Protocol for sampling and testing urine for 1080
Date: July 2019
1. Introduction
This sampling protocol has been prepared for general practitioners, pathology laboratories, Medical Officers of Health (MOH), and employers in the pest control industry who may be involved in the process of sampling industry workers to assess the possibility of recent exposure to 1080. It provides information on sampling, handling, transport, contact names, and the costs involved. Samples are received and analysed by the Toxicology Laboratory at Manaaki Whenua – Landcare Research, Lincoln.
Sodium monofluoroacetate (Compound 1080) is a highly water-soluble vertebrate pesticide, used in the control of possums and rabbits. Pest control operations using 1080, particularly the aerial distribution of 1080 baits, are closely monitored by Medical Officers of Health, and in some cases it may be specified that samples from waterways close to operational areas are tested for 1080 (see the Guideline for Sampling and Testing Water Associated with Monitoring of Aerial 1080 Baiting Operations (4th edition) Booth 2019).
Employers in the pest control industry are encouraged to undertake the routine (at least annual) monitoring of workers who handle material containing 1080. In the context of occupational exposure to 1080, the Occupational Safety and Health Service (OSH), Department of Labour, has established a Biological Exposure Index (BEI) for 1080 in urine, which has been set at 0.015 µg/mL (ppm). More information about the BEI can be found at: http://www.osh.dol.govt.nz/order/catalogue/pdf/wes2002.pdf.
Urine testing is the preferred method for measuring worker exposure to 1080 as the BEI is based on urine sampling. But blood testing can be used in situations where urine sampling is not appropriate – for example, in cases where a blood test is specifically requested, or when a urine sample cannot be taken in a manner that excludes the possibility of contamination with 1080. (See Protocol for Sampling and Testing Blood Plasma for 1080 – Booth 2019).
2. Sampling
Urine samples should be taken in a clean environment free from any possibility of sample contamination with 1080. Ideally the sample should be taken after the worker has removed work clothes, showered and dressed in clean clothes. If this is not practical, the person giving the sample should at least remove protective gear or outer clothing and wash his/her hands thoroughly beforehand.
Where the sample is being taken to monitor exposure of pest control industry workers, at least one sample per individual should be taken within 2 hours of finishing a shift. Worker samples should be taken well away from areas where 1080 products are handled, transported or stored.
The sample is to be taken into a clean, disposable cup and transferred to a 70-mL specimen container (pink-topped, non-sterile is suitable). A minimum sample of 40 mL is required as samples may need to be analysed in duplicate to confirm the result. The samples should be kept chilled (~5°C), awaiting transport, and should be frozen (-10°C) if they are to be stored longer than 1 day.
3. Sample integrity
The limit of detection for the testing method is some 1,500,000 times lower than the typical concentration in possum baits (the method limit of detection is 1 part per billion (ppb) for urine samples). Hence the method for testing the sample is extremely sensitive and even minute amounts of 1080 may be detected. Sample containers must not, therefore, become contaminated in any way, even externally.
4. Sample labelling
Samples must be labelled to uniquely identify them, and this should include the date and time that the sample was taken. This information will be used to identify samples on the laboratory report. The laboratory report is confidential and will be disclosed to the submitting laboratory or the patient only, unless appropriate written permission is given. A sample form is included on the last page of this protocol and may be photocopied as required. It must accompany samples submitted to the laboratory for testing.
5. Transport requirements
Urine samples should be transported chilled (3 – 10°C), or frozen, to the testing laboratory within 2 days of taking the samples. This is best accomplished by including freezer packs with the sample set and packing in a polystyrene chilly bin.
Samples are to be sent to:
Laboratory Manager
Toxicology Laboratory
Manaaki Whenua - Landcare Research
54 Gerald Street
Lincoln, Canterbury 7608
Samples should be sent by courier door-to-door. No special declaration is required.
On receipt, the sample details will be entered in the laboratory sample register and the sample placed in a freezer at -20°C to await analysis, or, if urgent, analysed immediately.
6. Testing procedures
Samples will be entered on the laboratory work schedule and tested as soon as possible. Testing is usually completed within 7 working days (maximum 15 working days). The 24-hour service for critical samples requires the following:
- Warning of at least 1 day before sample arrival.
- Samples must be received at the laboratory by 10.30 a.m. on the day of testing.
- The service is available on a Friday only if a client representative will be available on Saturday to receive results.
- No more than 10 samples can be tested on a 24-hour basis.
Results will be available by 9.30 a.m. on the following day.
Testing is carried out using the gas chromatography method TLM 005, "Assay of 1080 in water, soil, and biological materials by GLC". This method was developed by Landcare Research, Lincoln, based on the work of Ozawa & Tsukioka (1987, 1989).
Urine samples are added directly to 2% sodium chloride solution and are then ready for derivatisation. The solution is acidified with hydrochloric acid and converted to the dichloroaniline derivative by using N,N'‑dicyclohexyl carbodiimide (DCC) and 2,4‑dichloroaniline (DCA). The derivative is cleaned on a silica solid-phase extraction cartridge, eluted with toluene, and quantified by gas chromatography with electron-capture detection. The limit of detection is 1 µg/L in a 10-mL urine sample.
An IANZ-endorsed laboratory report will be provided to the client on completion of the work.
7. Prices
The prices for testing for 1080 in urine samples as at 1 September 2008 are as follows:
| Standard rate | |
|---|---|
| 1–3 samples | $820 per sample |
| 4–6 samples | $628 per sample |
| >6 samples | $568 per sample |
These prices are exclusive of GST and are subject to change.
For a price for larger numbers of samples please contact the Laboratory Manager Phone 03 321 9617; Fax 03 321 9998.
8. References
Ozawa, H.; Tsukioka, T. 1987: Gas chromatographic determination of sodium monofluoroacetate in water by derivatization with dicyclohexylcarbodiimide. Analytical Chemistry 59: 2914–2917.
Ozawa, H.; Tsukioka, T. 1989: Determination of monofluoroacetate in soil and biological samples as the dichloroanilide derivative. Journal of Chromatography 473: 251–259.
Booth, L.H., Wright, G.R.G. 2008: Guideline for sampling and testing of water associated with monitoring of aerial 1080 baiting operations. Manaaki Whenua – Landcare Research, Lincoln.
Wright, G.R.G. 2002: Protocol for sampling and testing blood plasma for 1080. Manaaki Whenua – Landcare Research, Lincoln.