Standard substance for preparing seawater biochemical oxygen demand as well as preparation method and application of standard substance

Abstract

The invention relates to the field of environmental monitoring, in particular to a prepared seawater biochemical oxygen demand standard substance and a preparation method and application thereof. Pollution-free natural seawater is subjected to reverse osmosis and ion supplementation to prepare seawater which serves as a standard substance matrix, glucosamine hydrochloride serves as a single organic standard substance, and a segmented linear relation between a BOD5 biological reaction coefficient alpha (r) and a proportion r under different glucose / glutamic acid mass ratios is established. And deducing a conversion formula between the glucosamine hydrochloride and glucose + glutamic acid, determining the dosage of the glucosamine hydrochloride, dissolving the glucosamine hydrochloride in prepared seawater, adding a borax buffer agent, subpackaging, and carrying out heat sealing to obtain the standard substance for seawater BOD5 determination and quality control. The method solves the problems of low recovery rate, complicated configuration, lack of a unified conversion method and the like of the existing pure water matrix standard substance in seawater.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of environmental monitoring, and particularly relates to a kind of preparation of seawater biochemical oxygen demand standard substance and its preparation method and application. BACKGROUND

[0002] In recent years, the monitoring and management of marine pollution have attracted widespread attention, and the development of standard substances for quality control of marine environmental monitoring has also been valued. China has promulgated relevant seawater quality standards and marine monitoring specifications, but there is still a lack of seawater standard samples for seawater monitoring quality control, especially biochemical oxygen demand standard substances for seawater matrix. The existing biochemical oxygen demand standard solution is mostly a standard substance with pure water as the matrix and a mixture of glucose and glutamic acid as the organic substrate, and the recovery rate of the standard addition in seawater samples is not ideal, and there is a significant matrix effect.

[0003] In the prior art, the standard BOD5 solution is generally prepared by mixing and weighing dried glucose and glutamic acid, which has the problems of complicated preparation steps, low efficiency, and large human weighing and mixing errors. Moreover, when preparing the BOD5 standard substance with additional microbial nutrients, the preparation ratio of glucose and glutamic acid usually depends on empirical values, and there is a lack of clear theoretical calculation method. At the same time, the stability of the existing glucose + glutamic acid standard solution is limited, and it needs to be frozen at low temperature and has a short shelf life, which is inconvenient to use. SUMMARY

[0004] To solve the above technical problems, the present application provides a kind of preparation of seawater biochemical oxygen demand standard substance and its preparation method and application.

[0005] A preparation method of a seawater biochemical oxygen demand standard substance includes the following steps:

[0006] S1: Collecting natural seawater from a pollution-free sea area, filtering to remove particulate matter, and determining the composition and content of main inorganic ions such as sodium ions, calcium ions, magnesium ions, and chloride ions in the seawater; filtering the natural seawater to obtain reverse osmosis water; then adding sodium chloride, calcium chloride, and magnesium sulfate to the reverse osmosis water to dissolve according to the composition and proportion of sodium ions, calcium ions, magnesium ions, and chloride ions in the natural seawater, and adjusting the pH to 7.5-8 to simulate the composition of natural seawater, to obtain an artificially prepared seawater matrix;

[0007] S2: Placing the seawater prepared in S1 into a glass bottle, sterilizing at high temperature, and sealing for storage.

[0008] S3: According to the reaction equation of amino-glucose consumed by oxidation reaction and the theoretical oxygen consumption of microbial growth, combined with the target biochemical oxygen demand BOD5 value and the simulation of microbial survival environment parameters, the mass M of the added nutrient substance amino-glucose hydrochloride is determinedA ;

[0009] S4: weighing the amount of glucosamine hydrochloride determined in step S3 A , dissolving it in the artificial prepared seawater obtained in step S2, fully stirring to mix it, and adjusting the pH of the solution to 6.5-7.5;

[0010] S5: adding solid borax and boric acid to the solution obtained in step S4 to maintain the pH stability of the solution;

[0011] S6: using a peristaltic pump to divide the solution prepared in step S5 into glass ampoules, 100 mL per ampoule, and then immediately packaging it with an automatic fusion sealing machine to obtain the seawater biochemical oxygen demand standard substance.

[0012] Further, the natural seawater in step S1 is nearshore or near-surface seawater far from pollution sources, the specific method of filtration is to remove particulate matter in seawater by using a 0.45 μm fiber filter membrane, the purity of sodium chloride, calcium chloride and magnesium sulfate is analytical pure, and the pH is adjusted to 7.5-8 with 1M sodium hydroxide.

[0013] Further, the steps of step S3 are as follows:

[0014] (1) According to the complete oxidation reaction of glucose and glutamic acid, under the condition that 150 mg of glucose and 150 mg of glutamic acid completely react in 1 L of water to correspond to BOD5 of about 340 mg / L, the stoichiometric relationship of glucosamine is 179 g of substance consuming 192 g of oxygen, and thus the amount of glucosamine is 317 mg / L and the amount of glucosamine hydrochloride is 382 mg / L when the corresponding BOD5 is 340 mg / L;

[0015] (2) Under the BOD5 determination condition, different amounts of glucose M P and glutamic acid M G are added to distilled water, respectively, then M BOD5 = α (r) * (192 / 180M P + 352 / 294M G ), wherein r = M P / M G , and α (r) is the national standard five-day biological reaction coefficient of glucose and glutamic acid;

[0016] (3) Similarly, under the BOD5 determination condition, different amounts of glucosamine hydrochloride M A are added to distilled water, then the conversion method of different adding proportions of glucose and glutamic acid is 192 / 179*317 / 382*M A *α A= alpha(r)*(192 / 180M P + 352 / 294M G ), wherein alpha A is the national standard five-day biological reaction coefficient of glucosamine hydrochloride;

[0017] (4) so the glucosamine hydrochloride dosage calculation formula is:

[0018] M A = alpha(r) / alpha A *(192 / 180M P + 352 / 294M G )*179 / 192*382 / 317.

[0019] Further, the alpha(r) satisfies the following piecewise linear relationship between r in the range of 0.5<=r<=2:

[0020] Further, the alpha A =0.60-0.64.

[0021] Further, the step S4 adjusts the pH to 6.5-7.5 by 1M sodium hydroxide.

[0022] Further, in the step S5, the borax and boric acid are both analytical pure, and the addition amount of the borax and boric acid is 1.4-1.7g / L and 8.4-8.7g / L respectively, and the solution pH is maintained to be stable at 7.0.

[0023] The application further protects that the seawater biochemical oxygen demand standard substance prepared by the preparation method is configured by using glucosamine hydrochloride instead of glucose and glutamic acid.

[0024] The application further protects the application of the seawater biochemical oxygen demand standard substance, and the seawater biochemical oxygen demand standard substance is used for the standard recovery test and indoor quality control of seawater BOD5 determination.

[0025] Beneficial effects

[0026] 1. The seawater BOD5 standard substance conversion method is first proposed: through systematic research on the oxygen consumption kinetics of microorganisms under different glucose / glutamic acid mass ratios, the piecewise linear relationship between the biological reaction coefficient alpha(r) and r is established, and the unified calculation formula of the BOD5 theoretical value is given, so that the quantitative correlation between the standard substance composition and the BOD5 value is realized.

[0027] 2. The amino glucose hydrochloride replacement method is proposed: amino glucose hydrochloride is used as a single organic nutrient that provides carbon source and nitrogen source, and the conversion relationship between it and the glucose+glutamic acid mixture is established, which simplifies the configuration process and maintains or improves the accuracy of BOD5 representation.

[0028] 3. Simple configuration and small operation error: the present application only needs to weigh amino glucose hydrochloride once, and the dosage can be determined by calculation, which greatly reduces the human error introduced by multiple weighing and mixing operations, and improves the repeatability and traceability of the preparation of standard substances.

[0029] 4. The method of the present application is not only suitable for the quality control of BOD5 determination of seawater samples, but also can provide theoretical and methodological support for the development of BOD5 standard substances for other salt-containing water bodies or special substrates.

[0030] 5. The standard substance has good medium and long-term stability, and is more suitable for daily quality control than the existing glucose+glutamic acid standard solution which requires preparation on demand. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the present application clearer and more apparent, the present application will be further described in detail below in combination with specific test examples and embodiments.

[0032] Let the glucose dosage be M P , and the glutamic acid dosage be M G , and r=M P / M G， Let the BOD5 reaction consumption be M BOD5 , and the national standard five-day biological reaction coefficient be α (r). In BOD5 determination, if the glutamic acid or glucose in the standard substance is greatly reduced, the degradation substrate composition and oxygen consumption mode of microorganisms will be changed, which may cause the BOD5 determination value to deviate from the expected value, and seriously affect the accuracy and comparability of the determination result. Therefore, the simulated environment with a large amount of adjustment of the composition of the standard verification substance does not have accuracy and representativeness, for example, M P / M G >2, M P / M G <1 / 2, etc., are not selected.

[0033] According to the national standard and the chemical reaction equation,

[0034] ① Glucose C6H 12 O6+6O2→6CO2+6H2O+△E

[0035] ② Glutamic acid 2C5H9NO4+11O2→2NH3+6H2O+10CO2+△E

[0036] MBOD5 = a(r) * (192 / 180M P + 352 / 294M G ).

[0037] Test Example 1

[0038] When M P / M G = 1 / 2, at this time, the survival environment of general microorganisms with more nitrogen source and less carbon source is simulated, and the oxygen consumption dynamics will change: the rate and mode of microorganism degradation of more nitrogen source substances may be different from the degradation of equal mixed organic matter (sugar + amino acid). The glutamic acid in the original mixed solution increases, and this part of ammonia nitrogen may be further oxidized in a long enough culture time or in the presence of specific microorganisms, i.e. nitrification occurs. The nitrification process is an oxygen consumption process, which will consume additional dissolved oxygen. This makes the total oxygen consumption no longer only reflect the oxidation of organic carbon, but also may contain the oxidation of nitrogen-containing substances, resulting in the measured BOD5 value may be higher than the oxygen consumption of pure oxidation of organic carbon. That is, in 1L distilled water, the complete reaction BOD5 is 340mg, then according to reaction equations ① and ②, take 98mg glucose and 197mg glutamic acid, and add 10ml standard microbial seed. The standard microbial seed is the inoculum for inoculating microorganisms according to the requirements of the national environmental protection standard HJ 505-2009. The BOD5 value is measured by the national standard five-day culture method as shown in Table 1:

[0039] Table 1

[0040] No. BOD5 (mg / L) No. BOD5 (mg / L) 1 234.7 6 249.8 2 245.1 7 251.6 3 224.4 8 234.9 4 258.4 9 228.4 5 230.1 10 243.9

[0041] According to Table 1, the five-day biological reaction coefficient is a(1 / 2)=0.66-0.76.

[0042] Test Example 2

[0043] When M P / M G = 2 / 3, at this time, the survival environment of general microorganisms with more nitrogen source and less carbon source is also simulated, i.e. in 1L distilled water, the complete reaction BOD5 is still 340mg, then according to reaction equations ① and ②, take 119mg glucose and 178mg glutamic acid, and add 10ml standard microbial seed, and the BOD5 value is measured by the national standard five-day culture method as shown in Table 2:

[0044] Table 2

[0045] No. BOD5 (mg / L) No. BOD5 (mg / L) 1 210.5 6 230.9 2 222.4 7 244.8 3 235.1 8 214.9 4 204.0 9 228.4 5 215.6 10 206.9

[0046] According to the experimental data, the five-day biological reaction coefficient is a(2 / 3)=0.60-0.72.

[0047] When M P / M G =1, according to the People's Republic of China national environmental protection standard HJ 505-2009 "water quality five-day biochemical oxygen demand (BOD5) determination dilution and inoculation method" in the method BOD5 theoretical value is 190-230mg, then five days biological reaction coefficient α (1) =0.56-0.68.

[0048] Test Example 3

[0049] When 2≥M P / M G =1, at this time, the simulation is the survival environment of general microorganism with more carbon source and less nitrogen source, its oxygen consumption dynamics will change: the rate and mode of microorganism degrading more sugar substances may be different from degrading equivalent mixed organic matter. And there is potential nitrification inhibition: the decrease of glutamic acid in the original mixed solution may introduce insufficient amount of nitrogen source, which may affect the metabolic efficiency of microorganism on carbon source, thereby indirectly reducing oxygen consumption.

[0050] When M P / M G =1.5, that is, in 1L distilled water, according to reaction equations ① and ②, take 182mg glucose and 121mg glutamic acid, and add 10ml standard microbial seed. The BOD5 value determined according to the national standard five-day culture method is shown in Table Three:

[0051] Table Three

[0052] No. BOD5 (mg / L) No. BOD5 (mg / L) 1 183.2 6 221.0 2 189.2 7 209.4 3 176.8 8 179.2 4 216.6 9 188.2 5 195.5 10 206.9

[0053] According to the experimental data, its five-day biological reaction coefficient is α (1.5) =0.52-0.65.

[0054] Test Example 4

[0055] When M P / M G =2, that is, in 1L distilled water, according to reaction equations ① and ②, take 204mg glucose and 102mg glutamic acid, and add 10ml standard microbial seed. The BOD5 value determined according to the national standard five-day culture method is shown in Table Four:

[0056] Table Four

[0057] No. BOD5 (mg / L) No. BOD5 (mg / L) 1 163.2 6 175.3 2 189.2 7 183.4 3 200.6 8 179.2 4 195.6 9 188.2 5 195.5 10 169.9

[0058] According to the experimental data, its five-day biological reaction coefficient is α (2) =0.48-0.59.

[0059] According to the experimental data, the biological reaction coefficient α (r) and the ratio of glucose and glutamic acid r=M P / M GThere is a negative correlation between them.

[0060] For 1 / 2≤r<1, using linear fitting from r=0.5 to r=1: the intercept is about -0.172, and the slope is 0.792. For 1≤r≤2, using linear fitting from r=1 to r=2: the intercept is about -0.079, and the slope is 0.699.

[0061] The function is continuous at r=1, and the value is 0.62.

[0062] Based on the experimental data points (r and the corresponding average value of a), a piecewise linear function formula is established, which is applicable to the range of 2≥r≥0.5. The function is continuous at r=1, and is in good agreement with the average value of the experimental data. The piecewise function formula of the biological reaction coefficient a and the ratio r:

[0063]

[0064] The oxidation reaction equation of glucosamine is:

[0065] C6H 13 NO5+6O2→NH3+5H2O+6CO2

[0066] Therefore, 179g of glucosamine corresponds to the consumption of 192g of oxygen. If glucosamine is used instead of glucose and glutamic acid as an organic substrate, when the amount of glucosamine used is 317mg in 1L of water, the theoretical BOD5 of complete reaction is about 340mg / L, and the amount of glucosamine hydrochloride used is 382mg. Therefore, in 1L of distilled water, take 382mg of glucosamine hydrochloride, add 10ml of standard microbial seed, and measure the BOD5 value according to the national standard five-day incubation method as shown in Table Five:

[0067] Table Five

[0068] No. BOD5 (mg / L) No. BOD5 (mg / L) No. BOD5 (mg / L) 1 191.1 8 198.9 15 202.4 2 203.4 9 202.4 16 194.3 3 193.1 10 193.9 17 197.4 4 201.9 11 210.7 18 220.1 5 195.5 12 140.2 19 154.6 6 203.4 13 199.6 20 200.2 7 200.4 14 192.3

[0069] The BOD5 range is about 197mg±6, and the biological reaction coefficient is 191 / 317-203 / 317=0.60-0.64, and the median value is a A =0.62.

[0070] Therefore, the calculation method of the amount of glucosamine hydrochloride is:

[0071] M A =α(r) / α A *(16 / 15M P +352 / 294M G )*179 / 192*382 / 317. Example

[0072] S1: Collect natural seawater from a pollution-free sea area, filter it through a 0.45 μm filter membrane, and then determine the composition and content of the main inorganic ions therein; perform reverse osmosis treatment on the filtered seawater to obtain reverse osmosis water; then, according to the composition and proportion of sodium ions, calcium ions, magnesium ions, chloride ions and the like in the natural seawater, add sodium chloride, calcium chloride and magnesium sulfate to the reverse osmosis water to dissolve, and add 1M sodium hydroxide solution to adjust the pH to 7.8 to simulate the composition of natural seawater, thereby obtaining an artificial seawater matrix.

[0073] S2: Place the seawater prepared in S1 into a glass bottle, sterilize it at high temperature, and then seal and store it.

[0074] S3: When the simulated M P = 140 mg / L and M G = 160 mg / L, r = 0.875, and 1 / 2 ≤ r < 1, the amount of glucosamine hydrochloride is:

[0075] M A = α(r) / α A *(192 / 180M P + 352 / 294M G )* 179 / 192* 382 / 317 = (0.792r - 0.172)*(192 / 180M P + 352 / 294M G )* 179 / 192* 382 / 317 = 321.82 mg / L.

[0076] S4: Weigh 321.82 mg of glucosamine hydrochloride, dissolve it in 0.8 L of the prepared seawater obtained in step S2, and stir until it is completely dissolved.

[0077] S5: Add 1M sodium hydroxide solution to the solution obtained in step S4 to adjust the pH to 6.5-7.5, then add 1.55 g of borax and 8.55 g of boric acid to maintain the pH of the solution at 7.0, and dilute it with prepared seawater to a constant volume of 1 L.

[0078] S6: Use a peristaltic pump to divide the solution prepared in step S5 into glass ampoules, each containing 100 mL, and then immediately seal them with an automatic sealing machine to obtain a seawater biochemical oxygen demand standard substance.

[0079] Uniformity test of the prepared seawater biochemical oxygen demand standard substance.

[0080] According to the standard substance technical specification, 12 ampoules were randomly selected from the prepared seawater biochemical oxygen demand standard substance, and each ampoule was measured twice. The data of the uniformity test of the bottles and the inter-bottle uniformity test were statistically analyzed by single factor variance analysis method, as shown in Table 6. The data in Table 6 were analyzed by uniformity test, and the results were as follows: a total of 12 samples were analyzed, each sample was measured twice, the measurement value range was 198.3-204.9 mg / L, the average value was 201.0 mg / L, the standard deviation was 1.7 mg / L, and the coefficient of variation was 0.86%. The F test result showed that there was no significant difference between the samples (F = 0.94, p = 0.53638), the difference of repeated measurement was within the acceptable range, the average value of the difference of two measurements was -0.61 mg / L, the maximum absolute difference was 6.4 mg / L, and the maximum relative difference was 3.18%. According to the F test result (p>0.05), there was no significant difference between the samples, which indicated that the samples in this batch were uniform in measurement characteristics. The difference of repeated measurement was within the acceptable range, which indicated that the measurement system had good precision.

[0081] Table 6 Uniformity test measurement data of chemical oxygen demand standard substance in natural seawater

[0082] Stability test of chemical oxygen demand standard substance in natural seawater

[0083] The prepared seawater biochemical oxygen demand standard substance was stored under the specified conditions, and the stability was monitored according to the principle of first tight and then loose. The stability data of 6 months is shown in Table 7.

[0084] The BOD5 measurement data of 4 time points were detected, and each time point was measured twice. The measurement value range was 191.4-199.4 mg / L, the average value was 196.4 mg / L, the standard deviation was 3.5 mg / L, and the relative standard deviation (RSD) was 1.77%. The linear trend analysis showed no significant time trend (R² = 0.0290, p = 0.8296). The consistency of repeated measurement was good, the maximum absolute change between adjacent time points was 8.0 mg / L, and the maximum relative change was 4.07%.

[0085] Table 7 Uniformity test measurement data of seawater chemical oxygen demand standard substance

[0086] In summary, the seawater biochemical oxygen demand standard substance tested in this test has good uniformity within the batch, excellent stability within 6 months under the specified storage conditions, and all indicators meet the requirements of the standard substance technical specification, and can be used as a reliable standard substance.

[0087] The above-described specific embodiments further specifically describe the technical problems solved by the present application, technical solutions and beneficial effects. It should be understood that the above-described specific embodiments are merely specific embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application. The specific embodiments are merely an explanation of the present application and are not intended to limit the present application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for the preparation of a certified seawater biochemical oxygen demand reference material, characterized in that, It comprises the following steps: S1: Collecting natural seawater from a non-polluted sea area, filtering to remove particulate matter, and determining the composition and content of main inorganic ions such as sodium ions, calcium ions, magnesium ions, and chloride ions in the seawater; filtering the natural seawater to obtain reverse osmosis water; then adding sodium chloride, calcium chloride, and magnesium sulfate to the reverse osmosis water according to the composition and proportion of sodium ions, calcium ions, magnesium ions, and chloride ions in the natural seawater, dissolving, and adjusting the pH to 7.5-8 to simulate the composition of natural seawater, thereby obtaining an artificial seawater matrix; S2: Placing the seawater prepared in S1 into a glass bottle, sterilizing at high temperature, and then sealing and storing; S3: According to the reaction equation of the oxidation reaction of glucosamine and the theoretical oxygen consumption of microbial growth, combined with the target biochemical oxygen demand BOD5 value and the simulation of the survival environment parameters of microorganisms, the mass M of the added nutrient substance glucosamine hydrochloride is determined A ; S4: Weigh the amount of glucosamine hydrochloride determined in step S3 A Dissolve it in the artificial seawater obtained in step S2, fully stir to mix it evenly, and adjust the pH of the solution to 6.5-7.5; S5: Adding solid boric acid and borax to the solution obtained in step S4 to maintain the pH stability of the solution; S6: Using a peristaltic pump to divide the solution prepared in step S5 into glass ampoules, each containing 100 mL, and then immediately packaging with an automatic fusion sealing machine to obtain seawater biochemical oxygen demand standard material.

2. The method for preparing a certified seawater biochemical oxygen demand reference material according to claim 1, characterized in that, The natural seawater in step S1 is near-shore or near-surface seawater far from pollution sources, the specific method of filtration is to remove particulate matter in seawater by using a 0.45 μm fiber filter membrane, and the purity of sodium chloride, calcium chloride, and magnesium sulfate is analytical pure, and the pH is adjusted to 7.5-8 with 1M sodium hydroxide.

3. The method for preparing a certified seawater biochemical oxygen demand reference material according to claim 1, characterized in that, The steps of step S3 are specifically: (1) According to the complete oxidation reaction of glucose and glutamic acid, 150 mg of glucose and 150 mg of glutamic acid are completely reacted in 1L of water, which corresponds to BOD5 of about 340 mg / L, and the stoichiometric relationship of aminoglucose is 179 g of substance consuming 192 g of oxygen, thereby obtaining the aminoglucose dosage of 317 mg / L and the aminoglucose hydrochloride dosage of 382 mg / L corresponding to BOD5 of 340 mg / L; (2) Under the condition of BOD5 determination, distilled water is added with different amounts of glucose M P and glutamic acid M G , then the BOD5 reaction consumption M BOD5 = α(r) * (192 / 180M P + 352 / 294M G ), where r = M P / M G , and α(r) is the national standard five-day biological reaction coefficient of glucose and glutamic acid; (3) Under the same BOD5 determination conditions, distilled water is added with different amounts of glucosamine hydrochloride M A , and the conversion method of glucose and glutamic acid with different adding proportions is 192 / 179*317 / 382*M A *α A =α(r)*(192 / 180M P +352 / 294M G ), where α A is the national five-day biological reaction coefficient of glucosamine hydrochloride; (4) Then the dosage calculation formula of aminoglucose hydrochloride is: M A =α(r) / α A *(192 / 180M P +352 / 294M G )*179 / 192*382 / 317.

4. The method for preparing a certified seawater biochemical oxygen demand reference material according to claim 3, characterized in that, The a(r) satisfies the following piecewise linear relationship between r in the range of 0.5≤r≤2:

5. The method for preparing a certified seawater biochemical oxygen demand reference material according to claim 3, characterized in that, The α A = 0.60-0.

64.

6. The method for preparing a certified seawater biochemical oxygen demand reference material according to claim 1, characterized in that, Step S4 adjusts the pH to 6.5-7.5 with 1M sodium hydroxide.

7. The method for preparing a certified seawater biochemical oxygen demand reference material according to claim 1, characterized in that, In step S5, the borax and boric acid are both analytical pure, and the addition amounts of borax and boric acid are 1.4-1.7 g / L and 8.4-8.7 g / L, respectively, to maintain the pH of the solution to be stable at 7.

0.

8. A seawater biochemical oxygen demand standard material prepared according to the preparation method of any one of claims 1-7, characterized in that, The seawater biochemical oxygen demand standard material is configured by using aminoglucose hydrochloride instead of glucose and glutamic acid.

9. Use of the seawater biochemical oxygen demand standard material according to claim 8, characterized in that, The seawater biochemical oxygen demand standard material is used for seawater BOD5 determination, standard addition recovery test, and indoor quality control.

Images