1 Introduction

Environmental water quality monitoring is an important component of environmental monitoring and a fundamental task of environmental protection. Its purpose and significance are to grasp and evaluate the water environment quality status and development trend of a region through environmental water quality monitoring. Strengthening the quality control of environmental water quality monitoring and improving the quality of environmental water quality monitoring are of great significance for the formulation and implementation of water pollution prevention and control plans. 2 Factors affecting the quality of environmental water quality monitoring 2.1 Standardization of sampling process

The standardization of the sample collection process directly affects the representativeness and completeness of the samples, and is a prerequisite for ensuring the accuracy, precision, and comparability of monitoring results. The layout of sampling sections and sampling points, the determination of sampling frequency and sampling methods, the selection and washing of sampling containers, as well as the pre-treatment, storage, and transportation of samples, all have an impact on the representativeness and integrity of the samples. 2.2 Laboratory Environmental Conditions

Factors such as laboratory temperature, humidity, cleanliness, lighting, vibration, noise, and radiation can affect the monitoring results by affecting the temperature of analytical instruments.

2.3 Analytical instruments and reagents

The measurement range and sensitivity of analytical instruments have a direct impact on monitoring results. If the sensitivity of the instrument is low, it will reduce the accuracy of measuring low concentration samples, and the lower the sample concentration, the greater the error. Insufficient purity of the drugs used in the monitoring process can lead to concentration errors in the prepared reagents, reducing the accuracy of the monitoring results. The same effect can also occur if the purity of the water used to prepare the reagents is not sufficient. 2.4 Selection of Monitoring Methods

The methods used for monitoring should be selected based on the type of substance to be tested and the type of instrument used. Different monitoring methods may have varying degrees of accuracy and precision, as well as different detection limits, which can affect the monitoring results. 2.5 Testing Process

During the testing process, the proficiency and standardization of the operators have a significant impact on the test results. Operators with higher proficiency make fewer operational errors, which can ensure the improvement of the quality of monitoring results; The handling and calculation of outliers can also have an impact on the measurement results. 2.6 Data Analysis and Processing

Data processing directly determines the accuracy of monitoring results and should be strictly carried out in accordance with standards; When choosing between available data, certain principles must be followed, such as Dixon test, Grubbs test, etc., to ensure the authenticity of the measurement results

Reality.

3 Key points of water quality monitoring and quality control technology 3.1 Quality control during laboratory preparation stage

Before analyzing and measuring the sample, it is necessary to ensure the safety and cleanliness of the laboratory environment and avoid contaminating the sample. The laboratory should have a fume hood, and when it comes to the use of volatile drugs, experiments should be conducted inside the fume hood. For large precision instruments, it is necessary to ensure that the location is ventilated and clean, and that the temperature and humidity of the environment will not have adverse effects on the instrument.

The drugs and reagents in the laboratory should be stored reasonably to ensure that their properties do not change and to avoid contamination during use, which may affect the purity of the drugs. Containers such as beakers and test tubes should be cleaned thoroughly to ensure that they do not contain impurities inside, in order to avoid interference with the measurement results. 3.2 Quality Control of Monitoring and Analysis Process (1) Setting Parallel Samples in Measurement

Random errors are inevitable in the process of sample measurement. To reduce the impact of random errors, parallel samples can be added to the measurement. By testing two or more groups of samples under the same conditions, the interference of random errors on the measurement results can be significantly reduced. Normally, analysis requires a certain proportion of parallel double sample measurements on the sample, and under the premise of error free operation, the sample can basically meet the requirements. (2) Determination of blank samples

Setting a blank sample in the measurement is to prevent the reagents added during the experiment from affecting it

An effective method for determining the impact of measurement results. However, blank samples of reagents cannot eliminate the interference of substances that may exist in the sample, so sometimes blank samples of the sample need to be prepared. In order to reflect the impact of the sampling process on the test results, a full program blank analysis can also be conducted, which means that the sampling personnel collect, store, and transport pure water as a sample from the laboratory before sampling, and then send it to the laboratory for testing together with conventional samples after sampling is completed.

3.3 Quality Control in Data Processing

Data processing is the final stage of water quality monitoring and a key step in drawing experimental conclusions, which can directly affect the quality of monitoring results. Its main tasks include organizing monitoring records, analyzing the validity of monitoring data, conducting statistical tests on monitoring data, and conducting regression analysis on monitoring data. Therefore, the selection of data is crucial. If data with large errors is selected, it will reduce the specificity of monitoring results. However, if data is blindly selected without basis, it will make the results lose representativeness. 4 Water quality monitoring and quality control measures 4.1 Personnel training

With the continuous development and progress of science and technology, the technical means of water quality monitoring work are also constantly improving, and the learning and training of testing personnel need to be constantly updated. Train employees through various channels and means to promote their learning and continuously improve their professional and technical skills.

4.2 Regular calibration and maintenance of instruments and equipment

Testing work cannot be separated from instruments and equipment, and the correct and reasonable use of instruments and equipment

The quality of monitoring results plays a crucial role. In order to ensure the accuracy, reliability, and comparability of detection data, regular mandatory calibration of instruments and equipment is carried out according to their calibration and calibration cycles. 4.3 Sampling Quality Control

Usually, water quality monitoring data should meet the "five characteristics": representativeness, accuracy, precision, comparability, and completeness. Representativeness means that the collected samples must be effective and reflect the true condition of water quality. Failure to collect samples is considered an invalid sample, and subsequent testing work is meaningless.