| In recent years,with the development of industry and agriculture in our country and the general population,the organic pollutants in environmental water samples have gradually increased,which has greatly threatened the survival of human beings.Therefore,the analysis,detection and control of organic pollutants in environmental water samples is one of the hot spots in the field of environmental analysis at present.This is of great significance for improving the living environment of human beings and ensuring the health of human beings.However,the components of water quality pollutants are complex,and there are many kinds of pollutants,and there is strong interaction between pollutants and matrix,which makes it difficult to directly detect the target components.In addition,the concentrations of the components to be detected of organic pollutants in water quality samples are usually few(usually in the order of μg/L,ng/L and pg/L),which cannot be directly analyzed and detected,so it is necessary to pre-treat the samples.There are so many pretreatment technologies,but solid phase extraction technology and adsorption are widely used for their advantages of simplicity,rapidity and high efficiency.Based on this,this paper investigates the influence of solid phase extraction fillers and adsorbents on the separation and analysis of organic pollutants in environmental water samples from two directions:solid phase extraction method and adsorption method.The main experimental results are as follows:(1)Using No.9 linear material as solid-phase extraction filler,the solid-phase extraction column used in the experiment was obtained by linear packing.Combining HPLC-MS/MS technology,a new method for simultaneous analysis of methyl tobramycin(TM)and metolachlor(MET)in water samples was established.The best pretreatment con.ditions were determined as follows:No.9 linear material;B column loading;Methanol and ammoniated methanol are used as eluent;The eluent dosage is 2.90 times of the column volume.Isothermal adsorption model showed that Langmuir model could better describe the adsorption of TM and MET pesticides by No.9 material.The linear range of TM and MET in this detection method is 0.2 mg/L～4 mg/L,and the correlation coefficient were 0.9998 and 0.9996,respectively.The limit of detection(S/N≥3)of TM and MET were 0.7 μg/L and 1 μg/L,and the limit of quantitation(S/N≥10)was 5μg/L.The actual sample determination results showed that the average recovery rate was 81.3%～99.3%,RSD was 1.8%～10.0%.It is proved that the method is accurate and can be used for the microanalysis of TM and MET in water samples.(2)The water samples were pretreated by solid phase extraction and determined by MS/MS.The best pretreatment conditions were determined as follows:HCl was used to pretreat No.30 filler,and once pickling,ionization interference of the material itself can be effectively removed.Filler No.30 has adsorption effect on ionizing interferents,sulfapyridine(SP)and sulfamethoxazole(SMZ).Using water as eluent,four times of elution,acetonitrile as eluent and two times of elution,the ionizing interferents can be effectively separated from the target analyte.The No.30 filler treated with HCl can effectively remove the substances that affect mass spectrometry ionization in water samples,which provides the possibility of using high-throughput continuous injection mass spectrometry to analyze more substances in water samples,and it also provides a new way for water quality sample processing.(3)The ZrO2/Al2O3 composite oxide adsorbents were prepared by precipitation method using Al(NO3)3·9H2O and Zr(CH3COO)4 as raw materials.The optimal preparation conditions were determined as follows:Al:Zr molar ratio was 9:1,Ammonium carbonate and ammonia mixed lye were used as precipitants,Calcination reaction temperature of 800℃ time of 4 h.Under the optimal preparation conditions,the specific surface area of the sample was 167.313 m2/g.Using RhB dye as the adsorption model,the adsorption performance of ZrO2/Al2O3 adsorbents was investigated.The results showed that the molar ratio of Al to Zr was 9:1.When ammonium carbonate and ammonia mixed lye were used as precipitant,adsorbent dosage were 40 mg,adsorption time was 12 h,and solution pH=8,ZrO2/Al2O3 adsorbents has the best adsorption effect on RhB dye.The isothermal adsorption model showed that Langmuir model could described the adsorption of RhB dye by ZrO2/Al2O3 adsorbents well,and the maximum adsorption capacity was 40.40 mg/g.After reused 5 times,the adsorption rate of RhB dye solution can reach 89.80%.The regenerability of this adsorbent is 89.96%.The adsorption rates of oxytetracycline and tetracycline on this adsorbent were 100.0%in 1h adsorption reaction time,and the adsorption rates of sulfapyridine and sulfamethoxazole were 0.695%and 24.682%,respectively.It showed that the adsorbent had excellent adsorption properties for oxytetracycline and tetracycline,and it was expected to be used as a solid phase extraction adsorbent for the analysis and detection of tetracycline antibiotics in water. |
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