JPS5899756A - Measurement of biological concentration of chemical substance employing aquatic animal - Google Patents

Abstract

PURPOSE:To enable the measurement of biological concentration of chemical compounds for such a short time as only a few days by determinig the intake speed and the excretion speed of the chemical compound when it is orally dosed to an aquatic animal once. CONSTITUTION:A test tank with a capacity of 120l is kept at the temperature of 25 deg.C. Twenty carps are put in the tank and made inured to the environment for 2 weeks. Then, they are dosed with a feed containing chemical compounds as listed at a rate of 1% of the weight per fish. The feed is 20% in the water content with a diameter of 3mm. and a length of 3mm.. Then, five each of the carps are sampled at a specified time interval and undergo an analysis as a whole after the removal of intestinal tracts thereof. From the results of the analysis, a graph is obtained which indicates a relationship of logarithmic values of the concentrations of the chemical compounds in the carps to the time passed after the dosage of the compounds. Based on the graph, the constant of the intake speed and the constant of the excretion speed are determined for each chemical compound and further, the ratio of both the speed constants is calculated.

Description

[Detailed Description of the Invention] The present invention enables the concentration level to be measured in a short time by administering a chemical substance orally to aquatic organisms and measuring its uptake rate and excretion rate. The present invention also relates to a method for measuring bioconcentration of chemical substances, which can also be applied to compounds that are insoluble or poorly dispersible in water.

In recent years, with the rapid development of the chemical industry, the influence of chemical substances on the human body and the environment has become a major issue. The concentration of chemicals in aquatic organisms has been measured. This concentration measurement method is based on the fact that aqueous solutions of chemicals, substances, etc. with different concentrations are constantly flowing into multiple test tanks; aquatic organisms are kept in these test waters and tanks for a long period of time (usually two months). This method concentrates chemicals in aquatic organisms primarily through the gills, regardless of the oral method.
The purpose of the present invention is to provide a method for measuring bioconcentration of chemical substances using aquatic organisms, which can be applied to sexually active chemical substances, and requires only a few days to measure the concentration.

゛ That is, the present invention provides a bioconcentration measurement method for measuring the concentration of a chemical substance in an aquatic organism by administering a chemical substance to an aquatic organism, in which the chemical substance is administered once to the aquatic organism by an oral administration method, After administration, the amount of the chemical substance taken into the aquatic organisms is measured over time, and the uptake rate constant and excretion rate constant are calculated from the measured value of t. From the values of these two constants, it is possible to determine the effect of the chemical substance on aquatic organisms. This is to find the degree of concentration.

As the aquatic organisms used in the present invention, aquatic organisms that live in freshwater such as carp, crucian carp, tilapia, and trout, and aquatic organisms that live in seawater such as sea bream can be used.

Carp is particularly preferred because of its ease of availability and ease of handling. Because these aquatic organisms are selected and used during a certain growth period, the data variation is 2y &: small・t 10
fi, and those with a weight of about 20 to 409 are preferably used.

As a test tank, an ordinary glass box plastic water tank can be used as appropriate, but a new tank is used to prevent chemical substances from uneaten food from leaching into the tank water and being absorbed by aquatic organisms. A running water test tank with constant water supply is easy to use. The inflowing breeding water must be temperature controlled, contain sufficient dissolved IIX, and be substantially free of harmful components.

According to the present invention, a known amount of a chemical substance is orally administered only once to aquatic organisms prepared in the test tank or the like. It is preferable that the chemical substance is usually mixed with the bait and molded into a shape. For example, when using fish with an average weight of 20 to 30 degrees for the test, the chemical substance is mixed with the bait and the diameter of the bait is 1 to 1.
It is desirable to form it into a size with a length of 3 to 5 inches. Feed containing chemical substances formed in this way is generally used to measure the amount of chemical substances, but the number of measurements is based on the uptake rate constant, excretion rate constant, and measurement of chemical substances.
times/day. The measurement period is usually approximately 4 hours, which is the time required for the concentration of the chemical in aquatic organisms to reach its maximum after administration of the chemical.
It is sufficient to double the total measurement period, and although this period varies somewhat depending on the chemical substance, it is generally within Fi 24 hours.

As a method for measuring the concentration of chemical substances in aquatic organisms, an appropriate analytical method can be selected. When analyzing the entire body of an aquatic organism, it may be necessary to remove the intestinal tract in advance, in which unincorporated chemical substances may remain in the aquatic organism's body, and prepare the aquatic organism for analysis.

In the present invention, the uptake rate constant aKi and the excretion rate constant ~ are determined from the relationship between the amount (concentration) of the chemical substance taken into aquatic organisms and time determined in this way. Expanded formula (1) for both of these constants, (214E Excretion rate constant C of a chemical substance in aquatic organisms; Concentration D of a chemical substance in aquatic organisms D: Amount of a chemical substance with zero absorption capacity remaining in the digestive tract of an aquatic organism. Although it is defined, it is convenient to use the drawing method to find the value of 1tK.

That is, the first diagram is created using a drawing method using a graph showing the relationship between the elapsed time after a single administration of a chemical substance to an aquatic organism and the measured concentration of the chemical substance in the aquatic organism. This shows an example of finding Kl. Curve P in this graph is a concentration curve of chemical substances in aquatic organisms obtained through actual measurements.In this curve P, 1.
The period leading up to tl is an increasing period in which the concentration of chemical substances in aquatic organisms increases, and after tl there is a decreasing period in which it decreases with the passage of time. The curve ptt in this decreasing period
-=to, = 0.639/t34 -...
・(3)-4, Ai calculates the difference between the value of the extrapolation line Q or the value of the song mp in the increasing period (t=o-t,), plots this on the graph, and calculates these It can be determined graphically as the slope of the straight line R connecting the first point to the next point.

From the 9 uptake rate constants obtained in this way and the excretion rate constant 4, the rate constant ratio K expressed by the following formula (4) is determined. It is recognized that there is an extremely high correlation with the numerical value.

Therefore, using a graph showing the relationship between the value of K determined in advance by experiment and the logarithm value of the concentration Cf, the concentration Cf can be calculated from the value of 7'cK determined by a single administration of an arbitrary chemical substance. Concentration [Cf] is determined by reading.

This is convenient when it is necessary to determine the approximate concentration of a substance in a short time. However, the measurement accuracy when using the method of the present invention is high. Furthermore, according to this method, chemical substances are administered orally, so even chemical substances that are difficult to disperse or dissolve in water as in conventional methods can be easily tested. Moreover, it has the advantage that the test equipment is simple.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

〔Example〕

mll! The rate constant ratio of each compound was determined by the method of the present invention using carp as a living organism.

Table 1: A test tank with a volume of 1,201 cm was set at a temperature of 25, and 20 carp were placed in it and left in the environment for 2 weeks.
Contains chemicals diameter 3 iua, length -, moisture content 20
91 feed was fed in an amount equal to 1 of the fish body weight.Then, 5 fish each were stripped at predetermined time intervals, and the entire fish was subjected to analysis with the intestinal tract removed. From the results of this analysis, a graph showing the relationship between the logarithm of the chemical concentration in the carp and the elapsed time after administration was obtained. From this graph, the uptake rate constant increase and excretion rate constant of each chemical substance were determined by the plotting method, and the rate constant ratio K was also determined, and the results are shown in Table i2. For comparison, the concentration of determined by the conventional method is also shown.

K like this and get 7'? 1. FIG. 2 shows the relationship between the value of C and the concentration Cf determined by the conventional method. in this case,
The correlation was extremely good with an r of 0.99.

[Brief explanation of the drawing]

1. Figure 1 shows the extrapolation lines used to calculate the uptake rate constant Km and the removal rate constant ~. *6 Logarithm of chemical concentration in living organisms and elapsed time after administration. Figure 2 is a graph showing the relationship between jog '; and Figure 2.
It is a graph showing the relationship between f and rate constant ratio. Wkenzsh Technological Techniques Lee Tl Inn Sekiban Makoto. Elapsed time after administration (1) Figure 2 Uptake rate constant (K t ) /! J xingren degree constant (K2
) Procedures Amendment Written by Mr. Haruki Shimada, Commissioner of the Patent Office of Japan, April 1982 1. Indication of the case Patent Application No. 197700 of 1981 2. Title of the invention Bioconcentration of chemical substances using aquatic organisms Measurement - Method - & Person who makes corrections. Relationship to the incident, patent applicant 5-4Qo"a's,""m.57$3Ji3oB
. & correction pair i drawing

Claims (1)

[Scope of Claims] 1. In a bioconcentration measurement method in which a chemical substance is administered to an aquatic organism to maintain a constant concentration of the chemical substance in the aquatic organism, an RC chemical substance is administered once to an aquatic organism by a single oral administration method. , the uptake rate constant and excretion rate constant are determined from the measured values obtained by measuring the amount of the chemical substance taken into the aquatic organism body over time after administration, and the concentration of the chemical substance in the aquatic organism is determined from the value of this demarcation constant. A method for measuring bioconcentration of a chemical substance, characterized by determining the bioconcentration of a chemical substance. 2. The measuring method according to claim 1, wherein the aquatic organism is a freshwater fish.