RU2766530C1 - Method for determining the mass content of petroleum products in soils by means of infrared spectrometry - Google Patents

Abstract

FIELD: testing.

SUBSTANCE: invention relates to the field of environmental pollution research and pertains to a method for determining the mass content of petroleum products in soils by means of infrared spectrometry. The method includes extraction of a soil sample, purification of the extract on aluminium oxide, measurement of the optical density of the extract by an IR spectrometer in a cuvette transparent at a frequency of 2,924 cm^-1. In the course of measurements, the soil sample with a weight of 10 g is crushed, extracted with freon 113 twice in the volume of 20 ml, then dried for 10 to 15 hours at a temperature of 20 to 25°C, ground, and extracted again with 20 ml of freon 113. The concentration values measured in all extracts are summed.

EFFECT: provided possibility of determining the content of petroleum products in soils with natural humidity and increase in the reliability of the final result.

1 cl, 1 tbl

Description

The invention relates to the field of studying the level of environmental pollution, namely the determination of the content of oil products (NP) in soils contaminated with light NP, using IR spectrometry methods.

A known method for determining the content of petroleum products in the soil according to GOST Ρ 54039-2010 [1].

The main disadvantages of this method:

- sample preparation according to this GOST (drying, grinding in a mortar, sifting) leads to a significant loss of NPs that pollute the soil;

- the process of calibration of the IR spectrometer is also very complicated;

- to determine OP in soils, GOST P 54039-2010 recommends using as a base method the method for determining oil products by extracting OP from soils with carbon tetrachloride, which, according to our experience, does not extract even half of the kerosene contained in the soil sample.

The main objective of the described invention and the required technical result achieved using the invention is the creation of a method for express IR spectrometric determination of the total content of petroleum products, including light ones, in soil of any type.

When implementing a method for determining the mass content of oil products in soils by infrared spectrometry, including the extraction of a dried soil sample, purification of the extract on aluminum oxide, measurement of the optical density of the extract with an IR spectrometer in a cuvette transparent at a frequency of 2924 cm-1, a soil sample weighing 10 g is crushed, extracted with freon 113 twice, 20 ml each, then dried for 10-15 hours at a temperature of 20-25°C, ground in a mortar and again extracted with 20 ml of freon 113, and the values of NP concentrations measured in all extracts are summarized.

The research was carried out on the territory of a man-made kerosene deposit. To obtain sufficient statistical material, more than a hundred wells were drilled and 230 soil samples were taken. Samples were taken to a depth of 4.5 m.

The most complete extraction of kerosene from soils was achieved in the following way:

A soil sample (usually weighing 10 g) was crushed (not ground) in a mortar, and then extracted with two portions of freon-113, 20 ml each. The soil sample remaining after extraction was dried at a temperature of about 23-25°C, ground in a mortar (not sieved) and again extracted with two portions of freon. The eluate after extractions was purified on a chromatographic column with alumina and filtered with a paper filter. Thus, each sample was analyzed twice - once in the wet state, and the second time after drying. The kerosene content was measured using an IKAN-1 IR spectrometer. The concentration values obtained from the measurement of wet and dry samples were then added.

At the same time, the content of NPs was determined in accordance with RD 52.18.575-96 [2], but the extraction was carried out with freon X-113, because in the process of research, it turned out that when extracting samples with carbon tetrachloride, significant errors occur in determining the content of kerosene. It should be noted that industrial freon must be purified by distillation.

Solutions of kerosene TC-1 in purified freon X-113 were used to build calibrations.

Table 1 presents the results of determining the content of kerosene for various types of soils, which were selected during the survey of the territory of the technogenic deposit.

The results presented in Table 1 show that the developed method is suitable for determining the content of light NPs in almost any soil. The determinations carried out by us according to RD 52.18.575-96 are presented in the table in the column "Standard method".

In our experience, it seems necessary to use the described method instead of the existing one according to GOST Ρ 54039-2010, since it allows determining the content of oil products in soils with natural moisture, which significantly increases the reliability of the final result.

LIST OF USED SOURCES

1. GOST Ρ 54039-2010 "Soil quality. Express method of IR spectroscopy for determining the amount and identification of soil pollution by oil products" // M.: 2001. 5 p.

2. RD 52.18.575-96 "Methodological guidelines. Determination of the gross content of oil products in soil samples by infrared spectrometry. Methods for performing measurements" // M .: Introduction date 04/01/1999. 11 p.

Claims (1)

A method for determining the mass content of oil products in soils by infrared spectrometry, including extraction of a soil sample, purification of the extract on aluminum oxide, measurement of the optical density of the extract with an IR spectrometer in a cuvette transparent at a frequency of 2924 cm ^-1 , characterized in that a soil sample weighing 10 g is ground , extracted with freon 113 twice in 20 ml, then dried for 10-15 hours at a temperature of 20-25°C, triturated and again extracted with 20 ml of freon 113, and the concentration values measured in all extracts are summarized.