2019 Vol. 38, No. 1
Due to their heavy use in human health care and industrial food animal production, quinolones occur widely in surface water, soils, and sediments. Development of highly sensitive and selective analytical techniques for the detection of quinolones, often at trace levels, in environmental matrices is necessary to understand their risk to the environment. This review summarizes the recent development in sample pretreatment and determination of quinolone residues in aqueous samples, soils and sediments. Despite the recent development of novel extraction and pre-concentration methods, solid phase extraction (SPE), ultrasound-assisted extraction or microwave-assisted extraction followed by SPE are the most developede and reliable methods for the extraction and enrichment of quinolones in aqueous and solid samples, respectively. Liquid chromatography-fluorescence and liquid chromatography-triple quadrupole tandem mass spectrometry are widely used for the routine analyses of quinolones, while novel immunoassays, biosensors and electrochemical methods show promises as alternatives to the expensive instrumental analyses in screening, particularly for on-site real-time monitoring of these pollutants.
As a typical pharmaceutical, acetaminophen (ACE) has aroused critical concerns owing to its widespread existence and potential toxicity. In this work, ACE degradation by chlorination, UV/H2O2 and UV/chlorine processes was inverestigated. The results showed that ACE could be degraded completely by both UV/Cl and UV/H2O2 processes, and the degradation rate by UV/Cl was higher among the two processes. The degradations processed by UV/H2O2 and UV/chlorine were well fitted by pseudo first order kinetics with the rate constant (kobs,ACE) of 0.1343 min-1 and 0.0657 min-1(293 K, pH=7), respectively. The pH experiments indicated that, compared to other conditions, the degradation efficiencies of chlorination and UV/chlorine at acidic pH were much higher. Differently, the degradation efficiency of UV/H2O2 was slightly changed with pH. The mineralization of ACE was much more difficult than the degradation, and the highest mineralization efficiency was only 5.60% (UV/Cl process) after 60 minutes. Twelve possible transformation products (TPs) were detected in UV/chlorine process, and the transformation path was mainly included hydroxylation, chlorine substitution, dimerization, deacylation and oxidation. Luminescent bacteria experiments were introduced to evaluate the toxicity of the solutions. It was found that the toxicity of the ACE solutions all increased after the three processes, in which chlorination was the most prominent. The different reactive species in each process caused ACE to transform to different TPs, ultimately leading to the different degrad of increases of the solution toxicity.
Sulfonamides (SAs) is a common and widely used class of antibiotics, which have received increasing attention due to their ecological and environmental risks. This study investigated the degradation mechanisms and influencing factors of the reaction of two sulfonamides (sulfonamide sfa, sulfathiazole STZ) with chlorine dioxide (ClO2).The results showed that the reaction of SFA and STZ with chlorine dioxide conformed to the second-order kinetics model, and the reaction rate constants were 505.35 L·(mol·s)-1 and 1382.85 L·(mol·s)-1, respectively, under the condition of pH 5.0 and 25℃. Temperature, pH, humic acid and water quality influenced the reaction rates. The transformation mechanisms of SFA and STZ were dependent on the dosage of ClO2.With excess of ClO2 ([ClO2]:[SAs] ≥ 5), SAs had a certain degree of mineralization, and the transformation products of SFA and STZ were mainly organic acids such as lactic acid, oxalic acid and fumaric acid. While at lower concentrations of ClO2 ([ClO2]:[SAs] ≤ 3), electrophilic substitution reaction occurred, which resulted in the generation of toxic chlorinated products in the solution.
Per-and polyfluoroalkyl substances (PFASs) are a group of anthropogenic organic pollutants that have received great scientific attention due to their environmental persistence, bioaccumulation and potential toxicity. PFASs comprise linear and branched isomers, which show significantly different interfacial transport, bioaccumulation, metabolism and toxicity properties. In order to make accurate environmental and health risk assessment, it is essential to achieve isomer-specific analysis of PFASs. In this paper, the sources, nomenclature and analytical methods of PFAS isomers were introduced, and the new progress on the environmental behaviors and biological effects of PFAS isomers were reviewed. This paper is expected to be helpful in the comprehensive understanding of the transport and fate of PFASs in the environment.
Influence of dissolved organic matter (DOM) in road runoff on the removal and release Cu2+、Pb2+、Cr6+ and Cd2+ in bioretention systems with different media (sand, Fe-Mn bioxide, alum sludge) were investigated. The results showed that DOM-heavy metals synchronous pollution increased the removal efficiency of Cu2+ and Pb2+ by 1%-12% and 2%-7%, and decreased the removal efficiency of Cr6+ and Cd2+ by 3%-10% and 1%-5%, respectively. The release of Cu2+, Pb2+, Cd2+ and Cr6+ was inhibited in the bioretention systems with DOM-heavy metals synchronous pollution in the influent, reducing the concentration of heavy metals in the leaching solution. Compared to the bioretention system with common media, the interception of heavy metals was more easily influenced by DOM-heavy metals synchronous pollution in the bioretention systems with modified media. The heavy metals intercepted in bioretention with modified media were more difficult to release.
The fate and bioavailability of heavy metals are primarily determined by their solid/liquid partitioning and distribution. Mechanism-based geochemical equilibrium models have been developed as an important method in the study of heavy metals speciation. In the present review, starting with the development history of speciation modeling, some geochemical speciation models that had been used widely in the soil environment were described. The quantitative methods of reactive components and geochemically reactive element contents were introduced. And the applications of geochemical speciation model were summarized. Finally the future development and application of the model were prospected.
According to the principle of different sampling density for different land use types, we collected 23851 soil samples from the upstream basin of Guanting Reservoir and Miyun Reservoir, and determined the content of soil arsenic by atomic fluorescence spectrophotometry. Furthermore, we drew the arsenic geochemical isograds using GeoIPAS V3.2 software and evaluated the environmental quality of soil arsenic according to the standard for risk control of soil pollution in agricultural land (trial) (GB15618-2018) and the geoaccumulation index method. The results showed that the relatively high value of soil arsenic content was concentrated in Zhangjiakou basin and valley flat land, and the relatively low value area was mainly distributed on both sides of the river course. Additionally, the minimum content of soil arsenic appeared in the grass land, and the maximum appears in the cultivated land. The average contents of soil arsenic in different land use types were cultivated land(9.61 mg·kg-1), garden land(9.44 mg·kg-1), grass land(9.08 mg·kg-1) and forest land(8.84 mg·kg-1). Secondly, the environmental quality of soil arsenic was good as a whole, and the Chaobai River basin(the upstream basin of Guanting Reservoir) is superior to the Yongding river basin(the upstream basin of Miyun Reservoir). In the survey area, Class I area rate is 99.96%. Specifically, the total number of samples between risk screening value and risk control value were 11, the number of which above risk control value were 2. In the investigation area, Class I area rate is 99.96%. Specifically, the total number of samples between risk screening value and risk control value were 11, and the number of which above risk control value were 2. Thirdly, 77.11% of the survey area maintained the level of arsenic background value, 22.83% of which was mildly to moderately accumulated. It must be pointed out that the proportion of mildly to moderately accumulated area is higher, although there is no intensely accumulated area.
The key issues of phytoremediation in mine tailings are investigation and selection of dominant plants. This work analyzed the contents of heavy metals, and the enrichment and translocation of heavy metals such as Cu, Cd, Zn, Mn,Pb and Ni in the indigenous species in the tailings of Shizishan Tailings in Tongling, Anhui Province,so as to select the pioneer plants for ecosystem restoration of the area.Results showed that among the selected 17 indigenous plants, the mean contents of Cu, Pb, Zn, Cd, Ni and Mn in the plant root soil exceeded the corresponding background values in Shizishan. Robinia pseudoacacia L., Ixeris polycephala C., Taraxacum mongolicum M., Imperata cylindrica L., Crassocephalum crepidioides S., Vicia sepium, Actinstemma Lobatum, Radix Puerariae,Rumex acetosa L., Phytolacca acinosa, Lotus corniculatus L., Brassica napus L., Equisetum ramosissimum D., Hemerocallis citrina B., Gnaphalium affine D. showed a strong translocation ability for more than 2 heavy metals, and could be considered as potential enrichment plants.The enrichment coefficients and translocation factor of Cd in Robinia pseudoacacia L.,Ixeris polycephala C., Crassocephalum crepidioides S., Radix Puerariae, Lotuscorniculatus L. were more than 1. The translocation factor of heavy metal Cu, Pb, Zn and Mn in Imperata cylindrica L., Actinstemma Lobatum are were more than 1, but the enrichment coefficients were less than 1, which indicates Imperata cylindrica L., Actinstemma Lobatum can transfer Cu, Pb, Zn and Mn from the plant root soil to the over-ground part of the plants and to reduce soil heavy metal pollution.
In order to evaluate the pollution characteristics and health risk of heavy metals in topsoil and road dust around the Huangshi-Ezhou of G316 highway, 23 topsoil and 23 road dust samples were collected in the studying area in January 2015. Heavy metal contents were determined by the flame atomic absorption spectrophotometry (FAAS). The results showed that the average concentrations of Cu, Pb, Zn, Cd, Co, Cr, Ni, Mn in topsoil and in road dust were 97.51, 31.18, 115.57, 0.58, 21.20, 30.10, 37.34, 573.74 mg·kg-1 and 730.12, 236.23, 392.74, 6.20, 223.72, 90.54, 148.42, 4698.46 mg·kg-1, respectively. All the observed levels in the dust samples were significantly higher than those in on the topsoil samples. And all the heavy metals (except Cr、Ni、Mn) in road dust of Huangshi section were significantly higher than those in the Ezhou section; The Geo-accumulation index showed that the pollution of Co in the topsoil and Cd, Co, Mn in road dust were the most serious. According to the health risk assessment, the non-carcinogenic risk of 8 heavy metals in topsoil and road dust is children > adults, in which the hand-mouth intake was the main way of heavy metals exposure. The exposure of various heavy metals in topsoil is not significant, but there is non-carcinogenic risk of Cr and Mn in road dust; Cd, Co, Ni, and Cr in the topsoil do not have carcinogenic risk, and the carcinogenic risk of road dust media mainly comes from Cr.
Soil enzyme activities of typical Pinus sylvestris var. mongolica plantations aged 10-60 years in Zhanggutai of Liaoning Province were determined using time-space substitution method. The changes of soil enzyme activities with time (different ages) and location (different depths of soil layers), and the relationships between nutrients and soil enzyme activity were analyzed. The purpose was to study soil degradation of Pinus sylvestris var. mongolica plantations and provide reference for the future study of soil enzyme in the study area. The results showed that the activities of sucrase and protease in the Pinus sylvestris var. mongolica plantations increased with the increase of stand age. The activities of phosphatase and catalase increased at first and then decreased, and reached the highest respectively at the age of 30 years. The soil urease activity increased, and then decreased with the increase of stand age, and remained unchanged at the age of 30 years. The activities of five soil enzymes decreased with the deepening of soil layers, and the surface soil enzyme activity was significantly higher than soil enzyme activity below 20 cm soil layer. With the increase of stand age and soil layer, the change of soil enzyme and physicochemical was similar, indicating that soil physical and chemical properties played an important role in soil enzyme activity. The correlation analysis showed that there was a significant correlation between soil enzyme activities and nutrients, which can be used to characterize soil fertility in forest lands. In summary, the physicochemical properties of forest soil can be improved to reduce the early decline of Pinus sylvestris var. mongolica plantations, and the method of measuring soil enzyme activity can be used to evaluate the comprehensive quality of forest soil in the region.
To explore the possibility of application of cadmium-resistant strains,the optimal preparation conditions were investigated by the single factor and orthogonal experimental design through the immobilized biosorption of cadmium-resistant strain H6(Bacillus cereus) and corn straw biochar by sodium alginate.The effect of recycling of the immobilized beads was determined by the desorption experiments with 1 mol·L-1 aqueous nitric acid as the desorption agent. Bosed on the results, the optimal preparation conditions of the immobilized beads were as follow:The mass fraction of sodium alginate was 4%,the amount of corn straw biochar was 2%,the volume fraction of bacterial inoculation was 25% and the concentration of CaCl2 was 2.5%.The adsorption capacity of the immobilized beads reached to 5.80 mg·g-1,which was higher than SA beads or sodium alginate immobilized biochar or bacteria.The desorption experiments indicated that the immobilized beads have maintained adsorption capacity after four cydes.All the results suggested that the immobilized beads could be recycled effectively with stable adsorption capacity.
Polychlorinated biphenyls (PCBs) are one of the first 12 persistent organic pollutants prohibited by the Stockholm Convention in 2001. As persistent contaminants in the environment, PCBs can be bioaccumulated in organisms and biomagnifed in the food chain due to their lipophilic properties, and are biotransformed into metabolites including hydroxylated PCBs, methyl sulfonated PCBs and PCB sulfates in the liver. These PCB metabolites-generation pollutants may have toxic effects involved with endocrine disruption in aquatic organisms, lead to consequent problems of aquatic products, and this have attracted sustained attention worldwide. In this paper, we reviewed the progress of polychlorinated biphenyls metabolites in the field of quality and safety of aquatic products, mainly including the qualitative and quantitative nalytical methods, toxicity effects, biotransformation mechanism of polychlorinated biphenyls, and summarized the research progress on the types of polychlorinated biphenyl metabolites congeners, residual levels and their effects influence on the quality and safety of aquatic products globally.
Six sampling stations were set up in the eastern region of Laizhou Bay in April and November 2015, and samples of seawater and surface sediments were collected. The contents of 14 polybrominated diphenyl ethers (PBDEs) in the dissolved phase (DP) and suspended particulate matter (SPM) of seawater and in surface sediments were determined by gas chromatography-mass spectrometry. The composition characteristics of PBDEs were analyzed. Principal component analysis (PCA) was used for the identification of the sources of PBDEs, and the ecological risks were evaluated. The results showed that the total contents of 14 PBDEs (∑14PBDEs) in DP, SPM and sediments in April were 0.29-0.76 ng·L-1, 1.79-3.60 ng·L-1 and 31.37-44.39 ng·g-1, respectively, and the contents of BDE209 were 0.21-0.65 ng·L-1, 0.84-2.34 ng·L-1 and 24.27-36.79 ng·g-1, respectively. There was no significant difference between ∑14PBDEs contents in DP and in sediments in April and those in November (P>0.05). However, the ∑14PBDEs contents in SPM in November were significantly lower than those in April (P<0.05). The average proportion of ∑14PBDEs in SPM in April and November was 83.9% and 71.2% in the total contents in DP and SPM, respectively, indicating that PBDEs in seawater were mainly partitioned into the particulate phase. The contents of PBDEs in sediments were positively correlated with the contents of the total organic carbon (r>0.9,P<0.01). Among the 14 PBDE congeners, BDE209 was dominant, followed by BDE47. PCA revealed that PBDEs in the eastern region of Laizhou Bay were mainly derived from the deca-BDEs which were transported by land runoff. The ecological risks from penta-BDEs and octa-BDEs in seawater in the eastern region of Laizhou Bay were low, and those from penta-BDEs in sediments were moderate.
Based on the measured water quality data of 12 rivers in the three major river basins in eight cities in the central, southeastern, northwestern, and eastern parts of Gansu Province from 2011 to 2015, a water environmental health risk assessment model was established.It was found that the health risk caused by Cr(Ⅵ)in all sections was the highest. The sections with the health risk caused by all the pollutants, non-carcinogens and chemical carcinogens during the five-year period were Jing River in Ping Liang, Wei River in Tian Shui and Jing River in Ping Liang. The risk caused by the non-carcinogens in each section was significantly less than the health risk caused by the chemical carcinogens in the section at the same time. The total risk of water environment in 12 sections in 2011-2015 didn't exceed the maximum acceptable risk level set by the USEPA, but neither of them met the negligible risk level.Among them, Jing River in Pingliang had the highest risk, and Wei River in Tian Shui had the lowest risk.
Three hundred and ninety-six water samples were collected in the Dongting Lake from April 2016 to March 2017.Factor characteristics analysis were performed using pH, dissolved oxygen (DO), ammonia nitrogen (NH3-N), total nitrogen (TN), total phosphorus (TP), permanganate index (CODMn), chemical oxygen demand (CODCr) and five-day biochemical oxygen demand (BOD5) as the physicochemical factors. Single-factor assessment method, comprehensive pollution index method and principal component analysis method were applied to evaluate the water quality of Dongting Lake. The water body presented weak alkalinity with TN and TP as excessive pollutants. The single-factor assessment indicated that the first restrictive factors of water quality were TN and TP, while the water quality of Dongting Lake was in Class Ⅴ or lower Ⅴ. The results of comprehensive pollution index assessment showed that the water quality was in a moderate pollution condition, with better water quality in normal period than in other two periods. TN, TP, BOD5 and CODMn were the main pollution factors. The principal component analysis method showed that indexes such as pH, DO, NH3-N and TN, etc, greatly influenced the water quality of Dongting Lake. Water quality of East Dongting Lake was inferior to South Dongting Lake, and South Dongting Lake was inferior to the West Dongting Lake. The three methods were a combination of qualitative and quantitative evaluation. The results of each method were not identical with each other. So it is very important to work on water quality assessment using various methods.
In order to study the photochemical production characteristics of atmospheric ozone in Guiyang City, the concentration of non-methane hydrocarbons in Guiyang was observed at air quality monitoring stations in urban and suburban areas during 2016 when the atmospheric ozone concentration was high. Using the observation-based photochemical model, the typical photochemical processes and sensitivities of atmospheric ozone production near the ground surface were analyzed. By comparing the characteristics of ozone and ozone precursors, simulating the concentrations of the main free radicals and the photochemical chain products in urban and suburban areas, it was found that the characteristics of ozone production in urban and suburban areas of Guiyang were different. By analyzing the relative incremental reactivity of the major precursors of ozone, it was further found that the urban ozone production was mainly controlled by VOCs, and the suburbs were mainly controlled by NOx. The control of anthropogenic alkenes and aromatics is most effective in controlling urban ozone pollution.
In order to explore the spatial-temporal distribution of negative air ions (NAI) and its influencing factors in different ecological function areas of cities. We simultaneously monitored the concentrations of positive and negative ions in air and inhalable particulate(PM10 and PM2.5) and the main environmental factors (air temperature, relative humidity and wind speed) in the typical ecological function areas in Tai'an city, which included square park area, residential area, urban road area and industrial workshop area, and analyzed the dynamic change of NAI in each ecological function area and their correlations with the environmental factors and inhalable particulate. The results showed that the daily variation of NAI concentration in the square park area was obviously single peak form, while those of the residential area, urban road area and industrial workshop area were dual peak forms. The NAI concentration in the square park area was the highest, followed by the residential area, urban road area and industrial workshop area. The order of the average value of CI index in each ecological function area was square park area > residential area > urban road area > industrial workshop area. The trend of daily variation of NAI concentration was similar to that of relative humidity, and it was opposite to that of temperature, positive air ions and wind speed. The order of environmental factor for influencing the daily variation of NAI concentration was relative humidity > air temperature > wind speed. The trend of daily variation of NAI concentration was opposite to that of inhalable particulate (PM10, PM2.5). The inhalable particulate concentration decreased with the increase of NAI concentration. The correlation between the NAI concentration and inhalable particulate concentration was significantly negative, and the degree of the correlation was PM10> PM2.5.
A haze episode occurred in Taiyuan during November 5-6, 2017. The chemical compositions of the particulate matter were studied by single particle aerosol mass spectrometry (SPAMS). The source analysis was carried out according to the fine particle source spectrum library of Taiyuan, and the cause of haze event was also studied in combination with laser radar and meteorological conditions. Results showed that all the particles were classified into 9 main categories:organic carbon (OC), elemental carbon (EC), internally mixed elemental-organic carbon (ECOC), high mass organic carbon (HOC), K-rich, Na-rich, levoglucosan, dust and heavy metals. The appearance of secondary components indicates these particles experienced some degree of aging. The correlation between carbon-containing particles (OC, EC) and secondary particles was higher on clean days than haze days. However, the correlation with of secondary particles were high in both weather conditions. The results of fast source apportionment indicates that vehicle exhaust and coal combustion were main sources during the pollution process. The laser radar and meteorological data analysis showed that the pollution process was caused by the transmission of external pollutants and the adverse weather conditions such as low wind speed, high humidity and low level of the atmospheric boundary layer.
Concentrations of heavy metals and petroleum hydrocarbons in the surface sediments collected from the offshore oil drilling platform in the Penglai 19-3 oil spill accident area of Bohai sea were measured to analyze the variation pattern of the heavy metal concentration with petroleum degradation during the petroleum bioremediation, and the correlation between the two pollutants. The results showed that the concentrations of Cr,Cu,Ni,As and Cd increased first and then decreased with the degradation of oil. In the early stage, the increase of the heavy metal concentration may be related to petroleum degradation. And the later decline may be caused by the function of microorganism and plant, resuspension of sediments or vertical migration of heavy metals. In contrast, the concentration of Pb declined steadily, which may be due to the interaction between effective Pb and root of submerged plants or decreasing of pH and organic matter content in the sediments. Except for As (8.2%), the extent of Cr,Cu,Ni,Pb and Cd reduction ranged from 48.5% to 69.6%. It confirmed that the oil degradation bacteria had a great effect on the remediation of heavy metals.
In situ remediation of arsenic in anoxic groundwater is significant for the sustainable development of humankind. In this study, a wave rectified alternating current electrocoagulation process was developed for the oxidative sequestration of As(Ⅲ) in the simulated anoxic groundwater. The optimal current density, TFe-anode/TMMO-anode ratio and reaction period for As(Ⅲ) sequestration were 4.4 mA·cm-2, 1:2 and 24 s, respectively. Under the optimal conditions, approximately 92% of 500 μg·L-1 As (Ⅲ) was removed after 30 min reaction at pH 8 with the energy consumption of 0.11 kW·h m-3. In addition, the presence of HCO3- and PO43- deteriorated the efficiency of As(tot) sequestration. In this process, the oxidation of As(Ⅲ) to As(Ⅴ) was induced by the intermediate oxidant, i.e., Fe(Ⅳ), produced in the process of O2 reacting with Fe(Ⅱ), followed by the sequestration of As(Ⅴ) by the freshly generated amorphous Fe(Ⅲ) (oxyhydr)oxides.
Woody peat was an used as adsorbent for the removal of Cr(Ⅵ) form aqueous solutions. The effects of solution pH, contract time, dosage of woody peat, buffer concentration and the initial concentration of Cr(Ⅵ) on the removal rate of Cr(Ⅵ) were investigated. The influence of pH on the desorption of Cr(Ⅵ) was examined also. The results show that the removal rate of Cr(Ⅵ) in aqueous solutions decreased with the increase of solution pH and the concentration of phosphate buffer (0.10 to 0.20 mol·L-1). The maximum adsorption amount of 29.98 mg·g-1 was obtained under an initial pH of 4 for 100 mg·L-1 Cr(Ⅵ) treated with 3.33 g·L-1 woody peat. The adsorption kinetics of Cr(Ⅵ) followed the pseudo-first-order kinetic model, and the adsorption isotherm data fitted well with the Langmuir equation. The desorption rate of Cr(Ⅵ) was less than 0.32% when the solution pH was lower than 6.
Perchlorate (perchlorate, ClO4-) is a highly diffusive, difficult to degrade and persistent inorganic pollutant. ClO4- can affect the normal physiological functions of the thyroid, and may cause a certain degree of destruction on red blood cells, liver and kidney. These environmental pollution and human health and safety problems aroused the attention of researchers. Research on the removal and degradation of ClO4- has become one of the most difficult and hottest areas in recent years. At present, main methods of processing and degradation of ClO4- include physical and chemical methods, chemical reduction methods, and biological treatment etc. In this paper, the principles and characteristics of these methods are summarized, and the progress in the mechanisms of adsorption and degradation in recent years is reviewed.
Recovery of sludge protein has become one of the most efficient routes for utilizing waste activated sludge (WAS). It is helpful for the application of WAS protein recovery and will provide useful information for high C/N ratio wastewater containing sulfate from chemical and food industries to study the enhancement of methane production from wastewater of protein recovery. The results showed that the addition of iron and its chelate efficiently enhanced methane production via promoting the activities of key enzymes of hydrolytic acidification and inhibiting those of sulfate reductase. When 10 μmol·L-1 nitrilotriacetic acid (NTA) and 40 mg·L-1 Fe0 were added, the cumulative biogas production rate reached 196.2 mL·g-1 COD. It increased by 123.97%, compared with the control. The polysaccharides were the main substrate for methane production from high C/N ratio wastewater containing sulfate. The hydrolysis of polysaccharides and proteins was the limiting step to improve methane production, compared with the acidification process, by integrating the variations in the activities of key enzymes.
In this paper, a rapid method to determine the petroleum hydrocarbon (C10-C40) in soil was established using new technology, coupled with an efficient 5 m short chromatographic column, and the analysis time was shortened to 3.2 min.The chromatographic fingerprint peak was similar as the conventional method. The particular flow chip and gradient backblow increased the insturmental capacity of resisting disturbance, and decreased column bleeding. The comparison results of two methods indicated that they had the comparable methods parameters. The rapid method has great advantages for huge sample analysis, not only increasing efficiency, but also saving cost.
In order to detect the residues of vancomycin and norvancomycin which are glycopeptide antibioticsins in animal derived foods, a fast analysis method was implemented on a chromatographic system containing online solid-phase extraction (SPE) device that combined with high resolution mass spectrometer (HRMS). Under optimized experimental conditions, the analytes added to blank samples were extracted with appropriate solvent, then purified and enriched on a C18-XL column, whereafter eluted from the purification column onto the analytical columnn (Shiseido CAPCELL PAK ADME column) for chromatographic separation using a gradient elution of 0.1% formic acid water solution and acetonitrile solution. Analytes were detected by Q Orbitrap in positive ion mode with Full Scan/ddMS2. The results showed that the limit of quantitation (LOQ) for each analyte was 0.3 μg·kg-1. In the range of 0.1-50 ng·mL-1, the linearity for each analyte was satisfactory and the value of correlation coecient (r) was more than 0.998. The average recoveries spiked at 0.3, 1.5 and 3 μg·kg-1 were ranged from 80.2% to 93.2%, with the relative standard deviations (RSDs) of 2.8%-9.4%.
Using meat without beta-agonist residues as the blank sample, then enzyme was used to let the animal tissues thoroughly decomposed, and the solid phase extraction was used to cleanse the sample. After extraction and purification, the purified liquid was separated by temperature programmed capillary column after derivatives. The multi-reaction monitoring mode (MRM model) of GC_MS/MS was used for date acquisition, and quantified by internal standard method with deuterium isotope compound as internal standard. Accuracy of the method was based on quality control samples and standard addition recovery rate.The relative standard deviation (RSD) of recovery rate was used to evaluate the accuracy of the method. The correlation coefficient of the 12 beta-agonist residues was in the range of 0.9925-0.9995, and the detection limit was 0.2-0.4 μg·kg-1. The recovery o was 65.5%-110.7% and RSD was 1.16%-8.93%. This method was accurate, reliable and has low false positive rate.