Assessing the depletion of lincomycin in feathers from treated broiler chickens: a comparison with the concentration of its residues in edible tissues

ABSTRACT

Lincomycin is the first antimicrobial agent described for the lincosamide class and it is commonly used for the treatment of infectious enteric and respiratory diseases in poultry. Maximum residue limits (MRLs) in edible tissues have been established for this antimicrobial, however, no regulation has been proposed yet for by-products that are not intended for direct human consumption. Feathers are a by-product from poultry farming that might be used as an ingredient for diets fed to other farm animal species. The presence of antimicrobial residues in them is not monitored in spite of the fact that several studies have proved that they can persist in feathers. Currently though, no evidence has been presented regarding the behaviour of lincomycin in this matrix. Hence, this work intended to assess the depletion of lincomycin residues in feathers of birds treated with therapeutic doses and compare them with those detected in muscle and liver samples. Samples were collected for several days after ceasing treatment from a group of broiler chickens treated with a 25% lincomycin formulation. Methanol and Florisil® columns were used to extract and retain the analyte, and samples were analysed using a triple quadrupole mass spectrometer (API 5500, AB SCIEX?). On day 1 after ceasing treatment, average concentrations of lincomycin detected in feather samples reached up to 8582 μg kg^?1 and by day 16, these had only declined by 63%, to an average of 3138 μg kg^?1. Lincomycin residues were detected in feathers at every sampling point, even after they were not detectable in edible tissues. Depletion time was 98 days for feathers, considering the LOQ established for the methodology as cut-off value for the calculations. Data showed that lincomycin is highly persistent in feathers, which may result in this matrix becoming a re-entry route for its residues into the food chain.     

HPLC-MS/MS法检测鸡肉食品中金刚烷胺残留

采用HPLC-MS/MS法对鸡肉食品中金刚烷胺的残留进行了检测分析.结果显示,在103份待测样品中19份检测到金刚烷胺残留,其在鸡肝、鸡翅、鸡腿中的残留量分别为5.5、32.6～92.4、11.4～25.3μg/kg,而在鸡胸肉中未有检出.上述结果表明,鸡体的不同部位所含金刚烷胺的残留量不尽相同,同时也表明,在鸡养殖行业内还部分地存在金刚烷胺的违规使用现象,有必要对该违规行为作进一步的监管.     

Rapid multi-class multi-residue method for the confirmation of chloramphenicol and eleven nitroimidazoles in milk and honey by liquid chromatography-tandem mass spectrometry (LC-MS)

A confirmatory method was developed to allow for the analysis of eleven nitroimidazoles and also chloramphenicol in milk and honey samples. These compounds are classified as A6 compounds in Annex IV of Council Regulation 2377/90 (European Commission 1990) and therefore prohibited for use in animal husbandry. Milk samples were extracted by acetonitrile with the addition of NaCl; honey samples were first dissolved in water before a similar extraction. Honey extracts underwent a hexane wash to remove impurities. Both milk and honey extracts were evaporated to dryness and reconstituted in initial mobile phase. These were then injected onto a liquid chromatography-tandem mass spectrometry (LC-MS/MS) system and analysed in less than 9 min. The MS/MS was operated in multiple reaction monitoring (MRM) mode with positive and negative electrospray ionization. The method was validated in accordance with Commission Decision 2002/657/EC and is capable of analysing metronidazole, dimetridazole, ronidazole, ipronidazole and there hydroxy metabolites hydroxymetronidazole, 2-hydroxymethyl-1-methyl-5-nitroimidazole, and hydroxyipronidazole. The method can also analyse for carnidazole, ornidazole, ternidazole, tinidazole, and chloramphenicol. A recommended level of 3 µg l^?1/µg kg^?1 for methods for metronidazole, dimetridazole, and ronidazole has been recommended by the Community Reference Laboratory (CRL) responsible for this substance group, and this method can easily detect all nitroimidazoles at this level. A minimum required performance level of 0.3 µg l^?1/µg kg^?1 is in place for chloramphenicol which the method can also easily detect. For nitroimidazoles, the decision limits (CCα) and detection capabilities (CCβ) ranged from 0.41 to 1.55 µg l^?1 and from 0.70 to 2.64 µg l^?1, respectively, in milk; and from 0.38 to 1.16 µg kg^?1 and from 0.66 to 1.98 µg kg^?1, respectively, in honey. For chloramphenicol, the values are 0.07 and 0.11 µg l^?1 in milk and 0.08 and 0.13 µg kg^?1 in honey. Validation criteria of accuracy, precision, repeatability, and reproducibility along with measurement uncertainty were calculated for all analytes in both matrices.     

A preliminary study of presence of resveratrol in skins and pulps of European and Japanese plum cultivars

BACKGROUND: Resveratrol is a polyphenol with health properties being mainly present in the skins of several foods. However, any study has been carried out to analyze the presence of this stilbene in the plum fruit from the genus Prunus in European and Japanese cultivars. RESULTS: The analysis of resveratrol from the skin in different cultivars of plums from Spanish markets with liquid chromatography coupled to ultraviolet (LC‐UV) detector with subsequent confirmation by LC‐MS/MS has been demonstrated that contents of this compound in plums ranged from 0.1 to 6.2 µg/g. CONCLUSIONS: Values of resveratrol in European plum cultivars is higher than in Japanese cultivars. Copyright © 2012 Society of Chemical Industry     

Purification and identification of kokumi-enhancing peptides from chicken protein hydrolysate

The Maillard reaction products (MRPs) from chicken protein hydrolysate were demonstrated to have intense umami and kokumi-enhancing effects. To find the main flavour-enhancing compounds in the chicken protein hydrolysate, the fractions with different molecular weights were obtained by ultrafitration. The evaluation of taste characteristics revealed that the fractions with molecular weights ranging from 1000 to 5000 Da predominantly contributed to the umami and kokumi-enhancing effects. After further purification by using ultrafiltration, gel filtration chromatography, and ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) in combination with sensory evaluation, three peptides were identified, an octapeptide (WVNEEDHL), a nonapeptide (NSLEGEFKG) and a decapeptide (KDLFDPVIQD). Sensory evaluation results showed that all three peptides could significantly enhance the meat flavour, umami taste and thickness of the chicken powder solution. The results indicate that the peptides have potential application as effective chicken flavour-enhancing ingredients in the food industry.     

高效液相色谱-质谱联用测定乳制品中6种四环素类抗生素

建立了乳制品中6种四环素类抗生素残留的高效液相色谱-电喷雾离子阱质谱联用测定方法。该方法采用多反应监测正离子模式，可一次对6种四环素类抗生素进行定性和定量分析。该方法的检出限0．5-4．0μg/L，测定低限牛奶0．6-4.5μ/L，乳粉为6．0-45．0μg/kg，线性范围4．0-100．0μg／L，加标回收率56．1％-104．9％，相对标准偏差为2．5％-15．0％。该法具有样品预处理简单，灵敏度高，分析时间短等优点。     

Deposition and depletion of maduramicin residues in eggs after oral administration to laying hens determined by LC-MS

The coccidiostat maduramicin has been approved as a feed additive for chickens and turkeys, although it is prohibited for use in laying hens. In the present study, laying hens were divided into three groups and fed for 14 days with medicated feed containing maduramicin, at three different concentrations: 50, 100 and 500 µg kg^?1. Eggs were collected during treatment and for 26 days after the end of feeding with medicated feed. Maduramicin residues were found exclusively in egg yolk, with the highest concentration in egg yolk of 459 µg kg^?1 for the highest dose. The maximum concentration of maduramicin in whole egg was 16.6 µg kg^?1 for the group receiving feed containing the maximum permitted level of maduramicin in feed (50 µg kg^?1). The half-life of elimination of maduramicin, calculated for post-treatment days 1–10, was 6.5 days. Twelve days after drug administration, the concentration of the maduramicin in egg yolk for Group 3 (fed with 500 µg kg^?1 maduramicin) still exceeded 20 µg kg^?1, while the concentrations for Groups 1 and 2 were 1.2 and 2.7 µg kg^?1, respectively.     

Measurement of ampicillin residue levels in chicken eggs during and after medicated feed administration by LC-MS/MS

A simple and sensitive LC-MS/MS method was developed and validated for the determination of ampicillin (ABPC) in chicken eggs. Residues were extracted by reverse-phase solid-phase extraction. Chromatographic separation was performed using a reverse-phase column with an elution gradient. The limits of detection and quantification were 0.01 and 0.1 ng g^?1, respectively. For the 0.1–50 ng g^?1 concentration range, mean recovery and accuracy values were 93.9–98.5% and 100.2–118.0%, respectively. ABPC residue concentrations in eggs before, during and after 7 days of medicated feeding of maximum dosage (40 mg kg^?1 body weight day^?1) of ABPC were determined with the LC-MS/MS method. The maximum concentration of ABPC in eggs was 3.6 ± 1.7 ng g^?1 (mean ± SD) on the last day of the administration period. Residue concentrations of ABPC in eggs during and after ABPC administration were not over the Japanese maximum residue limit of 0.01 mg kg^?1.     

A novel approach to simultaneous screening and confirmation of regulated pharmaceutical compounds in dietary supplements by LC/MS/MS with an information-dependent acquisition method

The commercial success of synthetic phosphodiesterase-5 (PDE-5) inhibitors (viz. sildenafil, vardenafil and tadalafil) for erectile dysfunction (ED) has led to their widespread use as adulterants in dietary supplements (DSs). Reports on adulteration by ED drugs or their analogues in DSs suggest they may cause a serious threat to human health. The problem is becoming more complex as hidden and structurally modified analogues are continuously being reported. To analyse known drugs and their analogues, three commonly used PDE-5 inhibitors, naturally existing icariin and yohimbin, and their 19 analogues were analyzed in this study. They were identified using ion-spray liquid chromatography/tandem mass spectrometry (LC/MS/MS) using multiple reaction monitoring (MRM). This MRM procedure gave a limit of detection of less than 0.02?ng?ml^?1 for the 24 compounds, selectivity of fragmentation using MRM for 2.5?–?8.5?min in a single run and peak height repeatability of coefficient of variation of 3.9?–?31.8%. An IDA method using the MRM scans to detect the presence of known analytes was set up and added to a built-in library for screening for PDE-5 inhibitors. These MRM experiments were used to trigger product ion scans using a hybrid quadrupole-linear ion trap instrument. The product ion scan was compared and confirmed by a library search of MS/MS spectra acquired from a reference standard. To search for new analogues of PDE-5 inhibitors, a precursor ion scan of an expected ion m/z 283, which was one of the mass fragments from the analogues of sildenafil or vardenafil, was performed and fragmentation of the precursor ion, by combining a precursor ion scan with automatic confirmation using EPI spectra, was acquired. Of the 37 DSs tested, two were eventually found to be adulterated with yohimbin and vardenafil, respectively. The approach proposed in this study would be valuable in characterizing chemical constituents of drug residues and their analogues with identical chemical substructures from complex natural and synthetic sources in DSs using an information-dependent acquisition-enhanced product ion (IDA–EPI) scan.     

Pyrrolizidine alkaloids in honey: comparison of analytical methods

Pyrrolizidine alkaloids (PAs) are a structurally diverse group of toxicologically relevant secondary plant metabolites. Currently, two analytical methods are used to determine PA content in honey. To achieve reasonably high sensitivity and selectivity, mass spectrometry detection is demanded. One method is an HPLC-ESI-MS-MS approach, the other a sum parameter method utilising HRGC-EI-MS operated in the selected ion monitoring mode (SIM). To date, no fully validated or standardised method exists to measure the PA content in honey. To establish an LC-MS method, several hundred standard pollen analysis results of raw honey were analysed. Possible PA plants were identified and typical commercially available marker PA-N-oxides (PANOs). Three distinct honey sets were analysed with both methods. Set A consisted of pure Echium honey (61–80% Echium pollen). Echium is an attractive bee plant. It is quite common in all temperate zones worldwide and is one of the major reasons for PA contamination in honey. Although only echimidine/echimidine-N-oxide were available as reference for the LC-MS target approach, the results for both analytical techniques matched very well (n?=?8; PA content ranging from 311 to 520?µg?kg^?1). The second batch (B) consisted of a set of randomly picked raw honeys, mostly originating from Eupatorium spp. (0–15%), another common PA plant, usually characterised by the occurrence of lycopsamine-type PA. Again, the results showed good consistency in terms of PA-positive samples and quantification results (n?=?8; ranging from 0 to 625?µg?kg^?1 retronecine equivalents). The last set (C) was obtained by consciously placing beehives in areas with a high abundance of Jacobaea vulgaris (ragwort) from the Veluwe region (the Netherlands). J. vulgaris increasingly invades countrysides in Central Europe, especially areas with reduced farming or sites with natural restorations. Honey from two seasons (2007 and 2008) was sampled. While only trace amounts of ragwort pollen were detected (0–6.3%), in some cases extremely high PA values were detected (n?=?31; ranging from 0 to 13019?µg?kg^?1, average?=?1261 or 76?µg?kg^?1 for GC-MS and LC-MS, respectively). Here the results showed significantly different quantification results. The GC-MS sum parameter showed in average higher values (on average differing by a factor 17). The main reason for the discrepancy is most likely the incomplete coverage of the J. vulgaris PA pattern. Major J. vulgaris PAs like jacobine-type PAs or erucifoline/acetylerucifoline were not available as reference compounds for the LC-MS target approach. Based on the direct comparison, both methods are considered from various perspectives and the respective individual strengths and weaknesses for each method are presented in detail.     

超高效液相色谱串联质谱法快速检测鸡蛋和鸡肉中的非泼罗尼及其代谢物的残留量

目的建立超高效液相色谱串联质谱法(ultra performance liquid chromatography tandem mass spectrometry,UPLC-MS/MS)检测鸡蛋和鸡肉中非泼罗尼及其代谢物(氟甲腈、非泼罗尼硫醚和非泼罗尼砜)残留量的分析方法。方法鸡蛋和鸡肉中的非泼罗尼及其代谢物经乙腈提取后,加入盐析剂进行分层,经Oasis PRi ME HLB固相萃取净化后,UPLC-MS/MS法检测,基质匹配标准曲线法定量。结果该方法具有良好的准确度和精密度,在鸡蛋和鸡肉中添加回收率范围分别为79.2%~103.1%和83.5%~101.4%,相对标准偏差(relative standard deviation,RSD)低于8.1%。方法的检出限和最低定量限分别为0.5μg/kg和1.0μg/kg。结论该方法具有分析时间短、样品处理简单、溶剂用量少等优点,适用于鸡蛋和鸡肉中非泼罗尼及其代谢物残留量的常规检测。     

An intercomparison study of the determination of glyphosate, chlormequat and mepiquat residues in wheat

An intercomparison study of the determinations of glyphosate, chlormequat and mepiquat residues in cereals was performed. Four samples comprising one blank, two incurred and one spiked sample were sent to six participating laboratories. For glyphosate, two laboratories reported considerably lower results than the other four. One of the two laboratories with low results also reported low recoveries. The results of a sample spiked with 0.80 mg kg^-1 glyphosate and an incurred sample, ranged from 0.23-0.87 mg kg^-1 and 0.11-0.25 mg kg^-1 respectively. The strong correlation between the two samples (r² = 0.95) indicates a systematic between-laboratory variation. Several different principles were used for the analysis of glyphosate using different clean-up techniques and GC/MS, HPLC-fluorescence or LC/MS for detection. The results of the chlormequat residues showed more consistency. All but one laboratory obtained comparable results. However the correlation between the results for the sample spiked with 0.38 mg kg^-1 (range: 0.26-0.65 mg kg^-1) and the incurred samples (range: 0.19-0.45 and 0.15-0.23 mg kg^-1, respectively) again showed a strong correlation (r² = 0.99 and 0.88) indicating a systematic component. For mepiquat, results above the limit of quantification were only reported for the spiked sample. The results ranged from 0.29-0.92 mg kg^-1 (spiked concentration = 0.38 mg kg^-1). Three laboratories had results that deviated less than 25% from the fortified concentration. Two laboratories reported results 38% and 141% above the fortified concentration, respectively.     

选择离子流动管质谱法测定油脂中的呋喃

目的测定食用油等油中的呋喃含量。方法将5 g油样密封于(540±5)mL瓶中,加入一定量呋喃(X),于65℃水浴加热1 h后测定其呋喃(Y)含量。选择离子流动管质谱(selected ion flow tube mass spectrometry,SIFT/MS)方法,以NO+为初始离子,测定油样密封瓶顶空中呋喃浓度,再据呋喃标准曲线定量密封瓶中油样的呋喃含量。结果所得标准曲线为:Y=29.55X+1.11(r~2=0.9867,n=6),其检测限和定量限分别为0.052 ng/g和0.063 ng/g。利用该标准曲线测定多种油,其中废弃餐用油(即各种类型的地沟油、煎炸老油等)呋喃含量为4.37~17.83 ng/g;大豆油、花生油、两种菜籽油、茶油、葵花油的呋喃含量均小于1 ng/g;两种冷榨橄榄油的呋喃含量分别为1.19和4.39 ng/g。结论该法可方便、快速、准确地测定油样中呋喃的含量,呋喃可以作为鉴伪食用油和废弃餐用油的特征性指标。     

食品中呋虫胺残留量的HPLC-MS/MS检测方法研究

用液相色谱-质谱/质谱法测定食品中呋虫胺残留量。样品用乙腈提取,提取液加入无水硫酸钠脱水后,用石墨化非多孔碳柱(Envi-Carb)/酰胺丙基甲硅烷基化硅胶柱(LC-NH2)净化,液相色谱-质谱/质谱法测定,外标法定量。测定方法在测量范围内具有良好的线性关系(r>0.999),测定的回收率范围为67%～90%,检出限为10μg/kg,相对标准偏差为3.15%～8.36%。     

高效液相色谱-电喷雾电离串联质谱法测定鸡肉、鸡蛋中氯霉素、甲砜霉素和氟苯尼考药物残留量

目的建立高效液相色谱-电喷雾电离串联质谱法测定鸡肉和鸡蛋中氯霉素、甲砜霉素、氟苯尼考残留量的分析方法。方法准确称取5 g样品,添加同位素内标氯霉素-d5后,乙腈提取,LC-Si硅胶小柱净化,正己烷进一步除脂,0.22μm滤膜过滤后高效液相色谱-电喷雾电离串联质谱测定。采用负离子电喷雾电离源,多反应监测(multiple reaction monitoring,MRM)模式。结果氯霉素、甲砜霉素和氟苯尼考在0.5~200μg/L的系列浓度范围内线性良好,其线性方程分别为Y=0.880X-0.215,Y=0.032X-0.076和Y=0.108X-0.115,相关系数r~2均大于0.990;方法的检测限和定量限分别是0.05μg/kg和0.1μg/kg;在加标水平在0.1~5.0μg/kg的范围内,鸡肉基质中平均回收率在87.01%~117.8%之间,鸡蛋基质中平均回收率在80.74%~115.0%之间;方法的日内精密度相对标准偏差在4.02%~9.88%之间,日间精密度相对标准偏差在5.72%~12.78%之间。结论该方法简单易行,回收率好,灵敏度高,特异性好,能满足目前大多数日常检测和监督的需要。     

Influence of food condiments on the formation of carcinogenic heterocyclic amines in cooked chicken and determination by LC-MS/MS

Heterocyclic amines (HCAs) are known to be suspected human carcinogens produced by high-temperature cooking of protein-rich foods such as meat and fish. In the present study, the influence of numerous food condiments on the formation of HCAs in cooked chicken was investigated. Chicken samples were subjected to pan-frying under controlled temperature. The levels of HCAs DMIP, MeIQx, 4,8-DiMeIQx, PhIP, harman and norharman were found to be between 0.93 and 27.52 ng g^?1, whereas IQ, MeIQ, AαC, MeAαC, Trp-P-1 and Trp-P-2 were found either below the limit of quantification or not detected in the control sample. Nevertheless, for samples cooked using food condiments, the amounts of HCAs (DMIP, MeIQx, 4,8-DiMeIQx and PhIP) were between 0.14 and 19.57 ng g^?1; harman and norharman were detected at higher concentrations up to 17.77 ng g^?1 while IQ and MeIQ were at levels below the limit of quantification; and AαC, MeAαC, Trp-P-1 and Trp-P-2 were not detected in any of the samples. The outcomes revealed that the formation of HCAs (except harman and norharman) diminished after the addition of food condiments. Edible oil contributed to the highest levels of HCA formation, followed by garlic, paprika, pepper and tomato.     

全自动固相萃取-超高效液相色谱-串联质谱法测定鸡肉中的金刚烷胺和利巴韦林

目的建立全自动固相萃取-超高效液相色谱-串联质谱法(ultra performance liquid chromatographytandem mass spectrometry,UPLC-MS/MS)同时测定鸡肉中金刚烷胺和利巴韦林含量的分析方法。方法样品加入同位素内标后用三氯乙酸和乙酸铵缓冲液提取,经PBA/PCX复合固相萃取柱净化后,用Acquity UPLC~HSS T3柱(3.0 mm×150 mm,1.8μm)分离,以乙腈和0.2%甲酸作为流动相进行梯度洗脱,电喷雾正离子模式(ESI+)电离,多反应监测模式(multiple reaction monitoring,MRM)进行检测。结果金刚烷胺在0.2~10 ng/mL范围内线性关系良好,方法的检出限为(S/N=3)0.02μg/kg,在0.6、2.4和12μg/kg添加水平的平均回收率分别为92.2%、99.2%和99.2%,相对标准偏差(n=6)为6.2%、4.3%和1.5%。利巴韦林在1.0~50 ng/mL范围内线性关系良好,方法的检出限为(S/N=3)0.1μg/kg,在3.0、12和60μg/kg添加水平的平均回收率分别为99.0%、97.5%和97.2%,相对标准偏差(n=6)为4.9%、2.8%和1.4%。结论该方法简单、灵敏、准确可靠,适用于鸡肉中金刚烷胺和利巴韦林含量的同时测定。     

SPE-LC/MS/MS法同时测定烟叶中5种新烟碱类杀虫剂残留

通过比较硅胶柱、石墨化碳柱、C18柱和聚合物柱对分析物的保留能力,建立了20％甲醇水溶液超声萃取、Pesticarb石墨化碳柱固相萃取、LC-MS/MS同时测定烟叶中5种新烟碱类杀虫剂“烯啶虫胺”、“噻虫嗪”、“吡虫啉”、“啶虫咪”和“噻虫啉”残留的方法.结果表明,方法的检测限为0.005～0.009 μg/mL,平均回收率为80％～92％,RSD为2.50％ ～ 4.08％.该方法适用于烟叶中这5种新烟碱类杀虫剂残留的快速检测.