federal and 

private sector partners is a type of noncompetitive agreement. More details about CRADAs can be found on the 

USGS Technology Transfer homepage (see 

http://www.usgs.gov/tech-transfer/index.html). 

SPECIFICS ABOUT THE USGS-DUPONT CRADA

The CRADA between the USGS and DuPont consists of general provision (10 pages), and a statement of 

work (approximately 12 pages). Development, review, 

and approval of the CRADA by both parties took about 6 

months. While CRADA use in some Federal agencies 

such as the U.S. Environmental Protection Agency has 

been extensive, the CRADA 

between the Water Resources 

Division of the USGS and 

DuPont is one of the first to 

be developed between the 

USGS and a non-federal partner. The overall objective of 

the CRADA is to begin developing an understanding of the 

occurrence of selected SUs, 

SAs, and IMIs in water 

resources of the midwestern 

United States. 

The CRADA outlines 

tasks and products that are 

expected from both parties. 

The tasks listed as DuPont’s 

responsibilities under the 

CRADA include (1) providing the USGS National Water 

Quality Laboratory (NWQL) 

with the written materials and 

guidance needed to develop and validate an analytical 

method for detecting selected SUs, SAs, and IMIs in 

water samples at a quantification limit of 0.1 μg/L, 

(2) providing technical consultation to the NWQL on 

analytical methods adaptation and development, and 

(3) providing data on the physical and chemical properties and toxicity of SUs and their degradation products. 

The tasks listed as USGS responsibilities include 

(1) developing and executing a work plan for the first 

year of the project focusing on sample collection (with 

samples going to a laboratory chosen by DuPont) and 

analytical methods development, (2) validating the performance of the analytical method provided by DuPont 

as part of an Association of Official Analytical Chemists 

(AOAC) method validation process, (3) modifying the 

DuPont method, if feasible, to improve sensitivity to a 

 

Table 1. Common names, chemical classes, trade names, and crops treated 

for target analytes

Common name Class Trade names1 Crops treated

bensulfuron methyl sulfonylurea Londax rice

chlorimuron ethyl sulfonylurea Classic, Canopy, Reliance soybeans, peanuts

chlorsulfuron sulfonylurea Glean, Telar, Finesse grains, non-crop land

flumetsulam sulfonamide Broadstrike, Preside, Scorpion corn, soybeans

halosulfuron methyl sulfonylurea Battalion, Manage, Permit corn, sorghum, turf

imazapyr imidazolinone Arsenal, Chopper noncropland

imazaquin imidazolinone Scepter, Detail soybeans

imazethapyr imidazolinone Pursuit soybeans, corn

metsulfuron methyl sulfonylurea Allie, Ally, Escort grains, pasture, noncrop

nicosulfuron sulfonylurea Accent corn

primisulfuron methyl sulfonylurea Beacon, Tell corn

prosulfuron sulfonylurea Peak corn, sorghum, grains

sulfometuron methyl sulfonylurea Oust trees, noncrop, turf

thifensulfuron methyl sulfonylurea Pinnacle, Reliance soybeans, grains, corn

triasulfuron sulfonylurea Amber, Longran grain, fallow

triflusulfuron methyl sulfonylurea Upbeet sugarbeets

1Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not 

imply endorsement by the U.S. Government.

WHAT IS A CRADA?

Cooperative Research and Development Agreements 

or CRADAs were created by the Federal Technology 

Transfer Act of 1986. The Act permits CRADAs to be 

developed by Federal agencies to encourage collaboration 

with non-Federal parties. CRADAs enable both partners to 

share intellectual material, protect information, and leverage their research budgets to optimize results. The non-federal partner can provide services, personnel, equipment, or 

funds in order to accomplish the goals of the CRADA. The 

Federal partner can provide similar resources but not funds 

directly to the partner. CRADAs typically consist of two 

components: general provisions (the legal framework) and 

a statement of work (the objectives, tasks, and deliverables 

of the CRADA activity). A CRADA is a legal contract 

forming a business agreement. Unlike the typical 

relevant concentration. Because SUs, SAs, and IMIs are 

active at very low concentrations they can cause a problem with plant vigor in some crop rotations even when 

only 1 percent or less of the originally applied material 

remains. Little non-target crop stress is expected from 

soil water concentrations below 0.1 μg/L (micrograms 

per liter, or part per billion). Less is known about the 

effect of these compounds on noncrop plant species, but 

a concentration of 1.0 μg/L in water appears to be a 

threshold for possible native aquatic plant toxicity (U.S. 

Environmental Protection Agency, Office of Pesticide 

Programs, Environmental Fate and Effects Division, Tox 

One-Liner Database, written commun., 1997).
point were it is comparable with the sensitivity of other 

analytical methods currently offered by the NWQL for 

other classes of pesticides and to include other labile pesticide parent compounds and degradation products of 

SUs, SAs, and IMIs, (4) developing a work plan for 1998 

focusing on a multi-state intensive reconnaissance to 

determine the frequency and magnitude of SU, SA, and 

IMI detections in water samples, and (5) publishing 

reports that interpret the results from samples collected 

and analyzed by the USGS in 1998.

The CRADA also outlines any constraints or limitations that are placed on the information exchanged, 

results obtained, or data generated by the CRADA activity. The subject CRADA specifies that the USGS and 

DuPont will be allowed to freely publish the results of 

this study within the limitations of section 7.4.2 (a section of the General Provisions). This section states that 

the USGS and DuPont agree to confer and consult at 

least 30 days prior to either party’s submission for publication of subject data. The CRADA also states that the 

USGS and DuPont will be allowed to review and comment upon, but not censor any data, interpretations, or 

reports resulting from the CRADA activity. For publication purposes, data generated from samples analyzed by 

the NWQL will be reported as USGS data and data generated by analyses by DuPont or by any laboratory 

selected by Dupont will not be reported as USGS data.

External oversight and technical review of analytical 

methods development, work plan development, study 

design, and data interpretations are provided by the Interagency Method and Data Comparability Board (MDCB). 

The MDCB and the National Water-Quality Monitoring 

Council (NWQMC) were chartered in 1997 under the 

Federal Advisory Committee Act. The Council’s charge 

is to implement a nationwide strategy to improve waterquality monitoring, assessment, and reporting, and to 

oversee activities of the MDCB. The Board’s charge is to 

identify, examine, and recommend monitoring 

approaches that facilitate collaboration and yield comparable data and assessment results. Board members come 

from Federal, State, tribal, and private organizations and 

have a mix of interests and expertise. Oversight by the 

MDCB of the activities associated with this CRADA provides an external review by a group with diverse 

perspectives. 

The USGS will commit time and personnel for work 

plan development, analytical methods development, sample collection, sample analysis, data interpretation, and 

reports preparation. DuPont will commit time and personnel for analytical methods development support, sample analysis, reviews of work plans, and reviews of data 

interpretations. DuPont will also commit financial support for sample collection and analysis, for a portion of 

analytical methods development, and for some costs 

associated with the external oversight (travel and meeting 

costs). 

PROJECT STATUS

Analytical Methods

A multianalyte water method developed by DuPont 

is one of five methods developed in association with the 

EPA/Industry Multianalyte Methods (MAM) group. The 

DuPont method (Rodriguez and Orescan, 1996) uses 

electrospray HPLC/MS (high performance liquid chromatography coupled with mass spectrometry) to detect 

16 SUs, SAs, and IMIs (table 1) with a limit of quantitation of 0.1 μg/L for all analytes. NWQL Methods Development staff have started on an Association of Official 

Analytical Chemists (AOAC) validation for the DuPont 

method. Further method development work has also 

started. The goal is to modify the DuPont method, to 

improve sensitivity to a point were it is comparable with 

the sensitivity of methods for other classes of pesticides 

(method reporting limits range from 0.001 to 0.05 μg/L). 

The NWQL has targeted several activities that are 

expected to help improve the sensitivity of this method. 

These include (1) switching from external standard quantitation to internal standard quantitation, (2) increasing 

the sample size for extraction from 250 milliliters to 

1 liter, (3) comparing a range of extraction media, and 

(4) expanding the range of analytes to include additional 

SU, SA, and IMI herbicides and herbicide metabolites.

Figure 2. Location of surface-water and ground-water 

sites sampled in 1997.
Fact Sheet FS- –98 046

Sample Collection

The first phase of CRADA sampling activity was 

initiated in summer and fall 1997. Approximately 50 

samples were collected by USGS personnel from 40 sites 

(20 streams and 20 wells) (fig. 2). These samples were 

sent to researchers at the National Soil Tilth Laboratory 

(chosen by DuPont) for analysis. Sampling activities in 

1998 will focus in the areas of highest herbicide use 

(fig. 3). The 1998 study plan calls for the collection of 

150–200 samples from 100 sites. These samples will be 

analyzed at the NWQL using both the DuPont method 

and the modified method for at least the 16 analytes listed 

in table 1 plus any additional herbicides or herbicide degradation products added to the target analytes list by the 

method modifications. Water from all or selected samples 

collected in 1998 will be sent to DuPont for confirmatory 

analysis. Water from all samples collected in 1998 will 

also be analyzed for selected other pesticides. Where 

possible, samples will be collected in conjunction with 

planned USGS activities in order to reduce sample collection costs.

Expected Results

The expected outcome of the activities associated 

with this CRADA will be a better understanding the 

occurrence of selected SU, SA, and IMI herbicides in 

water resources of the midwestern United States. Specific 

results will include AOAC validation of DuPont’s multianalyte water method for selected SUs, SAs, IMIs and 

development of a modified method with improved sensitivity. Analytical results and interpretations from water 

samples collected and analyzed by the USGS in a 1998 

will be published. This CRADA is also expected to serve 

as an example of how cooperative projects with the 

USGS and private industry enables leveraging of budgets 

and optimization of results while maintaining an impartial scientific approach to addressing nationally relevant 

earth science questions. 

—By William A. Battaglin, Edward T. Furlong, and 

C. John Peter

REFERENCES

Brown, H.M., 1990, Mode of action, crop selectivity, and 

soil relations of the sulfonylurea herbicides: Pesticide Science. vol. 29, p. 263–281.

Meister, R.T., 1997, Farm chemicals handbook’97: 

Willoughby, Ohio, Meister Publishing. 

Rodriguez, M. and Orescan, D.B., 1996, Analytical 

method for the quantitation and confirmation of 

selected sulfonylurea, imidazolinone, and sulfonamide herbicides in surface water using electrospray 

LC/MS: DuPont Report No. AMR 4118–96.

U.S. Department of Agriculture, 1991–1997, Agricultural 

chemical usage—1990–1996 field crops summary: 

Washington, D.C., USDA, National Agricultural 

Statistics Service, (published annually).

For further information, contact:

William A. Battaglin

U.S. Geological Survey

Box 25046, MS 406, Denver Federal Center

Denver, CO 80225

April 1998

Figure 3. Estimated 1992 county-level use of (a) 

imazethapyr and (b) nicosulfuron.