Quantitative analysis of lincomycin and narasin in poultry, milk and eggs by liquid chromatography-tandem mass spectrometry

This study presents the simultaneous extraction and determination of lincomycin (LCM) and narasin (NAR) by using liquid chromatography-electrospray ionisation tandem mass spectrometry (LC-MS/MS) on samples from poultry, milk and eggs (n = 196). The homogenised samples are extracted with acetonitrile and the extract is further cleaned using C₁₈ solid-phase extraction cartridges. The recoveries of the analytes in different matrices were found ranging from 90% to 101% and 85% to 95% for LCM and NAR, respectively. The corresponding limits of detection were 0.6 and 1.5 ng g⁻¹ for LCM and NAR, respectively. As a result of monitoring, NAR was not detected in any samples and LCM was detected in one egg with a concentration of 25 ng g⁻¹. The method was relatively simple to perform and therefore could be used for food safety surveillance activities.     

鸡蛋烘烤工艺技术条件研究

对鸡蛋烘烤工艺条件进行了一系列研究。确定采用配方Ⅳ浸泡、煮制时间7min、烘烤温度80℃、烘烤时间22h，成品呈琥珀色、光亮，有浓郁的烤、卤蛋混合香味。开发出了一种新型的鸡蛋制品。     

Sulphonamide residues in eggs following drug administration via the drinking water

The aim was to determine concentrations of sulphadimidine (SDM) and sulphadimethoxine (SDT) in eggs following oral administration through drinking water for 5 days (0.5g^-1 for SDT, 1 and 2gl^-1 for SDM). Residues of sulphonamides in albumen and yolk were monitored by high-performance liquid chromatography with UV detection. The limit of quantification was 0.005 μg g^-1 for the two egg components. The results indicate that 0.9-1.4% of the dose administered was deposited in eggs. Maximum concentrations in albumen were much higher than those in yolk. More than 75% of the overall sulphonamides detected in eggs was concentrated in the albumen. The residue levels declined below the limit of quantification within 12-20 days for albumen and 14-15 days for yolk after treatment was discontinued.     

Determination of ochratoxin A in eggs and target tissues of experimentally drugged hens using HPLC–FLD

Ochratoxins are fungal secondary metabolites that may contaminate various foods and beverages. The intake of ochratoxins by humans may result in typical syndromes (nefrotoxicity, carcinogenity, teratogenicity and immunotoxicity) and has been associated with Balkan Endemic Nephropathy (BEN). In this study we evaluated the effects of accumulation of ochratoxin A throughout the chain production of eggs, by investigating the dynamics of OA accumulation in eggs placed by laying hens experimentally exposed to OA.     

皮蛋国家卫生标准制修订研究

为修订ＧＢ５１２８—８５皮蛋卫生标准,对标准执行情况进行了研究,收集统计分析了１４省７７５份皮蛋卫生指标检测数据。根据皮蛋加工工艺的改进对皮蛋进行了分类,对铅等重金属指标进行了修订并增加了锌、铜等指标。建议皮蛋卫生指标：传统工艺生产的皮蛋铅≤２ｍｇ／ｋｇ,砷≤０．５ｍｇ／ｋｇ,ｐＨ≥９．５;非传统工艺生产的皮蛋铅≤０．５ｍｇ／ｋｇ,砷≤０．５ｍｇ／ｋｇ,铜≤１０ｍｇ／ｋｇ,锌≤２０ｍｇ／ｋｇ;硬心皮蛋及其它皮蛋铅≤０．５ｍｇ／ｋｇ,砷≤０．５ｍｇ／ｋｇ,ｐＨ≥９．５,菌落总数≤５００／ｇ;大肠菌群≤３０ＭＰＮ／１００ｇ,致病菌不得检出     

Authentication of organic and conventional eggs by carotenoid profiling

Organic production benefits from fair competition and sustained consumer confidence. The latter can only be assured by paper trailing and verification assessments. Traditional analytical strategies for guaranteeing quality and uncovering adulteration have relied on the determination of the amount of a marker compound or compounds in a material and a subsequent comparison of the value(s) obtained with those established for equivalent material. Since it is unlikely to find a unique marker that allows discrimination between organic and conventional produce, selective fingerprinting (profiling) combined with chemometrics is a more promising approach. In this study, carotenoid High Performance Liquid Chromatography–Diode Array Detection profiling combined with k-nearest neighbour classification chemometrics was used to predict the production system (organic vs. non-organic) of chicken eggs. A proof-of-concept set (training set for the model) was composed of eggs from 24 organic farms, 12 free range, and 12 barn farms in the Netherlands. The identities of organic, free range, and barn eggs were predicted with success rates of 100%, 100%, and 84%, respectively. The identity of eggs determined using an additional market test set with eggs from 12 organic, 12 free range, and 12 barn farms originating from the Netherlands and New Zealand resulted in correct classifications for 35 of the 36 samples. The results of this study indicate that this fingerprint approach is a promising tool for analytical verification of the production system of organic eggs.     

高效液相色谱法测定鸡蛋中角黄素的不确定度评定

目的 评定高效液相色谱法测定鸡蛋中角黄素含量的不确定度.方法 样品经乙腈水浴超声提取和离心,取上清液用正己烷脱脂,再用旋转蒸发仪浓缩后,乙腈定容,经C18色谱柱分离,流动相等度洗脱,采用高效液相色谱仪(紫外-可见检测器)在波长471 nm进行测定.外标法定量测定鸡蛋中角黄素含量.依据JJF 1135—2005《化学分析...     

Nicarbazin contamination in feeds as a cause of residues in eggs

A survey was carried out to investigate the prevalence of nicarbazin residues in eggs in Northern Ireland. Nicarbazin, in the form of 4,4-dinitrocarbanilide (DNC), was detected in 39 of the 190 eggs analysed. An experiment was designed to establish the relationship between nicarbazin-contaminated feed and nicarbazin residues in eggs. The concentrations of both the DNC and 4,6-dimethyl-2-hydroxypyrimidine (DHP) components of the drug in eggs were proportional to feed levels. The maximum feed nicarbazin concentration of 12.1mg/kg (8.6 mg/kg DNC and 3.5mg/kg DHP) gave rise to mean maximum whole egg concentrations of 631 mu g/kg DNC and 51.8 mu g/kg DHP. After withdrawal of the experimental diet, DNC was undetectable in eggs after 12 days and DHP after 3 days. Feed contaminated with nicarbazin at concentrations greater than about 2mg/kg gave rise to egg DNC residues at concentrations greater than the Differential Action L imit (DAL) set by the UK (100 mu g/kg). DNC was contained almost entirely in the yolk of the egg, whereas DHP was distributed between albumen and yolk in a ratio of approximately 3:1.     

鸡蛋酸乳的工艺及风味的研究

以新鲜鸡蛋、酸奶为主要原料,配以白砂糖、稳定剂等辅料,运用合理的加工工艺,通过正交试验和感官评定的方法,研制出了一种风味独特、多种营养素兼容的具有保健功能的搅拌型酸奶,研究结果表明鸡蛋酸乳的最佳发酵条件为:蛋液代替度(40%,V/V),蛋稀释倍数为5,增稠剂添加量为0.2%、加糖量7%,接种量3%。对产品也进行了相应的各项理化性质、微生物指标的检验和感官进行评定,均符合标准。     

2009年禽蛋市场价格回顾及展望

2009年是极不寻常的一年,国际金融危机蔓延对世界经济产生了重大影响。回顾2009年,国内鸡蛋零售价格一波三折,总体是震荡上升的。引起鸡蛋价格波动的原因来自多方面,主要包括饲料成本不断上涨、蛋鸡存栏出现短期变化、季节效应和节日效应明显、突发事件引发短暂剧烈波动等。国际市场方面,美国鸡蛋批发价格上半年受金融危机影响甚大,下半年随着经济形势好转价格回升明显,全年呈现"V"型反弹;加拿大鸡蛋批发价格较为平稳;国际期货市场价格年底大幅跳水。     

Development and validation of a liquid chromatographic-tandem mass spectrometric method for determination of eleven coccidiostats in milk

A reversed phase liquid chromatographic–tandem mass spectrometric method with simple solvent extraction and purification by solid phase extraction (SPE) has been developed for the determination of coccidiostats in milk. For sample preparation matrix solid phase dispersion, extraction by organic solvent and SPE with different cartridges were also tested. The compounds determined include lasalocid, narasin, salinomycin, monensin, semduramicin, maduramicin, robenidine, decoquinate, halofuginone, nicarbazin and diclazuril. Main steps of the method are addition of acetonitrile to the milk samples, centrifugation, removal of matrix by SPE, concentration by evaporation and LC–MS–MS determination. During a 15 min time segmented chromatographic run compounds are ionised either positively or negatively. Calculated recoveries range between 77.1% and 118.2%. Maximum levels are in the range of 1–20 μg/kg. The developed method was validated in line with the requirements of Commission Decision 2002/657/EC (2002). It is applicable for control of coccidiostat residues in milk as indicated in Regulation 124/2009/EC (2009).     

2022年我国鸡蛋中4种抗球虫药物残留状况及暴露评估

目的 初步了解我国鸡蛋中抗球虫药物的残留情况,评估其膳食暴露风险。方法 对2022年我国31个省（自治区、直辖市）采集的1 968份鸡蛋样本中4种抗球虫药物的残留数据进行统计分析,采用点评估方法分别评估儿童和成人通过摄入鸡蛋而暴露于抗球虫药物的膳食风险。结果 4种抗球虫药物有不同程度的检出,总体检出率为3.40%。在不同的采样环节中,检出率依次为农贸市场最高,其次是网店,最后是商店。散装食品的检出率高于定型包装食品。检出率排名前6的依次为海南、内蒙古、江西、湖北、云南和四川。根据4种兽药残留的平均值得到各年龄段的膳食暴露量范围为1.97×10^-4~3.92×10^-3 μg/（kg·BW/d）。托曲珠利砜是各年龄段中贡献率最高的抗球虫药物。3种抗球虫药物膳食暴露的风险商均远低于1。结论 2022年我国30个省（自治区、直辖市）鸡蛋中抗球虫药物残留的总体检出率较低,但部分地区存在超标情况,需引起关注。通过鸡蛋摄入抗球虫药物的膳食暴露风险极低,但仍需加强监管和溯源工作,以进一步保障儿童的健康。     

Evaluation of the residues of furazolidone and its metabolite, 3-amino-2-oxazolidinone (AOZ), in eggs

The use of furazolidone in food-producing animals is banned within the EU. Detection of the protein-bound side-chain metabolite, 3-amino-2-oxazolidinone (AOZ), in animal tissues is the most effective method of enforcing the ban. The study was undertaken to find out if the same applies to eggs. The concentrations of furazolidone and AOZ in eggs reached a plateau of ~360-380 μgkg -1 by the fourth day of treating birds with 400mgkg -1 furazolidone. After a 4-day withdrawal from treatment, intact furazolidone could not be detected. AOZ residues could still be detected up to 21 days following withdrawal from treatment. During treatment, most intact furazolidone residues occur in the albumen. For AOZ, there is a more even distribution of residues between albumen and the yolk. The concentration of furazolidone in egg homogenates stored at -20°C decreases by 44% after 55 days. AOZ residues are stable during this period. From these results, it is clear that AOZ is a more suitable marker residue than the parent compound for monitoring concentrations of the drug in eggs.     

含茶多酚的壳聚糖涂膜对鸡蛋保鲜效果的影响

用茶多酚和壳聚糖制成的复合涂膜液对鸡蛋进行涂膜处理,以感官指标、失重率、蛋黄指数、蛋清pH值、哈夫单位为质量指标定期取样分析测定,研究所制成的涂膜液在室温条件下对鸡蛋的保鲜效果。结果表明,和对照相比,含茶多酚的壳聚糖涂膜液能较好地保持鸡蛋的新鲜度和品质,尤其以1.5%的壳聚糖溶液联合200mg/kg茶多酚制得的涂膜液保鲜效果最好,经此涂膜液处理后的鸡蛋室温下贮存35d,失重率为1.89%,蛋黄指数为0.26,哈夫单位为60.109,蛋清pH值为8.20。     

超高效液相色谱-串联质谱法同时检测鸡蛋中24种β-受体阻滞剂类药物

目的 建立一种超高效液相色谱-串联质谱法同时检测鸡蛋中24种β-阻滞剂类药物的方法。方法 使用80%乙腈水溶液提取目标物,QuEChERS法对提取液进行净化,乙腈饱和正己烷除脂,经Waters ACQUITY UPLC BEH C18(2.1×100 mm, 1.7 μm)色谱柱分离,以0.1%甲酸水溶液和乙腈作为流动相,进行梯度洗脱。采用电喷雾离子源正离子电离模式,使用多反应监测模式进行定量分析,外标法定量。结果 鸡蛋基质中24种β-受体阻滞剂在考察浓度范围内呈良好的线性关系(r≥0.9963),当称样量为1 g(精确至 0.001g),定容体积为2 mL时,方法检出限为3 μg/kg,定量限为10 μg/kg,平均加标回收率为63.63%~108.38%,相对标准偏差(RSD,n=6)为0.9%~7.4%。结论 本研究方法操作简单、回收率高、灵敏度高、重现性好,可为日常及体育赛事中鲜鸡蛋中β-受体阻滞剂残留分析提供技术参考。     

重庆市巴南区市售鸡蛋中残留兽药现状调查及膳食暴露风险评估

目的 了解重庆市巴南区市售鸡蛋中兽药残留现状,评估居民膳食摄入残留兽药导致的健康风险。方法 于2024年随机抽取重庆市巴南区10个镇街的集贸市场和超市售卖的鸡蛋共208份,采用液相色谱-串联质谱法(LC-MS/MS)检测15种兽药残留含量,通过点评估法计算每日估计暴露量和危害商,评估膳食暴露风险。结果 208份市售鸡蛋样本中兽药残留检出率8.65% (18/208),检出率最高为多西环素3.37% (7/208);不合格率0.96% (2/208),不合格样本主要来源于集贸市场售卖的散装无品牌鸡蛋。膳食暴露评估显示,兽药残留的每日估计暴露量范围为0.00013～0.03450μg/（kg·bw·d）,危害商范围为0.00000～0.00872,远低于安全阈值,提示摄入市售鸡蛋中残留兽药所引起的人体健康危害风险较低。结论 重庆市巴南区市售鸡蛋存在兽药残留现象,但残留量总体可控,健康风险较低。需重点关注散装和无品牌鸡蛋的监管,并完善兽药使用规范及残留限量标准。     

烟青虫／棉铃虫混合种群卵在烟田的空间分布特征研究──Ⅱ混合种群卵在麦茬烟和留种烟田的空间分布及其密度估测技术

研究表明，烟青虫／棉铃虫混合种群卵在麦茬烟田和留种烟田６～７月间均呈聚集分布。麦茬烟田，打顶前（６月）有５９．５２％的卵分布于蕾（尖）上，３５．５４％的卵分布于１～８片叶上；打顶后（８月）约有９５％的卵分布于１～８片叶上。留种烟田，６月、７月份分别有８８．７１％和９４．４４％的卵分布于蕾花上。两级抽样表明，田间调查６月份麦茬烟卵密度时（Ｄ＝０．０１），每块四查９０株，每株仅调查蕾（尖）至第６叶上的卵即可。