Determination of glycarbylamide residues in chicken tissues by HPLC with post-column reaction

A newly developed HPLC method for determination of glycarbylamide (GB) in chicken liver was applied to other tissues (muscle, fat and kidney). The recoveries of GB in muscle, fat and kidney were 87.2% (CV 0.5), 91.3% (CV 4.7), 79.7% (CV 1.0), respectively. The detection limit of GB was 0.01 ppm. GB concentrations were determined by this method in tissues (muscle, fat, liver and kidney) from chickens sacrificed 5 days after oral administration of GB mixed in feed at 60 mg/kg of feed for 7 days. GB was not detected in these chicken tissues.     

A simplified method for the determination of several fish drugs in edible fish and shrimp by high-performance liquid chromatography

A simplified HPLC method was used to recover antibiotic and antibacterial agents from 11 cultured fish and one shrimp. The average recoveries of oxytetracycline, oxolinic acid, miloxacin, and sulfamonomethoxine were 77, 92, 89 and 80%, respectively. The detection limit was 0.02–0.04 μg/g. We also examined the recovery of oxytetracycline and oxolinic acid used for cultured black tiger shrimp, which is a popular imported shrimp in Japan. To demonstrate the usefulness of this technique for detecting drug residues in cultured fish, the method was used to examine the muscle tissues of 12 commercial fish and shrimp obtained from several fish shops. No agents were found in any of the fish tested.     

同时检测淡水鱼加工中土霉素和微囊藻毒素(MC-LR)残留量

目的:土霉素是限制我国淡水鱼深加工产品出口的关键抗生素之一;此外,由于水污染加重,淡水鱼中藻毒素残留问题也很严重。研究和开发同时快速检测技术已成为当前急需解决的问题。方法:鲫鱼鱼肉进行不同前处理,利用高效液相色谱测定毒素残留量。结果:土霉素和微囊藻毒素的最低检测限分别为0.1μg/kg、5ng/L。质量浓度范围0.1⁵.0μg/mL的土霉素、微囊藻毒素标准品制备标准曲线,线性关系较好,相关系数分别为0.995、0.998。精密度分别为1.82%、1.68%;回收率范围分别88.1%5.0μg/mL的土霉素、微囊藻毒素标准品制备标准曲线,线性关系较好,相关系数分别为0.995、0.998。精密度分别为1.82%、1.68%;回收率范围分别88.1%¹02.8%、90.6%102.8%、90.6%¹05%。结论:对比酶联免疫反应试剂盒的检测,2种方法结果没有太大差别。     

Tissue distribution and residue depletion of metronidazole in rainbow trout (Oncorhynchus mykiss)

Tissue distribution and residue depletion of metronidazole (MNZ) was studied in rainbow trout (Oncorhynchus mykiss) following oral administration of MNZ in feed at the average dose of 25 mg kg^?1 body weight day^?1 for 7 days at 11 ± 2°C. The MNZ concentration in feed was 0.25% while daily feed intake was 1% of body weight. The concentrations of MNZ and its main metabolite, hydroxymetronidazole (MNZOH), in fish tissues were determined by LC-MS/MS. The drug was well distributed in tissues with maximum concentrations on day 1 post-administration. At this time, the mean MNZ concentrations in muscle, skin, kidney, liver and gill were 14 999, 20 269, 15 070, 10 102 and 16 467 µg kg^?1 respectively. MNZ was converted into MNZOH with the ratio of MNZOH:MNZ up to 7% in all fish tissues throughout the withdrawal period. This shows that MNZ itself is the main residue in rainbow trout. MNZ was detected at the level close to the decision limit (0.20 µg kg^?1) in muscle, skin and muscle with adhering skin up to 42 days, while in kidney, liver and gill it was up to 28 days post-administration. MNZOH was eliminated more rapidly from fish tissues and it was present in muscle alone up to 21 days. The elimination half-lives of MNZ and MNZOH in rainbow trout tissues were 1.83–2.53 and 1.24–2.12 days, respectively. When muscle without skin was analysed, higher MNZ and MNZOH concentrations were detected, and for a longer period of time, than in muscle with adhering skin. Thus muscle alone could be more appropriate for the effective residue control of MNZ in rainbow trout. For the same reason, it is also essential to ensure direct cooling immediately after sampling, since MNZ and its metabolite degrade in fish muscle and skin stored in non-freezing conditions.     

Tissue distribution and depuration of 4-tert-octylphenol residues in the cyprinid fish,Scardinius erythrophthalmus

Alkylphenols are present in the aquatic environment through the degradation of alkylphenolpolyethoxylate surfactants in sewage treatment works. Branched chain 4-alkylphenols have been shown to retard testicular growth and stimulate vitellogenin synthesis in freshwater fish. We conducted in vivo studies in order to determine the fate and persistence of radiolabeled 4-tert-octylphenol (tOP) in the cyprinid fish, rudd (Scardinius erythrophthalmus). Sexually mature rudd were exposed to a concentration of 4.7 microg/L of [14C] tOP in a flow through system for 10 days. Radioactive residues were extracted from soft tissues and analyzed by radio-high-performance liquid chromatography. tOP accumulated as the major residue in muscle, ovary, and testis with bioconcentration factors of 24, 85, and 169, respectively. tOP residues in blood, gill, kidney, liver, and bile were extensively metabolized. Analysis of tOP residues in bile revealed 10 major metabolites, which were identified by GC-MS as products of aromatic and aliphatic hydroxylation, glucuronidation, and glucosidation. Depuration studies with exposed fish placed in clean water for up to 10 days resulted in a rapid loss of soluble residues from the tissues with half-lives of between 0.7 and 1.0 days (muscle, testis, ovary, gill, blood, kidney), 1.7 days (liver), and 5.9 days (bile). A further portion of radioactive residues was extracted from blood, gill, kidney, and liver after alkaline digestion, suggesting the formation of covalently bound protein adducts in these tissues. This study suggests that although para-alkyphenolic xenoestrogens can accumulate in muscle and the gonads of adult fish, residues are rapidly depurated from these tissues. Furthermore, analysis of the parent alkylphenol in bile, after hydrolysis of the conjugates, is likely to significantly underestimate the total concentration of alkylphenol residues and may not serve as an appropriate biomarker for quantifying the exposure of wild fish to alkylphenols.     

Analysis of trace residues of tetracyclines in animal tissues and fluids using metal chelate affinity chromatography/HPLC

A novel method of analysis for the trace residue determination of tetracyclines in animal tissues and fluids has been developed. Clean-up of sample extracts is based upon the specific ability of tetracyclines to chelate with divalent metal ions (metal chelate affinity chromatography, MCAC) and determination made by high-performance liquid chromatography. The method has been tested for the determination of oxytetracycline (OTC), tetracycline (TC) and chlortetracycline (CTC) in porcine kidney and muscle, ovine kidney, bovine kidney and milk, and trout muscle. Recoveries at the 0.05 mg/kg level for OTC, TC and CTC respectively were 75%, 63%, 73% in porcine kidney, 77%, 79%, 76% in porcine muscle, 85%, 54%, 53% in bovine kidney, 78%, 63%, 57% in ovine kidney, 75%, 58%, 56% in fish (trout) muscle, and 80%, 59%, 59% in bovine milk. At this level both within- and between-batch precision, as measured by the coefficient of variation (CV), was less than 10%. Determination to the 0.01 mg/kg level was carried out in all cases, although the method becomes less precise. The method has been used for several months and found to be both reliable and sufficiently rapid for use as a routine quantitative screening procedure. When coupled with liquid chromatography-mass spectrometry (LC-MS) it is suitable for use as a confirmatory method. Analysis of animals treated with tetracyclines has been carried out.     

磺胺甲噁唑和磺胺嘧啶在青石斑鱼组织中的分布及代谢规律

通过一次性投喂各含有200 mg/kg磺胺甲噁唑（sulfamethoxazole,SMZ）和磺胺嘧啶（sulfadiazine,SDZ）的饲料,研究两种药物在青石斑鱼中各组织分布与消除规律。采用超高效液相色谱-串联质谱检测青石斑鱼各组织中SMZ和SDZ的含量,并用内标法定量。结果表明,SMZ在青石斑鱼各组织中的最大含量：肝脏、背肌、血浆、肾脏和鳃依次为827.97μg/kg、776.70μg/kg、610.29μg/L、432.14μg/kg和345.18μg/kg。SDZ在青石斑鱼各组织中的最大含量：肝脏、背肌、鳃、血浆和肾脏依次为895.30μg/kg、660.55μg/kg、431.88μg/kg、419.56μg/L和310.67μg/kg。SMZ在青石斑鱼各组织中的半衰期：肾脏、鳃、背肌、血浆和肝脏半衰期依次为26.65、21.00、20.38、18.73h和16.90h。SDZ在青石斑鱼各组织中的半衰期：肾脏、血浆、鳃、背肌和肝脏依次为31.50、27.72、24.75、21.66h和18.24h。SMZ和SDZ在青石斑鱼肝脏中半衰期最短,代谢速度最快;在肾脏中半衰期最长,代谢速度最慢。在水温（25±2）℃条件下,SMZ和SDZ各200mg/kg的剂量同时单次投喂青石斑鱼,建议休药期不低于3d。SMZ和SDZ代谢规律研究为磺胺类药物在水产品中的合理使用提供了参考。     

Hexabromocyclododecane in marine species from the Western Scheldt Estuary: diastereoisomer- and enantiomer-specific accumulation

Hexabromocyclododecane (HBCD) is a widely used brominated flame retardant, which is increasingly reported in the environment. Here, we report on the diastereomeric and, for the first time, on the enantiomeric composition of HBCD in muscle and liver of several fish species caught in the Western Scheldt Estuary (The Netherlands). The total HBCD content (sum of alpha-, beta-, and gamma-diastereoisomers), as well as the distribution of diastereoisomers and enantiomers, varied between the species. The levels of total HBCD (9-1110 ng/g lipid weight) found in fish tissues were higher than those measured in fish from European rivers with no known point sources of HBCD but lower than in fish samples collected near factories producing or using HBCD. The concentrations of total HBCD expressed on a lipid weight basis were higher in liver than in muscle for bib and whiting, while in sole, HBCD had no preferential distribution between the tissues. A similar pattern for liver and muscle distribution was already observed for polybrominated diphenyl ethers (PBDEs) in these species. The alpha-HBCD diastereoisomer was most abundant in all fish samples with a higher contribution to the total HBCD levels in liver compared to muscle for bib and whiting. The gamma-HBCD diastereoisomer accumulated less in liver than in muscle of sole, bib, and whiting. For the first time, enantiomer fractions were determined for HBCD diastereoisomers in liver of three fish species and in muscle of two fish species. A significant enrichment of the (+) alpha-HBCD enantiomer was found in whiting and bib liver samples. A high enantioselectivity has also been seen for the gamma-HBCD diastereoisomer in whiting liver.     

Distribution and residue depletion of oxytetracycline in giant freshwater prawn (Macrobrachium rosenbergii)

Distribution and residue depletion patterns of oxytetracycline were examined in giant freshwater prawns, Macrobrachium rosenbergii, after medicated-feed treatment at the feeding level of 4 g/kg of feed for 5 consecutive days. The concentration of oxytetracycline in prawn muscle tissues was measured using high-performance liquid chromatography equipped with a fluorescence detector. The limit of detection was 0.1 microg/g. In the medicated-feed-treated group, oxytetracycline was detectable 8 days posttreatment at the feeding level of 4 g/kg of feed for 5 consecutive days. The depletion half-life and mean residence time of oxytetracycline were 30.96 and 100.3 h, respectively. The dose of 4 g/kg of feed for 5 consecutive days can be recommended for therapeutic dosage regimen in giant freshwater prawn aquaculture. The minimal withdrawal period of M. rosenbergii muscle tissue should be 8 days postcessation of medicated feed.     

EFFECT OF FOOD-PROCESSING METHODS UPON SURVIVAL OF THE TREMATODE HETEROPHYES SP. IN FLESH OF MULLET CAUGHT FROM BRACKISH EGYPTIAN WATERS

SUMMARY— Mullet caught from brackish-water lakes such as Manzala Lake in Egypt were found to serve as an intermediate host for Heterophyes parasite. Infection of man with this parasite may be very heavy. causing severe symptoms. This study revealed that some food-processing methods or treatments may not be adequate to kill the parasite in the fish muscle tissues. It was found that Heterophyes could survive for 30 hr when infected fish were stored at −10 or −20°C. Viability was greater, i.e., 9 days, when stored et refrigerator temperature of 6°C. On the other hand, when fish were dipped in chlortetracycline solution (30 pbm) for 2 hr, the parasite's viability was not affected. Moreover, ice treated with oxytetracycline used for fresh fish preservation had no marked influence on the viability of Heterophyes When infected fish were grilled in a manner quite similar to that adopted by Egyptian fisherman during their fishing trips, about 20-30% of the fish contained living metacercariee of Heterophyes owing to the insufficiency of the heat treatment. Further, in mullet kept at 50 and 100°C, the parasite lived for 180 and 10min. respectively. Thus, insufficient processing or treatment of brackish-water mullet does not completely destroy the parasite, thereby rendering such fish hazardous to the health of persons consuming them.     

Liquid chromatography-mass spectrometry method to detect Tetrodotoxin and Its analogues in the puffer fish Lagocephalus sceleratus (Gmelin, 1789) from European waters

The presence of tetrodotoxin (TTX) and its analogues, 4-epiTTX, 4,9-anhydroTTX, 5-deoxyTTX, 11-deoxyTTX, 5,6,11-trideoxyTTX, 11-norTTX-6(S)-ol, and 11-norTTX-6(R)-ol was investigated for the first time in five different tissues (liver, gonads, gastrointestinal tract, muscle, and skin) of six specimens of the marine puffer fish Lagocephalus sceleratus from European waters (Aegean Sea, Greece) by using liquid chromatography coupled to electrospray ionisation mass spectrometry operating in the conventional mode in addition to low-energy collision dissociation tandem mass spectrometry (CID-MS/MS).Two isomers of 5,6,11-trideoxyTTX were detected in all specimens as the major TTX analogues, followed by 11-deoxyTTX, 11-norTTX-6(S)-ol, and TTX. However, minor amounts of 4-epiTTX, 4,9-anhydroTTX, 5-deoxyTTX, and 11-norTTX-6(R)-ol were also found in most of the tested tissues. In all puffer fish specimens, gonads, gastrointestinal tract, and liver contained the highest toxin levels, whereas muscle and skin contained lower amounts. Toxin distribution within the tissues of the six L. sceleratus specimens was different depending on fish size, area, and season where fish were caught. The LC-ESI-CID-MS/MS analysis employed is proposed as a suitable technique for determination of TTX and its analogues with a low detection limit (0.08 μg/g).     

Residue analysis of spectinomycin in tissues of chicken and swine by HPLC

A reversed-phase HPLC method with ultraviolet detection using p-nitrophenyl hydrazine as a pre-column derivatizing reagent was investigated for the determination of the antibiotic spectinomycin (SPCM) in muscle, liver, kidney and fat of chicken and swine. SPCM was extracted from samples with 10% trichloroacetic acid saturated with EDTA-2Na, and then cleaned up with coupled Sep-Pak Plus PS-2 cartridges. The detection limit of SPCM was 0.02 microgram (potency)/g. Recoveries of SPCM ranged from 77.4 to 97.4% for chicken tissues and from 74.5 to 91.8% for swine tissues. The present method was used for the analysis of chicken tissues after the 11th day of withdrawal (SPCM-medicated drinking water: 500 mg (potency)/L, for 7 days), and swine tissues after the 14th day of withdrawal (SPCM-medicated feed: 100 mg (potency)/kg, for 7 days). Results showed that SPCM concentrations were lower than the MRLs in all tissues.     

Chloramphenicol and oxytetracycline residues in milk and tissues from cows and bullocks treated with an injectable formulation

A commercial formulation of chloramphenicol and oxytetracycline was administered to dairy cows and bullocks by the intramuscular route. Concentrations of drugs were determined in milk and edible tissues by high-performance liquid chromatographic and microbiological methods. The data allowed the calculation of withdrawal times for milk (4 and 17 milkings for chloramphenicol and oxytetracycline, respectively) and for tissues (35 days for chloramphenicol, more than 35 days for oxytetracycline, depending on the levels at the injection sites). Hence oxytetracycline residues were the most persistent in these types of foods, according to our dosage scheme.     

Oxytetracycline, Sulfadimethoxine, and Ormetoprim Residues in Channel Catfish by HPLC

HPLC methods and modified extraction procedures were used to analyze residues of oxytetracycline (Terramycin, OTC) or sulfadimethoxine (SDM) and ormetoprim (OMP) in channel catfish fed OTC or Romet-30 under controlled conditions. Mean recovery rates in fish muscle were 92.5% for OTC over concentrations of 0.05–1.0 ppm and 86.3% for OMP and 87.9% for SDM over 0.05–5.0 ppm. SDM and OMP were rapidly depleted from large catfish (about 345g) after 5 days feeding with Romet-30 at 50–100 mg/kg body weight. By day 2 post-treatment, no residue was detected. Residues of OTC, SDM and OMP were also detected in fingerling channel catfish (about 20.3g) after 4 and 8 wk of feeding with Romet-30 or OTC at 12.5, 25, or 50 mg/kg body weight, but not after a 3-wk-withdrawal period.     

Development of an HPLC–UV method for the simultaneous determination of tetracyclines in muscle and liver of porcine,chicken and bovine with accelerated solvent extraction

A simple and especially rapid method-using accelerated solvent extraction (ASE) and HPLC has been developed for the quantitative determination of oxytetracycline, tetracycline, chlortetracycline, minocycline, methacycline, demeclocycline and doxycycline in muscle and liver of porcine, chicken and bovine. Samples of muscle and liver were extracted with trichloracetic acid/acetonitrile using ASE instrument, parameters such as extraction temperature (40–80 °C) and pressure (45–85 bar) were investigated and the selected extraction (60 °C, 65 bar) was most effective. The limits of detection were lower than 10 μg/kg and limits of quantification no more than 15 μg/kg for all compounds in muscle and liver. The recoveries of tetracyclines spiked at levels of muscle 50–150 μg/kg, liver 150–450 μg/kg, averaged from 75.0% to 104.9% with the relative standard deviation values less than 10%. The method was applied to determine 30 real porcine livers. It is demonstrated that the new method is robust for detection and quantification of seven tetracycline residues in muscle and liver of porcine, chicken and bovine.     

Distribution and elimination of levamisole in eggs and tissues after oral administration to laying hens,determined by LC-MS/MS

Levamisole was administered to laying hens, and concentrations in eggs and tissues (thigh muscle, breast muscle, liver and kidney) were determined by a newly developed liquid chromatography tandem mass spectrometry method, which allowed trace level quantification of levamisole. The adopted analytical method showed good sensitivity, repeatability and percentage of recovery from spiked matrices. Maximum concentrations of levamisole were found on the first day after the administration (531.1 μg/kg in liver, 164.3 μg/kg in egg yolk, 130.7 μg/kg in kidney, 78.0 μg/kg in breast muscle, 70.7 μg/kg in thigh muscle and 64.0 μg/kg in egg white), after which there is a decline. The compound was rapidly eliminated from eggs, with a half-life of 1.3 days. Elimination appeared to be slower in thigh muscle (3.5 days), breast muscle (3.4 days) and liver (3.3 days). According to this experiment, the levamisole withdrawal periods calculated for eggs, liver, kidney, breast muscle and thigh muscle in laying hens were 14.1, 6.1, >4.0, 14.5 and 13.0 days, respectively. The longest time for levamisole residues to be completely released from tissues was seen in liver samples (37.4 days), followed by thigh muscle, breast muscle and kidney. Elimination from eggs was fastest (16.4 days for levamisole residues to drop below the method quantification limit).     

Simultaneous Determination by HPLC of Fat-Soluble Vitamins in Albacore (Thunnus alalunga)

The fat-soluble vitamins A, D and E were determined by a liquid chromatographic method. The vitamins were extracted from the tissues with chloroform and methanol, saponified and separated on a Lichrosorb normal phase column followed by UV detection. Recoveries of added vitamins in liver samples were 93.0% for vitamin A, 90.0% for vitamin D and 92.1% for vitamin E. The results from a study of fat-soluble vitamins in samples of albacore showed that the vitamin A and D were found only in fish liver and vitamin E was found in the liver and the edible muscle.     

卵形鲳鲹不同组织器官脂肪酸组成含量的比较

取卵形鲳鲹白色肌肉、红色肌肉、肝脏和脾脏,用气相色谱- 质谱(GC-MS)联用分析仪分析各组织器官脂肪酸组成。结果共鉴定出23 种主要脂肪酸,同组织雌雄间总脂及脂肪酸组成无明显差异,不同组织间差异明显;肝脏中总脂含量最高,白色肌肉中总脂含量最低;脾脏、白色肌肉中含有丰富的高度不饱和脂肪酸,有较高的食用价值,而肝脏中含有高比例的饱和脂肪酸和单不饱和脂肪酸,多不饱和脂肪酸含量较低,是鱼体内重要的储能器官。     

Effects of extraction and spiking procedures on the determination of incurred residues of oxytetracycline in cattle kidney.

The effects of different extraction and spiking procedures on the determination of incurred oxytetracycline residues in animal tissues have been investigated. The extraction procedures investigated--direct aqueous or organic solvent extraction, enzymic digestion or sonication--all gave similar results for incurred oxytetracycline concentration in cattle kidney after correction for spike recovery. There was therefore no evidence for binding or conjugation of oxytetracycline in this tissue. Highest recovery from spiked tissue was obtained using ethyl acetate as extractant. The effects of spiking procedure (spike contact time, spike solvent and tissue state) on recovery from spiked cattle kidney were also small, indicating that added oxytetracycline spike does not interact with the tissue.     

Essential elements and contaminants in tissues of commercial pelagic fish from the Eastern Mediterranean Sea

BACKGROUND: It is important to determine the concentrations of essential and non‐essential metals in fish for human health. The essential elements and contaminants (Pb and Cd) were determined seasonally in the muscle and liver of some pelagic fish species round herring (Etrumeus teres), chub mackerel (Scomber japonicus), golden grey mullet (Liza aurata) and Mediterranean horse mackerel (Trachurus mediterraneus) from the Iskenderun Bay, Eastern Mediterranean Sea. RESULTS: The Na, K, Ca and Mg were the most abundant elements in muscle and liver tissues. The Na, K, Ca and Mg concentrations in fish tissues were between 51.7 and 3426 mg kg^?1. Muscle accumulated the lowest levels of elements. Trace element and contaminant levels in muscle were highest in spring and summer. The Cu, Zn and Cr concentrations were highest in summer. The Ni, Mn and Fe concentrations were highest in spring. The maximum Pb concentrations in the muscle and liver of fish species was 0.39 and 0.80 mg kg^?1 in autumn. The maximum Cd concentration in the muscle of fish was 0.27 mg kg^?1 in spring and the maximum Cd concentration in the liver was 0.78 mg kg^?1 in summer. CONCLUSION: The Cr, Pb, Cd, Cu and Zn levels in muscle were found to be lower than permissible limits reported by various authorities. Estimated weekly and daily intake for Pb and Cd by consumption of fish muscle were far below the PTWI and PTDI values established by FAO/WHO. Copyright © 2009 Society of Chemical Industry