Assessment of Mercury Concentrations in Water and Fish Tissue Analysis in Kaw Lake, Oklahoma, 2022

The Kaw Nation has been collecting water, sediment, and fish samples from Kaw Lake and upper Arkansas River from 2007 to present to examine the concentrations of Mercury and other heavy metals to protect the health of the tribal members. Kaw Lake is in the North-Central part of Oklahoma. Kaw Lake is a permanent water body constructed in 1976 by the Army of Corps of Engineers. The Lake is consistently fed by the Arkansas River and other tributaries as runoff coming all the way from Colorado through Kansas to Kaw Lake of Oklahoma. The Lake has a surface area of 26.64 square miles (69 km2) and shoreline of 168 miles (270 km) with a total drainage area of 56,345 square miles (145,393 km2) and an average water depth of 8 meters. The water and fish samples were collected from 7 sites of Kaw Lake, once in a month and the fish samples once in a year during summertime, early July to end of July. The fish samples focused on 5 sport, predator, and bottom dwelling species of large consumable size, greater than 200 mm length and 560 grams weight. The five fish sampled were Catfish, White bass, Largemouth and Smallmouth bass, Black and White crappie. The fish and water samples were sent to Accurate Environmental Labs for detailed analysis. Predator species were analyzed as fillet and the bottom dwellings as a whole fish using EPA Method 7471A-M. Mercury from Water and Fish Tissue Samples were analyzed by Atomic Fluorescence Spectrometry. The laboratory analysis indicated that all the Mercury concentration in the fish samples except in Blue Catfish and Spotted Bass fall below the Maximum Contaminant Level (MCL) of 0.5 mg/kg.

Determination of Steroid Hormone Residues in Fish Tissues Using Gel Permeation Chromatography and Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

A highly sensitive method was developed for the simultaneous determination of 8 steroid hormones in high-fat fish tissues using ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).The 8 steroid hormones were extracted from the tissues with diethyl ether.Differing from other common purification methods,the extract solutions were cleaned by gel permeation chromatography(GPC) using ethyl acetate-cyclohexane solution(1:1,v/v) as the mobile phase.The separation of target compounds was carried out by a BEH C18 column and a gradient elution consisting of acetonitrile and 0.2% aqueous formic acid(v/v).The compounds were detected under the multiple reaction monitoring(MRM) mode and quantified with external standard method.This method was validated with respect to linearity,specificity,accuracy and precision.A linearity with correlation coefficient larger than 0.995 was achieved in the range of 0.5 to 50 ng m L^(-1).The average recoveries at the spiked levels of 1.0,5.0,and 10.0 μg kg^(–1) varied between 81.7% and 90.8%,with the relative standard deviations(n=5) ranged from 3.50% to 10.0%.The limit of quantification(LOQ) for 8 steroid hormones ranged from 0.2 to 1.5 μg kg^(-1).It was concluded that this method can be successfully applied for the determination of 8 steroid hormones in complicated matrices including high-fat fish tissues.

Diethylstilbestrol in Fish Tissue Determined Through Subcritical Fluid Extraction and with GC-MS

As the key point in sex hormone analysis, sample pre-treatment technology has attracted scientists' attention all over the world, and the development trend of sample preparation forwarded to faster and more efficient technologies. Taking economic and environmental concerns into account, subcritical fluid extraction as a faster and more efficient method has stood out as a sample pre-treatment technology. This new extraction technology can overcome the shortcomings of supercritical fluid and achieve higher extraction efficiency at relatively low pressures and temperatures. In this experiment, a simple, sensitive and efficient method has been developed for the determination of diethylstilbestrol(DES) in fish tissue using subcritical 1,1,1,2-tetrafluoroethane(R134a) extraction in combination with gas chromatography-mass spectrometry(GC-MS). After extraction, freezing-lipid filtration was utilized to remove fatty co-extract. Further purification steps were performed with C_(18) and NH_2 solid phase extraction(SPE). Finally, the analyte was derived by heptafluorobutyric anhydride(HFBA), followed by GC-MS analysis. Response surface methodology(RSM) was employed to optimizing the extraction condition, and the optimized was as follows: extraction pressure, 4.3 MPa; extraction temperature, 26℃; amount of co-solvent volume, 4.7 m L. Under this condition, at a spiked level of 1, 5, 10 μg kg^(-1), the mean recovery of DES was more than 90% with relative standard deviations(RSDs) less than 10%. Finally, the developed method has been successfully used to analyzing the real samples.

Total Reflection X-Ray Fluorescence Analysis of Toxic Metals in Fish Tissues

The concentration of Cr, Ni, Cu, Zn, Hg and Pb, considered like toxic, was evaluated in fish tissues by means the total reflection X-Ray Fluorescence technique (TXRF). Grass carp (Ctenopharygodon idella) samples were collected from six regions of the Tepuxtepec Dam which was used as a water reservoir and fish production for the local population. Fish tissues: gills, liver, kidney and muscle were analyzed in triplicate using a TXRF spectrometer “TX-2000 Ital Structures” with a Si(Li) detector and a resolution of 140 eV (FWHM) at Mn Kα and Mo tube (40 kV, 30 mA) with 17.4 KeV excitation energy. The mean concentration of metals in tissues decrease in the sequence: Kidney ≈ Gills > Liver > Muscle;the range of concentration for Zn was 26.68 - 816.67 mg/Kg followed by Cu: 1.18 - 35.81 mg/Kg, Cr: 1.10 - 9.30 mg/Kg, Ni: 0.40 - 3.80 mg/Kg, Pb: <0.02 - 1.92 mg/Kg and Hg: <0.03 - 1.97 mg/Kg. Chromium and mercury concentrations slightly exceed the limits for fish proposed by FAO/WHO and Mexican Legislation for human consumption in the edible parts of fish from each one of the regions of the Tepuxtepec Dam. The results show that metal accumulation in herbivorous carp tissues was higher in regions 1, 2 and 3 than the others, which could be due to the influence of Lerma River, one of the most polluted rivers of Mexico.

Development of An Enzyme-Linked Immunosorbent Assay for Determination of the Furaltadone Etabolite,3-Amino-5-Morpholinomethyl-2-Oxazolidinone(AMOZ) in Animal Tissues

Objective To determine 3-amino-5-morpholinomethyl-2-oxazolidinone （AMOZ） residues released from protein bound AMOZ in animal tissues. Methods Polyclonal and monoclonal antibodies were produced in this study. A rapid, sensitive, and specific competitive direct enzyme-linked immunosorbent assay （cdELISA） was developed. Results Rabbit polyclonal antibodies were used in the optimized cdELISA method, and exhibited negligible cross-reactivity with other compounds structurally related to AMOZ. The IC50 of the polycional antibody was 0.16 ng/mL The method limit of detection in four different types of animal and fish tissues was less than 0.06 μg/kg. Recoveries ranged from 80% to 220% for fortified samples with the coefficient of variation values less than 15%. The results of the cdELISA method were in good agreement with the results from an established liquid chromatography-tandem mass spectrometry confirmatory method used for AMOZ residues. Conclusion The cdELISA method developed in the present study is a convenient practical tool for screening large numbers of animal and fish tissue samples for the the detection of released protein bound AMOZ residues.

加速溶剂萃取-FMS净化-高分辨气相色谱-高分辨质谱(HRGC-HRMS)定量测定鱼组织中二噁英类多氯联苯

A rapid,sensitive and accurate method has been developed for the determination of twelve dioxin-like polychlorinated biphenyls(PCBs) in fish tissue using isotope dilution high resolution gas chromatography-high resolution mass spectrometry (HRGC-HRMS).Dioxin-like PCBs was extracted from samples by Accelerated Solution Extraction (ASE) and purified by Fluid Management Systems (FMS).Confirmation and quantitative analysis at pg/g level of PCBs was performed by HRGC-HRMS using voltage selective ion record(VSIR)mode.The recoveries of twelve isotopically labeled compound solution were found to be in the range of 64.9%-103.8%.The quantitative detection limits of the method for dioxin-like PCBs are 0.1 pg/g.This method not only meets the requirements of international standard,but also shortens the analysis time from a period of 2 weeks to 2 days.

Analysis of monomeric and oligomeric organophosphorus flame retardants in fish muscle tissues using liquid chromatographyeelectrospray ionization tandem mass spectrometry:Application to Nile tilapia(Oreochromis niloticus)from an e-waste processing area in northern Vietnam

Using electrospray ionization tandem mass spectrometry combined with liquid chromatography(LC),a novel analytical method was developed to quantify eight monomeric organophosphorus flame retardants(m-PFRs)and three oligomeric organophosphorus flame retardants(o-PFRs)in fish muscle samples.The optimization and validation experiments indicate that the developed method can determine accurately the concentrations of analytes in fish muscle samples.The recoveries of analytes in fish muscle samples were in the range of 74-105%.The coefficients of variation of the concentrations of analytes in fish muscle samples were 0.6-8.9%.The concentrations of analytes in procedural blanks were below the limit of quantification(LOQ)values.Furthermore,the developed method was applied to the analysis of m-PFRs and o-PFRs in the muscle samples of tilapias collected from an electronic waste(ewaste)processing area in northern Vietnam.The concentrations of m-PFRs such as tris(2-chloroethyl)phosphate(TCEP),tris(2-chloroisopropyl)phosphate(TCIPP),and triphenyl phosphate(TPHP)were dominant among the investigated m-PFRs.The respective concentrations of TCEP,TCIPP,and TPHP were up to 160,300,and 230 ng g^-1 lipid weight,respectively,whereas those of o-PFRs were up to 10 ng g^-1 lipid weight.The results of this study indicate lower accumulation potential of o-PFRs compared with m-PFRs for the first time.