种猪常温精液畸形率不确定度评定

测量不确定度定义为表征合理地赋予被测定值的分散性，是判定测定结果质量的依据，一切测定结果都具有不确定度，测定结果的可用性很大程度取决于其不确定度的大小。本文根据GB23238—2009的要求，通过显微镜检测方法对种猪常温精液畸形率进行测定，对影响其测定结果的不确定度分量进行了评定，以确保种猪常温精液畸形率测定数据的可信度。     

硫酸蒽酮法测定柑橘渣中总糖的不确定度评定

<正>随着科学研究的不断深入,测量结果的准确性是影响科研成败的关键性因素之一[1]。测量不确定度是对测量结果质量和水平的科学表达,通过评定测量不确定度可以分析影响测量结果的主要成分,从而提高测定结果的质量。一切化学分析方法的测量结果都具有不确定度[2]。     

液相色谱-串联质谱法测定动物源食品中氯霉素残留量不确定度分析

1993年,ISO联系BIPM、IEC、IFCC、IUPAC、IUPAP和OIML出版了《测量不确定度表述指南》,正式确定了适用于广泛测量领域的评估和表达测量不确定度的通用原则,将不确定度评估引入实验室的质量保证措施中。不确定度是表征合理地赋予被测量之值的分散性,与测量结果相联系的参数。建立和实施各类检测的不确定度评定方法,既是提高检测质量的需要,也是实现检测数据国际互认所不可缺少的内容。本文根据《化学分析测量不确定度评定》对农业部781号公告-2—2006动物源食品中氯霉索残留量的测定高效液相色谱-串联质谱法的不确定度进行分析,探讨该方法的不确定度评定方法。     

HPLC法测定饲料中维生素B_2的不确定度评定

<正>测量的目的是为了确定被测量的量值,但由于测量的不完善和人们认知的不足,所得的量值具有分散性。通过分析和评定测量过程中产生的不确定度,得出一个可信区间,从而为评价检测结果的质量提供依据,尤其检测结果在临界值附近,难以判定是否合格时,不确定度显得尤为重要,因而测量不确定评定是检测和校准实验室必不可少的工作之一。     

猪活体背膘厚和眼肌面积不确定度评定

测量不确定度定义为表征合理地赋予被测定值的分散性,是判定测定结果质量的依据,一切测定结果都具有不确定度,测定结果的可用性很大程度取决于其不确定度的大小〔1〕。本文根据DB31T437-2009〔2〕的要求,通过B型超声波方法对猪活体背膘厚和眼肌面积进行了测定,对影响其测定结果的不确定度分量进行了评定,以确保B型超声波方法对猪活体背膘厚和眼肌面积测定数据的可信度。     

原子吸收光谱法测定饲料中镉测量不确定度的评定

测量不确定度是评定检测样品结果准确度的尺度,本文用原子吸收光谱法对饲料中镉的测量不确定度进行评定,依照JJF1059-1999《测量不确定度评定与表示》的要求,全面了解影响饲料中镉测定的不确定度。研究说明,评定中以A类评定分量占主要地位,评定不给自由度,包含因子统一取2的简化评定过程是可行的。     

耳标结合力测量的不确定度评定

为全面评价耳标结合力测量指标,分析耳标在结合力检测中的不确定度来源,对单次测量引起的不确定度分量进行不确定度评定,根据方差合成定理,合成标准不确定度,并计算扩展不确定度,给出结合力测量不确定度报告,完善耳标结合力单次测量结果的评定,为标准修订提供有效的参考值。     

牛乳菌落总数测定的不确定度评定

对牛乳样品菌落总数的测定结果进行不确定度评定,为检测过程的质量控制提供科学依据.依据GB 4789.2—2016《食品安全国家标准食品微生物学检验菌落总数测定》检测牛乳样品的菌落总数,按照JJF 1059.1—2012《测量不确定度评定与表示》分析该检测结果不确定度的来源并建立数学模型,然后分别对引入的不确定度分量进行...     

猪伪狂犬病毒gB抗体ELISA试验的测量不确定度评估

本试验目的 是对伪狂犬病毒gB抗体ELISA检测的不确定度进行评估,确保检测结果的准确性及可靠性.采用的方法是按照《兽医检测实验室ELISA试验测量不确定度评估指南CNAS-GL043-2020》来分析试验的不确定来源并评定各分量的标准不确定度、合成标准不确定度和扩展不确定度.评估结果显示,标准不确定度为0.055,扩...     

陶瓷砖破坏强度检测结果不确定度评定

任何一个理化检测结果,恒都只是被测量的一个估计值.如何保证检测结果的准确度,通过准确的定量分析来达到对产品定性的目的.文章主要对陶瓷砖破坏强度检测结果不确定度评定进行了探讨分析,可供同行技术交流.     

Soleris微生物快速检测系统在巴氏杀菌乳中的应用验证

[目的]为了验证Soleris微生物快速检测系统对巴氏杀菌乳中大肠菌群快速检测的时效性,以提高公司巴氏杀菌乳产品的出货时效。[方法]对Soleris微生物快速检测系统和传统国标平板计数法检验巴氏杀菌乳中的大肠菌群的检测结果进行对比验证。[结果]通过实验得出Soleris微生物快速检测系统只需要13.5 h即可出结果,比传统国标方法检出时间大大缩短。[结论]在适宜的条件下,当产品中含有大肠菌群阳性样时,Soleris微生物快速检测系统均能在较短的时间内检出,产品中大肠菌群含菌量越大,检测时间越短,并且与传统国标平板计数法具有良好的一致性,是一种可行的大肠菌群检测方法。     

Bacteriological diagnosis with Petrifilm of mastitis pathogens in milk samples from each quarter and bulk milk samples

Three experiments were conducted to evaluate four different Petrifllm products (3M, Neuss) for detection of mastitis pathogens in quarter and bulk milk samples, comparing them to the results of standard microbiological techniques. The aim of experiment 1 was to determine the sensitivity of 3M Rapid Coliform Count Plate in identifying clinical mastitis cases caused by coliform bacteria. Within 12 h of incubation, three times more coliform bacteria could be identified with Petrifilm than with the standard technique. For a valid result, milk samples must be free of contamination. Experiment 2 focused on whether Petrifilm was able to monitor S. aureus on bulk milk level in herds being infected with this pathogen. In relation to the gold standard (combination of both procedures (standard and Petrifilm, prevalence 52%), sensitivity for the standard procedure amounted to 15.4% and to 94% for Petrifilm. In Experiment 3 the combination of several Petrifilm (RUEGG, 2004) was compared with the standard diagnostic technique (gold standard). Sensitivity of the Petrifilm method approached the assumed gold standard to 43% and specificity to 29%. The positive predictive value of 28% showed that both procedures are not directly comparable with each other. Due to the definition of a gold standard, the weaknesses of the classical technique can be interpreted as a disadvantage of the Petrifilm procedure. The strength of the available Petrifilm as mastitis diagnostic tools is the identification of S. aureus and coliform microorganisms, moreover E. coli.     

The role of lysozyme in killing and lysis of coliform bacteria in the bovine animal 1. Serum and milk concentrations of lysozyme and susceptibility of coliform strains to its action

Concentrations of lysozyme were determined in 206 bovine sera and 37 bulk-tank milks. Detectable levels were not found in 46.6% or 96 sera, 38.3% (79 sera) had less than 2.5 μg/ml, 12.1% (25 sera) had concentrations of 2.5 to 25 μg/ml and 2.9% (6 sera) had concentrations greater than 25.0 μg/ml. Only one milk sample had any detectable lysozyme (0.5 μg/ml) by the method used.Lysis by bovine sera of washed coliform bacteria previously determined to be resistant or sensitive to killing by bovine serum was tested in various buffer systems. No correlation between killing by serum and sensitivity to lysis by lysozyme was found. EDTA markedly potentiated serum lysis in the presence of added lysozyme. Lysozyme itself was not lytic.Added lysozyme did not potentiate killing of the coliforms by bovine serum when tested by direct plate counts or by spectrophotometric growth assay.These in vitor results suggest that lysozyme may have limited importance as a protective agent against coliform bacteria in vivo.     

分光光度法测定婴幼儿配方乳粉中磷含量的不确定度评定

运用测量不确定度的基本方法和程序,建立分光光度法测定婴幼儿配方乳粉中磷含量的测量不确定度评定的数学模型,对测量过程中的不确定度来源进行逐项分析和合成,得出分光光度法测定婴幼儿配方乳粉中磷含量的不确定度评定结果.结果表明:当婴幼儿配方乳粉中的磷含量为180.5mg/100g时,扩展不确定度为3.3mg/100g.     

生乳的微生物检测

在乳和乳制品的生产过程中消毒是一个重要环节。目前市售鲜乳主要为巴氏杀菌乳和UHT灭菌乳，但也有一部分未经消毒的散装生牛乳。实验采用国家规定的标准办法检验未经消毒的生牛乳中的细菌总数和犬肠菌群数。实验证明，未经消毒的生牛乳中的细菌总数是大大超标的．犬肠菌群虽然为阴性，但其中含有致病性葡萄球菌和链球菌。因此饮用这种乳对人们的身体健康有极大危害。     

乳粉溶解度测定的不确定度评定

[目的]研究乳粉溶解度的不确定度评定。[方法]根据《GB 5413.29—2010 食品安全国家标准婴幼儿食品和乳品溶解性的测定》中的第二法溶解度的测定来测定乳粉的溶解度。通过分析不确定度的来源,建立完整的数学模型,对模型中的各影响因素的不确定度进行评定和计算,合成相对标准不确定度,计算相对扩展不确定度。[结果]当取置信度为95%时,得到的乳粉溶解度：X=（99.97±1.60） g/100 g,取k=2,扩展不确定度为U=1.60 g/100 g。[结论]该方法可以为乳粉溶解度的不确定度评定提供参考依据。     

仪器法检测碱性磷酸酶的测量不确定度的评估

[目的]探讨仪器法检测碱性磷酸酶（alkaline phosphatase,ALP）的测量不确定度的评估方法。[方法]结合ALP的检测原理,参照JJF 1059.1—2012《测量不确定度评定与表示》有关内容,评估检测中所涉及的不确定度分量的来源,并明确各分量的大小,从而确定合成不确定度与拓展不确定度。[结果]ALP的合成不确定度为5.89%,取95%置信水平时,拓展不确定度为11.78%（k=2）。[结论]通过对ALP检测分析过程中所涉及的环节进行分析,确定各环节的不确定度分量,可更系统全面地反映检测结果,并根据相关不确定度分量的大小有针对性地降低其量值,持续改进检测质量。     

乳粉中金黄色葡萄球菌测定不确定度评定

[目的]评估乳粉中金黄色葡萄球菌检测结果的不确定度。[方法]依照食品安全国家标准《GB 4789.10—2016 食品微生物学检测 金黄色葡萄球菌检验》中的第二法和《JJF 1059.1—2012测量不确定度评定与表示》,以标准质控品的奶粉为例,分析样品制备、稀释过程、加样过程及重复性检测引入的不确定度。[结果]乳粉中金黄色葡萄球菌检测结果的扩增不确定度U=0.108。[结论]本研究建立的方法适合类检验条件下金黄色葡萄球菌不确定的评定。     

Evaluation of a rapid coliform detection kit from clinical mastitis milk using colloidal gold nanoparticle–based immunochromatographic strips

The accurate identification of mastitis‐causing bacteria assists in effective management by both dairy farmers and veterinarians and can be used to implement the selective use of antimicrobials for treatment. The purpose of this study was to evaluate the ability of our developed anti–ribosomal protein-L7/L12 antibody–coated immunochromatographic strip (ICS) test to detect coliforms in milk by comparing the results with the bacteriological culture method. We investigated the performance of the ICS test as compared with the bacteriological culture method using 308 milk samples from clinical bovine mastitis. First, to determine the optimal ICS test cutoff point for detecting coliform mastitis, we developed a receiver-operating characteristic curve. The result showed that the cutoff point was at 0.5 of our index. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value of the ICS test were 81.3%, 84.8%, 69.2%, and 91.54%, respectively. As the clinical signs increased in severity, the F-measure, a weighted harmonic mean of the sensitivity and overall PPV performance, increased. Because it is especially important to treat clinical mastitis appropriately in the early stages of detection, the ICS test, which can be used by both dairy farmers and veterinarians on dairy farms, is considered to be a useful tool for detecting coliform mastitis, which often presents with severe signs.