Diazepam (DZP), a benzodiazepine sedative, has been increasingly detected in various aquatic products including fish, shrimp, and crab in recent surveillance studies, raising public health concerns. This study systematically investigates the residue behavior, metabolite profile, and dietary risk of DZP in grass carp (Ctenopharyngodon idella) following oral administration at a dose of 500 μg/kg body weight. Concentrations of DZP and its metabolites in plasma and tissues were determined using ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), and the drug concentration-time data were fitted using a non-compartmental model embedded in WinNonLin 6.1 pharmacokinetic software. The results indicate that DZP exhibits prolonged elimination kinetics, with tissue elimination half-lives (T1/2λz) ranging from 309.44 to 509.75 h, and residues in skin-on muscle did not fall below the limit of quantification until 98 days. Metabolite analysis identified nordiazepam as the primary metabolite, with its concentration surpassing that of the parent compound by Day 21 post-administration, establishing it as a reliable residue marker for DZP in grass carp. The peak human health risk index (HRI) value was 0.392 on Day 4, remaining above the alert threshold (HRI ≥ 0.1) for 21 days, though all values remained below the safety limit (HRI < 1). These findings provide critical data to support the regulation of aquaculture practices and the assessment of dietary exposure risks associated with DZP-contaminated aquatic products.

Enrofloxacin is a broad-spectrum fluoroquinolone antibiotic widely used in aquaculture. It is primarily employed for the prevention and treatment of infectious diseases caused by common pathogenic bacteria such as Aeromonas, Edwardsiella, and Vibrio. This study investigated the pharmacokinetics, withdrawal period, and dietary risk of enrofloxacin in largemouth bass (Micropterus salmoides) following bath administration. Preliminary trials (5-40 mg/L) revealed dose-and time-dependent drug absorption, leading to the selection of a 40 mg/L for 6 h regimen for the main experiment. Enrofloxacin and its metabolite ciprofloxacin were quantified using a validated HPLC-FLD method, and pharmacokinetic parameters were analyzed by non-compartmental modeling. The results showed that enrofloxacin was rapidly but unevenly distributed among tissues. Peak concentrations were reached immediately in plasma, muscle with skin, and kidney, whereas peak levels in the liver were delayed by 1 h. Total tissue exposure, expressed as the area under the concentration-time curve from zero to infinity (AUC(0-infinity)), exhibited a descending order: plasma > kidney > liver > skin-on muscle. Although elimination was generally slow, tissue-specific differences were observed: the half-lives were comparable in plasma, skin-on muscle, and kidney (approximately 134-140 h), but significantly shorter in the liver (90.56 h). PK/PD analysis indicated potent efficacy against susceptible pathogens (MIC <= 1.1 mu g/mL) and a low risk of resistance development. In contrast, dietary risk assessment suggested a potential health concern (HQ >= 1) within 72 h post-treatment. Accordingly, a withdrawal period of 37 days (925 degrees C & sdot;days) was established for muscle with skin to ensure that total residues (enrofloxacin + ciprofloxacin) fell below the maximum residue limit (MRL). This study provides a scientific basis for the rational use, withdrawal time determination, and food safety evaluation of enrofloxacin in largemouth bass under bath administration.

Diazepam (DZP), a benzodiazepine medication, is extensively utilized in both human and veterinary medicine and has been frequently detected in fish populations. The use of DZP-laced bait is identified as a predominant contributor to drug residue contamination in fish. Nonetheless, our understanding of the residue profile of DZP in fish and its potential implications for human health remains constrained. This study investigated the residue behavior and dietary intake risks of DZP and its primary metabolites in crucian carp (Carassius auratus) following oral administration. A rapid and sensitive UHPLC-MS/MS method was developed and validated for the reliable quantification of DZP and its identified metabolites. The findings revealed rapid absorption and extensive distribution of DZP in crucian carp, with peak concentrations in plasma and tissues occurring at 1 h. The distribution pattern of DZP, based on calculated AUC, was kidney > liver > plasma > gill > muscle plus skin. The distribution of DZP in plasma and tested tissues followed the decreasing order of kidney > liver > plasma > gill > muscle plus skin according to the calculated AUC. DZP elimination was notably slow, particularly in muscle plus skin, with an elimination half-life of 619.31 h, necessitating at least 70 days for concentrations to fall below the limit of quantitation, suggesting a high likelihood of residue formation in fish from oral DZP administration. DZP was metabolized into nordiazepam and temazepam in crucian carp; nordiazepam is the main metabolite of DZP, which is gradually higher than the parent drug in the elimination phase. The dietary risk assessment suggested that a possible health risk (HQ ≥ 0.1) was found within 1 day via ingestion of crucian carp after an oral dose of DZP, suggesting that frequent consumption of high-residue crucian carp may cause harm to human health.

Fipronil residues pose public health concerns and have raised global attention. To ensure the quality and safety of aquatic products, this study developed a modified QuEChERS method coupled with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for synchronous detection of fipronil and its metabolites in various types of aquatic products, including fish, echinoderms, crustaceans, and molluscs. Based on the chemical properties of the target compounds and the complex matrix of aquatic products, this study focused on optimising parameters such as extraction conditions and the composition and ratio of adsorbents to achieve the best adsorption effect. The samples were extracted with acidified acetonitrile and purified using a mixture of neutral aluminium oxide, N-propylphthalimide, and graphitised carbon black before instrumental analysis. Qualification was performed using the internal standard method. Excellent sensitivity (with a limit of detection ranged from 0.1 to 0.3 mu g/kg), satisfactory linearity (r2 >= 0.997), good recovery (85.8% - 110.4%) and good precision (intra-day relative standard deviation < 14.1% and inter-day relative standard deviation < 13.0%) were obtained. The method validation results confirmed that this proposed method was convenient, efficient, cost-effective and reliable for the determination of fipronil and its metabolite in actual aquatic samples. Additionally, it has excellent application potential for quantitative analyses and risk assessment of fipronil residues in marine fish samples collected from South China, providing a new detection strategy and technical support for the routine screening of pesticides in aquatic products.

A QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method was developed to provide good analytical results for teicoplanin (TEC) and ramoplanin (RAM) residues in aquatic products. The analytes was extraction from aquatic product samples using chitosan in the QuEChERS procedure. Compared to conventional adsorbents, chitosan has a relatively good purification ability for the targets. The matrix effects of aquatic products, such as crucian carp, carp, silver carp, tilapia, mandarin fish, turbot, shrimp, sea cucumber and so on, were evaluated by high performance liquid chromatography coupled to triple-quadrupole tandem mass spectrometry. Throughout the validation experiments, the limits of detections and quantifications ranged from 0.4 similar to 0.8 mu g kg(-1) and 1.0 similar to 3.0 mu g kg(-1), respectively. Calibration curves showed correlation coefficient values higher than 0.998 in range between 1 and 100 mu g kg(-1). The recoveries ranged from 89.8 % to 110.0 % with relative standard deviation less than 7.2 % in nine typical aquatic products. The method shows low matrix effect (-18.5 %similar to-2.6 %) for all targets in different aquatic products. The proposed methods proved to be reliable, effective and enables rapid determination of large batch samples, indicating its good applicability for detection and monitoring of TEC and RAM residues in aquatic products.

The toxicity of the two enantiomers of metalaxyl is significantly different and, for food safety concerns, stereoselective analysis of its residues is extremely important in animal muscle tissues. Herein, a simple, sensitive and reproducible method for the simultaneous stereoselective analysis of metalaxyl and its metabolite metalaxyl acid in animal-derived foods has been established based on mixed-mode anion exchange solid phase extraction and chiral liquid chromatography-tandem mass spectrometry. Under the optimized separation and sample pretreatment conditions, good linearity (r > 0.99) was obtained for four target analytes in four animal muscle tissues including bovine, chicken, swine and fish. Mean recoveries of all enantiomers in muscle tissue samples were 89.5-110.3 % with relative standard deviations below 12.4 %. The limits of quantification of the analytes were 0.3-1.0 mu g/kg. The proposed method provides an effective means to monitor the enantiomer residues in real samples whether using highly active R-metalaxyl or racemic mixture drugs.

A simple and sensitive method for the determination of amphenicol antibiotic (chloramphenicol, thiamphenicol and florfenicol) residues in aquaculture products was developed based on a response surface methodologymodified QuEChERS (quick, easy, cheap, effective, rugged and safe) method combined with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The pretreatment method was optimized via single-factor experiments and response surface methodology based on central-composite design to maximize the extraction efficiency and purification effect. The results show that chloramphenicol, thiamphenicol and florfenicol had good linearity in the range of 0.1-50 ng/mL. The recoveries of these amphenicol antibiotics in 12 types of aquaculture products ranged from 78.6% to 106.2% with relative standard deviations less than 12.1%. The method had high sensitivity with the limit of quantification of analytes being 0.01-0.04 mu g/kg. Finally, the developed method was used to analyze actual samples. The results show that this method has good application potential for detecting residues of amphenicol antibiotics in aquaculture products.

Metalaxyl is widely used as a racemic mixture to control various plant and aquatic animal diseases caused by fungal infection. It has been proved that the two enantiomers of metalaxyl have significant differences in activity and toxicity, while little is known about the pharmacokinetics and residual elimination of the individual enantiomers of metalaxyl in aquatic animals. In this study, a simple, sensitive and reliable chiral liquid chromatography-tandem mass spectrometry method was established for the determination of metalaxyl and its metabolite metalaxyl acid enantiomers, which was applied to study the stereoselective pharmacokinetics and residue elimination of individual enantiomers in snakehead (Channa argus). The snakehead was bath administered with the racemic metalaxyl and the highly active enantiomeric R-metalaxyl, respectively. The results showed that the elimination of metalaxyl in the plasma and tissues of snakehead was enantioselective. The concentration of metalaxyl in tissues was kidney > liver > muscle, and preferential degradation of the R-metalaxyl enantiomer was observed in three tissues. However, no transformation between metalaxyl enantiomers was observed in snakehead plasma and tissues when R-metalaxyl enantiomer was administered. In addition, the distribution of metalaxyl acid enantiomers in tissues is closely related to the parent compound metalaxyl, and S-metalaxyl acid was only observed in the kidney and slowly eliminated. The highest concentrations of both metalaxyl and metalaxyl acid were observed in the kidney, suggesting that kidney is the major site of metalaxyl metabolism in snakehead. Given that the highly active R-metalaxyl has a shorter half-life and does not undergo transformation between enantiomers in snakehead, it may be a better choice to use R-metalaxyl instead of racemic metalaxyl in clinical practice. The results are helpful to understand the detailed fate of metalaxyl enantiomers and should be considered in future aquaculture, environmental pollution risk and food safety evaluations.

A Quick, Easy, Cheap, Effective, Rugged and Safe pre-treatment method (QuEChERS) was established to evaluate the risk of tetracycline residues in the muscle of Channa argus. The Box-Behnken design (BBD) response surface optimization method was used to optimize the extraction and purification conditions. The samples were extracted with 10 mL acetonitrile (containing 1% formic acid) and 2 mL 0.1 mol/L Na2EDTA-Mcllvaine buffer solution, and the extracts were purified by 150 mg primary secondary amine（PSA）and 200 mg C18, and detected with Ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The result showed that the calibration curve was linear in the range of 0.50~100 ng/mL, with high correlation coefficients (r≥0.999). The limits of detection (LOD) and quantification (LOQ) were 0.25～0.75 μg/kg and 0.84～2.00 μg/kg, respectively. The average recoveries of tetracycline, oxytetracycline, chlortetracycline and doxycycline at three different spiked levels in the muscle of Channa argus were 89.5%～118%, with relative standard deviations (RSDs) of 1.11%～8.88%. This method is simple, sensitive and accurate, and can be used for the rapid quantitative determination of tetracyclines in Channa argus.

•A sensitive and rapid method for the simultaneous determination of three amphenicol antibiotic (chloramphenicol, thiamphenicol and florfenicol) residues in aquaculture products was developed using UPLC-MS/MS.•A modified QuEChERS method was optimized using single-factor experiments and response surface methodology.•Mean recoveries of chloramphenicol, thiamphenicol and florfenicol in 12 types of aquaculture products ranged from 78.6% to 106.2% with RSDs less than 12.1%.•The limit of quantification of chloramphenicol, thiamphenicol and florfenicol were 0.01–0.04 μg/kg.

Enrofloxacin (ENR) is widely used in aquaculture practice, but little is known about its pharmacokinetic, withdrawal period and dietary risk in fish via bath administration. The purpose of this study was to provide data support for the use of ENR bath therapy in the northern snakehead (Channa argus). The pilot study was carried out to evaluate the therapy concentrations of ENR in northern snakehead with immersion concentrations ranged from 5 to 40 mg/L for 6 h. Based on results of the pilot study, an ENR immersion concentration of 20 mg/L was used for the formal experiment. At this dose, the peak concentrations of ENR in plasma, muscle plus skin, liver and kidney were 4.85, 4.55, 3.87 and 7.42 μg/mL (or g), respectively. According to the AUC0-∞ values, the distribution of ENR in northern snakehead followed the order of kidney > plasma > liver > muscle + skin. The elimination of ENR in northern snakehead was very slow, the half-lives (T1/2λz ) were up to 90.31, 85.5, 104.56 and 120.9 h in plasma, muscle plus skin, liver and kidney, respectively. Ciprofloxacin (CIP) was not detected in any samples in the pilot study and was only occasionally detected in muscle plus skin and liver samples in formal experiment. Based on the calculated PK/PD index AUC/MIC and Cmax /MIC, the current bath treatment regimen will have a good therapeutic effect on infections caused by bacteria with MIC below 0.6 μg/mL. The dietary risk assessment suggested that there was a dietary risk (Hazard Quotients > 10%) until day 6 after bath treatment. It is mandatory for ENR to maintain a withdrawal period of at least 450°C-day in northern snakehead after bath treatment ceased.

In this study, a multi-residue determination method of QuECHERS combined with UHPLC-MS/MS was developed to determine nine β-lactam antibiotics (penicillin G, amoxicillin, ampicillin, cephalexin, cefquinome, ceftiofur, cefazolin, cephapirin, cefuroxime) in aquaculture products. All the nine β-lactam antibiotics exhibited excellent linearity within the range of 2.0–200 ng/mL (cefuroxime: 5.0–200 ng/mL, r greater than 0.999), while the limits of detection (LODs) and quantification (LOQs) were 2.0–5.0 μg/kg and 5.0–10.0 μg/kg, respectively. The recoveries of this method in five aquaculture products (Penaeus Orientalis, Cyprinus Carpio, Channa Argus, Aristichthys Nobilis, and Ctenopharyngodon Idella) ranged from 85.4% to 113.3% and the intra-day and inter-day precisions (%RSDs) were less than 15%. The results suggested the feasibility of this method as a rapid, simple, and accurate approach for determining the residues of the β-lactam antibiotics in aquaculture products.

本研究以QuEChERS作为样品前处理手段,建立了测定水产品饲料中地西泮残留的气相色谱-质谱法(GC-MS).样品经纯水和乙腈提取后加入无水硫酸钠除水及氯化钠盐析,提取液经吸附剂中性氧化铝、PSA、纳米二氧化锆结合GCB粉净化后上机检测,内标法定量.结果显示:地西泮在5～500μg/L质量浓度范围内线性关系良好,相关系数为0.9992,对配合饲料、浓缩饲料及饲料添加剂开展3个水平加标回收实验(0.15、0.25、0.50 mg/kg),方法加标回收率为86.3％ ～104.5％,相对标准偏差为1.4％ ～7.8％,地西泮的检出限为0.05 mg/kg,定量限为0.20 mg/kg,方法检出限远低于标准"NY/T 934—2005"的方法检出限1.00 mg/kg.该法具有前处理过程简单、快速、灵敏度高的优点,适合各种水产饲料中地西泮残留的测定.

The pharmacokinetics, tissue distribution, and elimination of enrofloxacin (ENR) and its metabolite ciprofloxacin (CIP) were investigated to the crucian carp (Carassius auratus gibelio) after single (20 mg/kg b. w.) and multiple oral administration (20 mg/kg b.w. one time daily for 5 days) at 28°C. The concentrations of ENR and CIP in the plasma and tested tissues (muscle/skin, liver, and kidney) were detected simultaneously by high-performance liquid chromatography (HPLC), and the pharmacokinetic data were analyzed with a non-compartmental model using WinNonLin 6.1 PK software (Pharsight Corporation, Mountain View, CA, USA). The pharmacokinetic characteristics of ENR in crucian carp exhibited slow absorption, wide tissue distribution, and long elimination half-life. In the single-dose group, the peak concentrations (Cmax) of ENR in the plasma, muscle/skin, liver, and kidney were 8.93 μg/mL, 13.9 μg/g, 31.2 μg/g, and 27.3 μg/g, respectively, observed at 3 h, 6 h, 1 h, and 3 h after dosing. The elimination half-lives (T1/2λz) of ENR in plasma, muscle/skin, liver, and kidney were calculated to be 67.4, 82.8, 94.4, and 114 h, respectively. In the multiple-dose group, the Cmax of ENR in the plasma, muscle/skin, liver, and kidney were 18.4 μg/mL, 26.8 μg/g, 82.8 μg/g, and 74.5 μg/g, respectively, achieved at 3 h, 6 h, 1 h, and 1 h after the last dose. The T1/2λz of ENR in the plasma, muscle/skin, liver, and kidney were calculated to be 76.4 h, 91.5 h, 114 h, and 148 h, respectively. During the multiple-dose administration, significant accumulations of ENR and CIP were observed in the plasma and tissues of crucian carp, possibly due to their long elimination half-lives. In both dose groups, the AUC0−∞ for both ENR and CIP followed the order of liver > kidney > muscle/skin > plasma. The finding suggested that the liver may play an important role in the metabolism of ENR. According to the calculated PK/PD indices of Cmax/minimum inhibitory concentrations (MIC) and AUC24h/MIC, the multiple-dose regimen would be highly effective against pathogenic bacteria with a MIC value of ≤ 1.84 μg/ml. Depletion studies indicated that a withdrawal period of at least 29 or 32 days was necessary to guarantee food security after single or multiple oral gavage administration at 28°C.

采用QuEChERS前处理技术,建立了鱼肉中6种替考拉宁组分的高效液相色谱-串联质谱检测方法.搅碎均匀的鱼肉样品经乙腈-10％三氯乙酸(6:4,体积比)提取,100 mg乙二胺-N-丙基硅烷(PSA)净化后,使用Agilent SB C18(2.1 mm×100 mm,1.8μm)色谱柱分离,以0.1％甲酸乙腈和0.1％甲酸为流动相进行梯度洗脱,采用电喷雾电离正离子(ESI+),多反应监测模式(MRM)进行检测,内标法定量.考察了提取溶剂种类与体积、吸附剂种类与用量对目标化合物回收率的影响.评价了6种目标物在不同鱼肉基质中的基质效应.在优化条件下,6种替考拉宁组分在4 min内得到良好分离.目标物在各自浓度范围内线性良好,相关系数(r2)均不小于0.998;在5.0、10.0、25.0μg/kg 3个加标水平下,各组分的回收率为84.3％～93.3％,日内相对标准偏差和日间相对标准偏差(n=6)分别不大于7.0％和6.2％,方法的检出限和定量下限分别为0.5～2.0μg/kg和2.0～5.0μg/kg.采用该方法对采集的9种40个鱼肉样品进行检测,所有样品均未检出替考拉宁组分.该方法简单、灵敏、准确、可靠,可用于鱼肉中6种替考拉宁组分的定量分析.

利用固相萃取(SPE)/超高效液相色谱-串联质谱(UPLC-MS/MS)建立了稻渔水体中氟虫腈及其代谢物(氟甲腈、氟虫腈砜和氟虫腈亚砜)的分析方法.根据目标物的化学性质及稻渔水样的基质情况,筛选出适用于稻渔水样预处理的滤膜及稻渔水体中目标物的萃取方法,并对固相萃取条件、氮吹温度等参数进行优化.稻渔水样经玻璃纤维滤纸过滤后,由Supelco ENVI-18固相萃取柱富集、净化,采用SB-C18柱(2.1 mm×100 mm,1.8μm)进行分离,在电喷雾电离源负离子模式下进行检测,外标法定量.结果显示:目标物在0.5～100 ng/mL范围内线性关系良好,相关系数(r2)大于0.998,检出限为0.5 ng/L,定量下限为1.5 ng/L;在2、5、50 ng/L加标水平下的回收率为81.6％～105％,相对标准偏差为3.5％～7.0％.该方法操作简便、灵敏、高效、性价比高,可用于稻渔水体中氟虫腈及其代谢物的同时测定.

Pyrethroids pesticides (PPs) are the widely adopted synthetic pesticides for agriculture and fishery. The frequent use of these pesticides leads to the accumulation of residues in the freshwater environments in China, subsequently affecting aquatic organisms and ecosystems. However, there are few reports on the toxicological and risk assessment of aquaculture aquatic products. In this study, the uptake, depuration kinetics and potential risk to human health and ecology of fenpropathrin, cypermethrin, fenvalerate, and deltamethrin were assessed using tilapia. The results indicated that four PPs were readily accumulated by tilapia. The bioconcentration factors (BCF) of the PPs in plasma and muscle were between 71.3 and 2112.1 L/kg and 23.9–295.3 L/kg, respectively. The half-lives (t1/2) of muscle and plasma were 2.90–9.20 d and 2.57–8.15 d. The risks of PPs residues in the muscle of tilapia and exposed water were evaluated by hazard quotient (HQ) and risk quotient (RQ). Although PPs residues in tilapia had a low dietary risk to human health, the residues in the exposed water had a high ecological risk to fish, daphnia, and green algae. Therefore, assessing the PPs content in freshwater aquaculture and monitoring their dosages and frequencies are highly necessitated to avoid their adverse effect on the aquaculture environment.

It is great challenge to design a simple approach to prepare Co-based N-doped carbon catalysts with high activity and minimum impact to the environment. Here, a novel carbonized poly(dopamine)-coated cobalt nanocomposite (CPDA@Co0) was synthesized via a simple and "zero-organic solvents" approach and employed to activate persulfate (PS) for sulfamethoxazole (SMX) degradation. The CPDA@Co0/PS system exhibited outstanding performance on SMX degradation over a wide pH range (3.0-8.5), and facilitated by acidic conditions and Cl-. For fair comparison, CPDA@Co0 under slightly acidic pH exhibited a much higher rate constant (0.121 min-1) than many reported catalysts. A direct electron-transfer pathway played a leading role in the oxidation, while adsorption of SMX on the surface of CPDA@Co0 might be the determining step. Since the synergistic effect between adsorption and catalysis, 10 mg/L SMX could be completely removed within 25 min, which provided a new strategy for removing organic pollutants from wastewater. Besides, the special core-shell structure could efficiently protect inner Co0 core from leaching. CPDA@Co0 could be easily separated via a permanent magnet and reused at least 5 times. This study might inspire others to develop effective and green PS activation processes for application in SMX treatment.

以QuEChERS作为样品前处理手段,建立测定水产品中扑草净残留的气相色谱-质谱法(GC-MS).样品以乙腈-二氯甲烷(V∶V=8∶ 2)混合溶液提取,提取液经吸附剂中性氧化铝、N-丙基乙二胺(PSA)、纳米二氧化锆结合石墨化炭黑(GCB)净化后上机检测,内标法定量.结果显示,扑草净质量浓度介于5～200 μg·L-1线性关系良好,相关系数(R2)为0.999 9.对草鱼(Ctenopharyngodon idellus)、鳜(Siniperca chuatsi)、中国对虾(Penaeus chinensis)、海参(Holothuria sp.)和文蛤(Meretrix meretrix)进行4个水平的加标回收实验(10、20、40和200 μg·kg-1),方法的加标回收率为85.8％～111.8％,相对标准偏差为1.2％～8.8％,满足GB/T 27404-2008《实验室质量控制规范食品理化检测》中实验室质量控制规范.扑草净的检出限(LOD,S/N≥3)和定量限(LOQ,S/N≥10)分别为5和10μg·kg-1.该方法简单、快速、灵敏、净化效果好,能满足水产品中扑草净残留的检测需求.

建立了水产品中5种硝基咪唑类药物(洛硝唑、甲硝唑、异丙硝唑、地美硝唑、氯甲硝咪唑)残留量的超高效液相色谱-串联质谱测定方法.样品经乙酸铵缓冲液分散后,用0.1％氨水乙腈超声提取,提取液经PRiME HLB小柱及PSA吸附剂净化后,UPLC-MS/MS检测,基质匹配标准曲线内标法定量.结果表明,水产品中5种硝基咪唑类药物的平均回收率在83.5％～110.3％之间,相对标准偏差在1.9％～12％之间,在0.5～10 ng/mL线性范围内,线性相关系数(r2)均大于0.997,检出限为0.5μg/kg,定量限为1.5 μg/kg.该方法能满足水产品中硝基咪唑类残留的检测需求.