GB 17378.5-2007The specification for marine monitoring - Part 5: Sediment analysis (English PDF)

4.1.3 Analysis Preparation step of preparing a sample for analysis of samples

4.1.3.1 Determination of heavy metals (copper, lead, cadmium, zinc, chromium, arsenic and selenium) are as follows:

--- Polyethylene bag wet sample to wash and numbered porcelain evaporating dish, placed in 80 °C ~ 100 °C oven drying process using a glass rod often flip sample and crush the larger pieces, to accelerate the drying;

--- Spreading the dried sample in a clean polyethylene plate, remove gravel and debris particles larger plants and animals. The sample was loaded Ru Manao bowl, each 500mL agate mortar was charged with about 100g dry sample;

--- Agate ball, all through the ground to 160 mesh (96µm) (prior approval of the test to determine the size and number of agate ball milling time and other conditions, is no longer sieved after grinding) in a ball mill. Agate mortar can also be crushed by hand, with a 160 mesh nylon sieve, cover with plastic lid sieved sample to prevent escape. The sample was milled mix well;

--- Quartering and dividing by dispensing 10g ~ 20g prepared sample into the sample bags (filled in station number of samples, levels, etc.), sent to each laboratory for analysis. The remaining sample was poured into a grinding mouth glass jar or sealed plastic jar lid, cap tightly, reserved subsample saved;

--- Operator should wear masks and operate under well-ventilated conditions. Crushed sample and sampling and other tools and utensils were first purification treatment, in order to avoid contamination of the sample.

4.1.3.2 Preparation of sample preparation for determination of analytical sample measured oils, organic carbon, organochlorine pesticides and polychlorinated biphenyls in the following steps.

--- The moisture content had been determined, the sample size and total mercury in the post Spreading been cleaned and numbered enamel plate, placed in the indoor cool air, turning from time to time and the sample crushed chunks, To accelerate the drying, air drying the sample prepared;

--- Spreading the sample which has been dried in a polyethylene plate, remove gravel and debris particles larger plants and animals;

--- In a ball mill to all through 80 mesh (180µm) (in advance by the test conditions, no longer crushed and sieved), can also be manually crushed porcelain mortar, 80 mesh (180µm) sifted metal screen covered with a metal lid. Samples prevent escape. The sample was milled mix well;

--- Quartering and dividing by dispensing 40g ~ 50g prepared sample into the sample bags (filled in station number of samples, levels, etc.), sent to each laboratory for analysis.

4.1.4 Analysis subsample saved To ensure comparability of the test results of the previous voyage monitoring and quality data for the development of marine environmental protection and scientific accumulation of information, Good analysis should be properly preserved subsamples to prepare for QA analysis and other purposes.

4.2 regulations and requirements

4.2.1 Analysis of samples drying. The drying temperature and time are not specified, refer to (105 ± 1) °C, drying 2h.

4.4 Description

4.4.1 various chemical density (rho), is the number of grams per milliliter at 20 °C.

4.4.2 In addition to the items listed ship-site determination of equipment used, the laboratory determination of land within the project, list only the main equipment and special equipment and utensils.

4.4.3 desiccant when not indicate a specific name, refer to color gel.

4.4.4 concentration of the standard elements are formulated refers to the concentration of the element.

4.4.5 does not specify solvent solution is an aqueous solution.

4.4.6 In addition to electrochemical analysis, calibration curve can also be used linear regression equation, mass or concentration of the analyte, then the formula to calculate the content of the analyte in the sample. When a middle point of the calibration curve exception is large, the calculation using the linear regression equation content can cause large errors, It should give up this point, for use as the law required results. As outliers appears across the calibration curve, the range of the calibration curve is correspondingly smaller, it should be redrawn when the calibration curve. The particle size was measured by deposits

4.4.7 GB/T 12763.8 execution.

5.1 Atomic Fluorescence Spectrometry

5.1.1 Scope and Application This method is applicable to the determination of freshwater and seawater stream sediments of total mercury. This method is a method of arbitration.

5.1.2 The principle of the method Samples of nitric acid - hydrochloric acid system, placed in boiling water bath for digestion, the total amount of mercury as ions into solution. With potassium borohydride as reducing agent, the solution ionic mercury into mercury vapor. Argon as a carrier gas of atoms of mercury vapor into the atomic fluorescence spectrometer of atomic reactor to special mercury hollow cathode lamp as the excitation source, the determination of mercury atomic fluorescence intensity.

5.1.3 Reagents and preparation

5.1.3.1 nitric acid (HNO3). rho = 1.42g/mL, pure class distinctions.

5.1.3.2 hydrochloric acid (HCl). rho = 1.19g/mL, pure class distinctions.

5.1.3.3 potassium borohydride (KBH4).

5.1.3.4 potassium hydroxide (KOH). pure class distinctions.

5.1.3.5 oxalic acid (H2C2O4 · 2H2O).

5.1.3.6 Potassium permanganate (KMnO4).

5.1.3.7 potassium hydroxide solution (0.05g/L). Weigh 1g of potassium hydroxide (see 5.1.3.4) was dissolved in 200mL of deionized water, Boron was added 0.5g of potassium hydride (see 5.1.3.3) Pipette 20mL dissolved in 1000mL volumetric flask, dilute to the mark with deionized water. Preparation before use.

5.1.3.8 potassium permanganate solution (1%). Weigh 5g of potassium permanganate (see 5.1.3.6) was dissolved in 500mL of deionized water, placed in a brown reagent bottle to save.

5.1.3.9 oxalic acid solution (1%). Weigh 10g of oxalic acid (see 5.1.3.5) was dissolved in 1000mL of deionized water, placed in a brown reagent bottle to save.

5.1.3.10 nitric acid solution (1 + 19). 1 part of nitric acid (see 5.1.3.1) and 19 parts of water are mixed.

5.1.3.11 mercury standard stock solution (1.00g/L). Weigh accurately 0.1353g mercuric chloride (HgCl2, reference reagents or pure class distinctions, Pre-positioned more than 24h) in sulfuric acid dryer in 50mL beaker, dissolved with a small amount of nitric acid solution (see 5.1.3.10), the total amount transferred to 100mL volumetric flask, In nitric acid solution (see 5.1.3.10) set the volume to the mark, and mix.

5.1.3.12 mercury standard intermediate solution A (10.0mg/L). Pipette 1.00mL mercury stock standard solution (see 5.1.3.11) into 100mL Flask, add nitric acid solution (see 5.1.3.10) set the volume to the mark, and mix.

5.1.3.13 mercury standard intermediate solution B (0.100mg/L). Pipette 1.00mL mercury intermediate standard solution A (see 5.1.3.12) placed 100mL flask, add nitric acid solution (see 5.1.3.10) set the volume to the mark, and mix.

5.1.3.14 mercury standard solution (10.0µg/L). Pipette 10.00mL mercury intermediate standard solution B (see 5.1.3.13) into 100mL Flask, add nitric acid solution (see 5.1.3.10) set the volume to the mark, and mix. Preparation used.

5.1.5 Analysis of step

5.1.5.1 standard curve 5.1.5.1.1 in seven 100mL flask were added 50mL of deionized water was added 10mL of nitric acid (see 5.1.3.1) and 10mL of concentrated hydrochloric acid (see 5.1.3.2), then were added mercury standard solution (see 5.1.3.14) 0mL, 0.25mL, 0.50mL, 1.00mL, 2.00mL, 4.00mL, 8.00mL, water volume to the mark, and mix. 5.1.5.1.2 mercury were taken above the standard series solution of 2mL, measurement standard blank fluorescence intensity readings (I0) and standard sample fluorescence intensity readings (Ii). 5.1.5.1.3 The data recorded in Table A. 3, the fluorescence intensity (Ii-I0) for the vertical axis, the amount of mercury (ng) as the abscissa, the standard curve (Given in linear regression equation) and calculate the linear regression coefficients.

5.1.5.2 sample determination 5.1.5.2.1 accurately weighed 0.1g ~ 0.5g dry sediment samples or 1g ~ 5g wet sediment sample (accurate to 0.0001g), placed 50mL stoppered colorimetric tube, add 2mL nitric acid (see 5.1.3.1), 6mL hydrochloric acid (see 5.1.3.2). With approximately 10mL of deio...