Gaschromatographische Analysenmethode für Rückst?nde von sieben Penicillinen in Lebensmitteln tierischen Ursprungs

Zusammenfassung Beschrieben wird ein capillargaschromatographisches Verfahren, mit dem sich Rückstände von Benzylpenicillin, Phenoxymethylpenicillin, Methicillin, Oxacillin, Cloxacillin, Dicloxacillin und Nafcillin in Muskelfleisch, Leber, Niere und Fettgewebe vom Rind sowie in Milch bestimmen lassen. Die Proben werden unter schwach sauren Bedingungen mit Acetonitril extrahiert und das mitextrahierte Wasser nachfolgend durch Aussalzen entfernt. Der Rohextrakt wird anschließend durch Flüssig/Flüssig-Verteilung sowie durch Anionenaustausch an einer Festphasenkartusche gereinigt. Nach Methylierung mit Diazomethan müssen nur die Extrakte aus Leber und Niere zusätzlich noch an einer Diol-Kartusche gereinigt werden. Die gaschromatographische Bestimmung beruht auf einer split/splitless Injektion mit Hilfe eines temperaturprogrammierbaren Injektors, Trennung an einer unpolaren Methylsiliconphase und Detektion mittels eines thermionischen Stickstoffdetektors. Die Auswertung erfolgt gegen einen internen Standard. Die Nachweisgrenzen liegen bei allen Wirkstoffen und Substraten unterhalb von 3 g/kg. Die Ausbeuten bei Zusatzversuchen im Konzentrationsbereich von 3–10 g/kg liegen bei Milch zwischen 65 und 80% und bei tierischen Geweben meistens zwischen 50 und 70%.

---

Gas chromatographic method for the determination of residues of seven penicillins in foodstuffs of animal origin

Summary A capillary gas Chromatographie method is described for the determination of residues of benzylpenicillin, phenoxymethylpanicillin, methicillin, oxacillin, cloxacillin, dicloxacillin and nafcillin in bovine muscle, liver, kidney, adipose tissue and milk. The samples are extracted with acetonitrile under slightly acidic conditions, the co-extracted water is separated with the addition of sodium chloride and dichloromethane and discarded. Clean-up is performed by liquid/liquid partitioning steps and anion exchange chromatography. The penicillin residues are methylated with diazomethane. After derivatization, only the extracts from liver and kidney needed further clean-up using cartridges with a polar diol sorbent. The gas Chromatographic procedure is based on split/splitless injection, programmed temperature vaporization, separation on a methyl silicone fused silica column and nitrogen-specific thermionic detection. Internal standardization is used for quantification. The limits of detection for all penicillins are well below 3 g/kg in milk and all tissues. Recoveries of spiked samples at 3 and 10 g/kg are in the range of 65–80% for milk and 50–70% for bovine tissues.

     

Determination and depletion of dehydroacetic acid residue in chicken tissues

A high-performance liquid chromatography (HPLC) method was developed to determine dehydroacetic acid (DHA) residues in chicken muscle, liver and kidney. DHA was extracted using acetonitrile, and clean-up performed using a strong anion exchange (PAX) SPE column. The cleaned-up samples were separated by HPLC with a C18 column and determined at 290 nm. Extraction recoveries of DHA from samples fortified at 0.5-5 mg/kg levels ranged from 88.2% to 93.9% in muscle, 83.8% to 86.6% in liver and 83.8% to 89.8% in kidney, with coefficients of variation <6.44%. The limit of detection was 0.05 mg/kg and limit of quantification was 0.2 mg/kg. DHA was not detectable in muscle at 13-15 days after final administration of DHA, at 11 days in kidney and 17 days in liver. The method described herein is suitable for routine quantitative analyses of DHA in animal tissues and can be easily applied to the analysis of other matrices such as milk, serum and tissue samples from other animals.     

Chemical analysis of veterinary drugs in food. 1. General methods and gas chromatographic procedures

A review is presented that in the first section describes current techniques for preparation, extraction and clean up of food samples for the determination of veterinary drug residues by chemical methods. The second section gives an overview of gas chromatographic methods published up to 1983 for the analysis of meat, liver, kidney, egg and milk for residues of antibiotics and chemotherapeutic agents. Discussed are stability of the compounds, derivatization, detection and particular aspects of their metabolism. The structural formula is given for all drugs mentioned. The procedures for determination are summarized in a table, together with the most important analytical parameters.     

Determination of β-lactam residues in foodstuffs of animal origin using supported liquid membrane extraction and liquid chromatography–mass spectrometry

β-Lactams have been used extensively both in human and veterinary medicine practices. In veterinary medicine, they are used mainly as growth promoters as well as chemotherapeutic and prophylactic agents. The occurrence of β-lactam residues in foodstuffs is a serious health hazard. In this work, a sample purification and enrichment technique involving the use of supported liquid membrane have been developed for β-lactams in milk, kidney and liver tissues. The liquid membrane made of n-undecane:di-n-hexyl ether (1:1) was used to enrich a mixture of four β-lactams namely, ampicillin, cloxacillin, penicillin V and penicillin G. Separation and detection of the enriched β-lactam extracts were performed using a high performance liquid chromatography coupled to a mass spectrometer operating under positive ion electrospray mode (LC–PI–ESI–MS). The detection limits (DLs) obtained were found to be 1 ng/kg for penicillin G and penicillin V in kidney and liver tissues and 0.7 μg/L in milk. For ampicillin, the DLs were found to be 1.4 μg/kg in kidney and liver tissues and 1.7 μg/L in milk. Limits of quantification based on a minimal value of the signal-to-noise ratio of 10, were estimated to be 1.1 and 0.01 for penicillin G in kidney and liver tissues, respectively, while for penicillin V it was 0.4 and 0.01 for kidney and liver tissues, respectively. The DL values obtained using this approach were found to be 2–3 order of magnitudes lower than the stipulated tolerance levels as set by the EU and FDA.     

Simultaneous determination of chloramphenicol and florfenicol in liquid milk, milk powder and bovine muscle by LC-MS/MS

A validated method based on European and Brazilian legislation is reported. It is applicable to the simultaneous determination of chloramphenicol (CAP) and florfenicol (FF) by LC-MS/MS in liquid milk, milk powder and bovine muscle. The chromatographic analysis is completed in 6 min and the extraction procedure is very simple, involving only one step liquid-extraction with ethyl acetate. Where it proved necessary to include clean-up, an efficient and rapid step using C18-dispersive solid was added. Initially, a complete validation was performed with liquid milk matrix; later the scope was extended to the other matrices through extending the inter-day precision (within laboratory reproducibility) RSD values. An internal standard (d(5)-CAP) was employed for quantitative purposes. The method was shown to have good accuracy and precision for determining CAP residues at the level of 0.3-0.6 g kg(-1) and FF residues at the level of 5-15 μg kg(-1).     

Analysis and monitoring of chloramphenicol residues in food of animal origin in Slovenia from 1991 to 2000

To prevent the illegal use of chloramphenicol (CAP), regulatory control of its residues in food of animal origin is essential. In Slovenia, the monitoring of CAP residues for statutory purpose started in 1991. The results of a 10-year period are presented. CAP residues were determined by capillary gas chromatography (GC) with electron capture detection (ECD) using meta-CAP as an internal standard (ISTD). Before chromatographic determination, analytes were derivatized by silylation. Overall, CAP recovery, adjusted for ISTD, was for bovine muscle tissue and raw cow's milk (in the region of 2-10 μg kg^-1) 89 and 102%, respectively, and for whole eggs, 87% (in the region of 1-10 μg kg^-1). The use of meta-CAP improved significantly the precision of the method. The detection limit for CAP was 1 μg kg^-1, which was sufficiently sensitive for routine use. A total of 1308 random samples of Slovenian origin were analysed from 1991 to 2000, covering all parts of the country. CAP was found only in one milk sample in 1997 at a concentration of 4.6 μg kg^-1.     

Lead, cadmium, arsenic and mercury in meat, liver and kidney of Swedish pigs and cattle in 1984-88

During the period 1984-88 several hundred samples of meat, liver and kidney from Swedish pigs and cattle were analysed for lead, cadmium, arsenic and mercury. Analysis was performed by AAS and extensive quality assurance was carried out. The mean lead levels in pig meat, liver and kidney were less than 0.005, 0.019 and 0.016 mg/kg, respectively: the mean levels in the corresponding bovine tissues were less than 0.005, 0.047 and 0.097 mg/kg. The mean cadmium levels in pig meat, liver and kidney were 0.001, 0.019 and 0.11 mg/kg, whilst those in the corresponding bovine tissues were 0.001, 0.070 and 0.39 mg/kg. The mean arsenic levels in pig meat, liver and kidney were 0.024, 0.023 and 0.019, respectively and those in the corresponding bovine tissues were lower, none exceeding 0.015 mg/kg. The mean mercury levels in pig meat, liver and kidney were 0.009, 0.015 and 0.019 mg/kg respectively, while those in the corresponding bovine tissues were 0.005, 0.006 and 0.010 mg/kg. A decrease in the levels of both arsenic and mercury in pig tissues was found during the period studied, which may be due to a decrease in the use of fish meal in pig feed.     

A method for the analysis of lincomycin in porcine and bovine kidney

A method of analysis has been developed for the estimation of lincomycin in porcine and bovine kidney. The method employed high performance liquid chromatography and Sep-Pak clean-up of methanolic tissue extracts and nitrogen specific gas chromatographic detection. Using spiked (0.1 mg kg-1) extracts recoveries in the range 40-50% were obtained. Analysis at the 0.05 mg kg-1 level is possible. Fifty four samples of kidney destined for UK sale were analysed for the presence of this drug. No samples were found to contain lincomycin.     

QuEChERS-高效液相色谱法检测不同畜禽产品中5种氟喹诺酮类的药物残留

目的 建立QuEChERS法检测多种畜禽产品中5种氟喹诺酮类药物残留.方法 采用酸化的乙腈溶液提取猪、牛、羊、鸡和鸭等畜禽的肌肉、皮脂、脂肪、肝和肾组织中氟喹诺酮类残留,用微型高速分散机在离心管内同时完成均质与提取,采用增强型脂质去除过滤柱对提取物进行2次洗脱,用高效液相色谱-可变波长荧光检测器法检测.结果 达氟沙星和...     

Occurrence of endosulphan residues in dairy milk in plains of Uttarakhand,India: Short communication

Endosulphan residues were determined in milk samples collected from various locations of plains of Uttarakhand covering Tarai and Kumaon regions. Residues were extracted from milk by liquid–liquid partition followed by clean‐up by alumina column chromatography. High‐performance liquid chromatography (HPLC) was used for the detection and quantification of residues. Of the total 170 milk samples collected from different species, 1.17% samples showed residues of endosulphan‐alpha; 2.35% endosulphan β and 4.7% milk samples showed endosulphan‐sulphate residues with mean residual concentrations of 0.244, 0.566 and 0.265 μg/mL, respectively. About 6.47% of milk samples showed endosulphan residues above the maximum residue limit (MRL) of 0.1 mg/kg.     

高效液相色谱法测定液态乳中乳果糖方法的优化

为了对液态乳中乳果糖含量进行简便准确地定量,改进高效液相色谱法测定乳果糖含量的方法。采用化学稳定的改性酰胺基色谱柱进行分离,并以乙腈-水流动相梯度洗脱40 min,结果表明,样品进样体积为3 μL时乳糖与乳果糖的分离度为1.5,满足色谱分离检测。优化后的方法经验证,乳果糖在50~2500 mg/kg范围内线性关系良好,（R2=0.9997）,乳果糖检出限和定量限分别为15和50 mg/kg,3个加标水平（n=6）乳果糖平均回收率在90.3%~105.6%之间,相对标准偏差为3.4%~3.9%。利用该法对市场中的27种实际乳样进行分析,结果均在合理范围之内。该方法经济、准确适用于液态乳中乳果糖含量的日常检测。     

Organochlorine content of milks, dairy products and animal feed ingredients: Ireland 1971-1972.

Milks (bovine and human) and dairy products (butter, cheese, skim and whey powders, calf-replacer, casein, butter-oil and dietetic food) were collected during 1971/2 throughout Ireland together with a more limited samples of the 10 major animal feed ingredients, and analysed for organochlorine insecticide residues using electron-capture gas chromatography. The different materials contained low or negligible levels of chlorinated insecticides. Apart from some of the animal feed ingredients the DDT residues were generally the predominant contaminants detected together with lower levels of gamma-BHC (lindane), aldrin/dieldrin and heptachlor/heptachlor epoxide. The maximum levels of these insecticides in the bovine milk and dairy products (511, 100, 62 and 21 mug/kg fat respectively) constitute only 50% or less of the Codex Tolerance Limits. The correspondingly low residue levels in the human milk (maxima of 128, 1, 1, and 5 mug/kg fat respectively) which at most represent insecticidal ingestion by infants equivalent to 13, 0-05, 5 and 5% respectively of the WHO/FAO acceptable daily intake for DDE, gamma-BHC, aldrin/dieldrin and heptachlor/heptachlor epoxide again pose no obvious health hazards and are strongly indicative of negligible organochlorine contamination in the general diet. The samples of animal feed ingredients examined also contained trace levels of ogranochlorines (maxima of 0-9, 0-1, 1-6 and 1-0 mug/kg respectively). More extensive monitoring of the residues in animal feed ingredients (the most probable source of milk contamination is advocated, and the desirability of tolerance limits for insecticides in animal feeds discussed.     

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).     

优化气相色谱法检测牛奶中双甲脒残留标志物

目的改进国标中的气相色谱法测定牛乳中双甲脒残留标志物残留的前处理与色谱条件。方法样品使用1 mol/L的盐酸溶液提取,10000 r/min离心转速离心5 min,取上清液使用固相萃取(solid-phase extraction,SPE)小柱过滤净化。对气相色谱的色谱条件进行优化,使用外标法定量。结果通过使用优化处理条件,该方法的线性范围在10~400 ng/m L,线性关系良好。添加5、10、25?g/kg浓度水平,回收率均在90.5%~100.2%之间,相对标准偏差为1.4%~3.2%。结论改进后的方法回收率高、准确性高,对牛乳中双甲脒残留物的检测具有重要意义。     

A simple and quick gas chromatographic method for the determination of propham and chlorpropham in potatoes.

This study describes a gas chromatographic method for the quantitative determination of residual propham and chlorpropham in potatoes. Both herbicides are extracted from the foodstuff with methylene chloride. After centrifugation and concentration, propham and chlorpropham are quantitatively determined by gas chromatography thermionic detection using a fused silica capillary column CP Sil 5CB. 2-Chloraniline is used as internal standard. Recoveries of 100 +/- 15% and 99 +/- 10% have been obtained for propham and chlorpropham in blank samples spiked at the level of 0.5, 1.0 and 5.0 mg/kg. The absolute detection limit for both compounds is 1 ng corresponding to 0.1 mg/kg. Of the 161 samples of fresh potatoes analysed using this method, 136 contained residues of these herbicides and 18 of them (11%) exceeded the maximum tolerated value of 5 mg/kg.     

Residues in Young Veal Calves After Consumption of Milk Containing Penicillin

Residues in urine, kidney, and muscle following consumption of milk containing procaine penicillin G were determined in 4-to 8-day-old Holstein bull calves. Calves were fed milk diluted 1:1 with water. Nine control calves received diluted milk only while 8 calves received diluted milk containing 6,600 IU penicillin/kg (low group), and 10 calves received 13,200 lU/kg of milk consumed (high group). Urine samples were collected over 11 h after each morning feeding for 3 days. Calves were slaughtered on day 4 of trial and kidney, muscle, and urine samples obtained. Urine was tested for residues with the Live Animal Swab Test and tissues by the Swab Test on Premises. Both tests are microbiological assays used for detecting growth inhibition of Bacillus subtilis. No residues were detected in urine of control calves. Residues in urine were detected in 6 calves in the low group and 7 calves in the high group after feeding. At slaughter, residues were in 3 of 5 urine samples from calves in the low group and 8 of 10 calves in the high group. However, no residues were detected in kidney or muscle of control or treated calves.     

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.     

Multimethod for the determination of residues of chemotherapeutic drugs, antiparasitic agents and growth promotors in foodstuffs of animal origin. 1. General procedure and determination of sulfonamides

Applying this Multi-Method, it is possible to isolate more than 60 chemotherapeutics, antiparasitics and growth promoters in one procedure from eggs, milk and meat. Residues are detected by different chromatographic systems (HPLC with UV-Detection, Capillary-GC with an ECD). Depending on substance and foodstuff, the following detection limits can be achieved: (Table: see text). The observance of the legal tolerance level of 0.001 mg/kg Chloramphenicol (valid only for milk and eggs in the Fed. Rep. Germany) can be supervised. Residues of most Sulfonamides can be determined to adequately, check the proposed tolerance level of 0.1 mg/kg. The first part presents the procedure (applicable for all substances) and contains the summary of the chromatographic parameters for the detection of all substances and the detailed parameters for Sulfonamides. The conformation of residues of Sulfonamides is discussed carefully.     

Determination of 4-hydroxycoumarin rodenticides in animal products, fishery products, and honey by liquid chromatography-tandem mass spectrometry

A sensitive and selective method for the determination of 4-hydroxycoumarin-type rodenticides (warfarin, coumatetralyl, bromadiolone, and brodifacoum) in animal products, fishery products, and honey was developed. 4-Hydroxycoumarin rodenticides were extracted with acidified acetone, and the crude extract was purified by liquid-liquid partitioning followed by PSA column cleanup. Gradient liquid chromatographic separation was performed by using an Inertsil ODS-4 column, with methanol and water containing ammonium acetate as the mobile phase. Detection was carried out on a tandem mass spectrometer with electrospray ionization in the negative mode. Average recoveries from bovine muscle, bovine liver, bovine fat, swine muscle, salmon, eel, freshwater clam, egg, milk, and honey spiked at 0.0005-0.001 mg/kg were in the range of 79-108%, and the relative standard deviations were 2-8%. The limits of quantitations of the developed method were 0.0005 mg/kg for brodifacoum, 0.001 mg/kg for warfarin, coumatetralyl, and bromadiolone.     

高效液相色谱法测定动物源性食品中角黄素、虾青素的研究

研究并建立了高效液相色谱测定动物源性食品中角黄素、虾青素的方法。采用加有抗氧剂BHT的乙腈提取、正己烷脱脂制备样液。黄鱼、鳗鱼、鸡肉、鸡蛋、鸭肝、猪肾、牛奶等样品添加0.1～1 mg/kg的角黄素和虾青素时,角黄素和虾青素平均回收率范围分别为84.2%～103.1%和83.1%～98.7%,RSD范围分别为3.0%～10.5%和2.0%～8.9%,测定低限0.1 mg/kg。