zjchen3189 2008/09/28
[quote]原文由 [B]redanqi[/B] 发表: G. SCREENING CRITERIA 1. The retention time must match that of an external standard within 5%. 2. The melamine product ion abundance ratios must match that of an external standard within 20% relative. Example calculation: Melamine ion ratio = (area of m/z 127 to 85 peak) ÷ (area of m/z 127 to 68 peak) Note: Most mass spectrometers calculate the reciprocal of the above and state it as a percentage, which is equally valid. Passing ion ratio of a sample = ion ratio of a standard ± (0.2 * ion ratio of a standard) 3. The solvent blank, ACN:H2O (1:1, v/v), injected after the standard curve must be negative for melamine (no peak within the retention time window with passing ion ratio), demonstrating no carryover. 4. The positive tissue control must be positive for melamine (meeting retention time and ion ratio criteria). 5. The negative tissue control must not contain melamine at levels higher than 10% of the positive tissue control. Melamine peaks meeting the retention time and ion ratio criteria must be compared to the positive tissue control. The Internal standard is used, the melamine quantification peak area (m/z 127 to 85) divided by the internal standard peak area (m/z 130 to 87) must be less than or equal to10% of that of the positive tissue control. 6. For a sample to be screen positive, it must be found to contain melamine at or above the 50ppb minimum proficiency level of this analytical method. The internal standard is used, the melamine quantification peak area (m/z 127 to 85) divided by the internal standard peak area (m/z 130 to 87) must be greater than or equal to that of the positive tissue control.[/quote] G. 筛选标准 1. 保留时间与标准偏差必须在5%之内。 2. 三聚氰胺离子富集与标准偏差必须在20%之内。 例子演算: 三聚氰胺离子比率= (m/z 127到85峰面积) ÷ (m/z 127到68峰面积) 注:大多数质谱计算的是上式的倒数,并标记为百分比,也是同等有效的。 样品通过离子比率=标样的离子比率±(0.2 * 标样的离子比率) 3.溶剂空白,ACN:H2O(1:1,V/V),必须在标准曲线三聚氰胺完全检不出之后才注入(符合通过离子比率在保留时间段不出峰),并显示无残留。多数质谱仪计算相互在上面并且陈述它作为百分比,是相等地合法的。 4. 以保留时间和离子比率为确认标准。 5. 符合保留时间和离子比率标准的三聚氰胺峰面积必须与内标控制比较。 使用内标,内标峰面积(m/z 127到85)划分的峰面积的三聚氰胺量化(m/z 130到87)必须是小于或等于10%标准样品峰面积。 6. 为了定性分析或检测三聚氰胺含量<50ppb水平的样品。使用内标,内标峰面积(m/z 127到85)划分的高峰地区的三聚氰胺量化(m/z 130到87)必须是大于或等于标准样品峰面积。
风之彩 2008/10/06
G. SCREENING CRITERIA [color=#DC143C]筛选标准[/color] 1. The retention time must match that of an external standard within 5%. [color=#DC143C]保留时间必须在外加标准品保留时间的正负5%以内。[/color] 2. The melamine product ion abundance ratios must match that of an external standard within 20% relative. [color=#DC143C]三聚氰胺子离子的丰度比必须在(外加)标准品子离子丰度比的20%以内。[/color] Example calculation:[color=#DC143C]举例计算:[/color] Melamine ion ratio = (area of m/z 127 to 85 peak) ÷ (area of m/z 127 to 68 peak) [color=#DC143C]三聚氰胺离子比=(m/z 127-85这对离子的峰面积)÷(m/z 127-68这对离子的峰面积)[/color] Note: Most mass spectrometers calculate the reciprocal of the above and state it as a percentage, which is equally valid. [color=#DC143C]注意:大多数质谱仪能够计算上面式子的倒数并且以百分比的形式表示出来,其实也是同样有意义的。[/color] Passing ion ratio of a sample = ion ratio of a standard ± (0.2 * ion ratio of a standard) [color=#DC143C]一个样品可以通过的离子比=标准品的离子比±(0.2 *这个标准品的离子比)[/color] 3. The solvent blank, ACN:H2O (1:1, v/v), injected after the standard curve must be negative for melamine (no peak within the retention time window with passing ion ratio), demonstrating no carryover. [color=#DC143C]在进完标准曲线以后,要进一针空白溶剂,即乙腈/水(1:1,v/v)溶液,且在三聚氰胺出峰的保留时间位置没有出现离子比合格的峰,来证明没有残留。[/color] 4. The positive tissue control must be positive for melamine (meeting retention time and ion ratio criteria). [color=#DC143C]阳性对照组织样品必须检测三聚氰胺呈阳性,即保留时间和离子比符合检出标准。[/color] 5. The negative tissue control must not contain melamine at levels higher than 10% of the positive tissue control. Melamine peaks meeting the retention time and ion ratio criteria must be compared to the positive tissue control. [color=#DC143C]阴性对照组织样品含有三聚氰胺的量不能高于阳性组织样品含量的10%。即使三聚氰胺的保留时间和离子比符合检出标准也必须和阳性对照样品进行比较。[/color] The Internal standard is used, the melamine quantification peak area (m/z 127 to 85) divided by the internal standard peak area (m/z 130 to 87) must be less than or equal to10% of that of the positive tissue control. [color=#DC143C]检测使用内标,三聚氰胺的定量峰对(m/z 127-85)的峰面积除以内标(m/z 130-87)峰面积的比值必须小于等于阳性组织样品的10%。[/color] 6. For a sample to be screen positive, it must be found to contain melamine at or above the 50ppb minimum proficiency level of this analytical method. [color=#DC143C]如果一个样品被检测呈阳性,那么它的三聚氰胺的含量必然大于或等于这种分析方法的能精确测到的最低浓度-50ppb。[/color]
hendric 2008/09/27
G.筛选准则: 1.保留时间必须与一个外标物偏差不超过5%。 2.该三聚氰胺离子富集比必须和一个外标物相对偏差不超过20%。 计算举例: 三聚氰胺离子富集比= (m/z127到85的峰面积) ÷ (m/z127到68的峰面积) 注意:大多数质谱计算的是上式的倒数,并标记为百分比,也是同等有效的。 样品通过离子比率=标样的离子比率±(0.2 * 标样的离子比率) 3.溶剂空白样,ACN:H2O(1:1,V/V),必须在标准曲线三聚氰胺完全检不出之后才注入(符合通过离子比率在保留时间段不出峰),并显示无残留。
zhuxiugao 2008/09/26
[quote]原文由 [B]redanqi[/B] 发表: 请先翻译附件中文件的A与G部分,最终评分按翻译质量和数量分配,同时欢迎各位版友参与评译,参与者亦有积分 A. INTRODUCTION 1. Theory Melamine is extracted from muscle tissue with a mixture of acetonitrile and water. The extract is cleaned up by liquid/liquid extraction with methylene chloride followed by solid phase extraction (SPE). Melamine is eluted from the SPE cartridge with 5% ammonium hydroxide / methanol, evaporated to dryness, reconstituted with internal standard and 50% acetonitrile / water, and analyzed by LC/MS/MS. 2. Applicability This method is applicable for screening of melamine in swine and poultry muscle at ≥ 50 ppb. [img]https://www.instrument.com.cn/bbs/images/affix.gif[/img][url=http://www.instrument.com.cn/bbs/download.asp?ID=110334]v[/url][/quote] 呵呵,俺先试试这一部分 介绍 1、 理论 三聚氰胺使用乙腈与水的混合物从肌肉组织中萃取,萃取物利用液液萃取方式通过SPE用二氯甲烷净化。三聚氰胺使用5%的氢氧化铵/甲醇从SPE柱中洗脱,蒸发至干燥,用内标物与50%的乙腈/水重新配置成原来的浓度,通过LC/MS/MS分析。 2、 适用范围 本方法适用于快速筛选分析猪与禽肌肉组织中三聚氰胺含量大于等于50ppb。
戈壁明珠 2008/09/27
[quote]原文由 [B]zhuxiugao[/B] 发表: [quote]原文由 [B]redanqi[/B] 发表: 请先翻译附件中文件的A与G部分,最终评分按翻译质量和数量分配,同时欢迎各位版友参与评译,参与者亦有积分 A. INTRODUCTION 1. Theory Melamine is extracted from muscle tissue with a mixture of acetonitrile and water. The extract is cleaned up by liquid/liquid extraction with methylene chloride followed by solid phase extraction (SPE). Melamine is eluted from the SPE cartridge with 5% ammonium hydroxide / methanol, evaporated to dryness, reconstituted with internal standard and 50% acetonitrile / water, and analyzed by LC/MS/MS. 2. Applicability This method is applicable for screening of melamine in swine and poultry muscle at ≥ 50 ppb. [img]https://www.instrument.com.cn/bbs/images/affix.gif[/img][url=http://www.instrument.com.cn/bbs/download.asp?ID=110334]v[/url][/quote] 呵呵,俺先试试这一部分 介绍 1、 理论 三聚氰胺使用乙腈与水的混合物从肌肉组织中萃取,萃取物利用液液萃取方式通过SPE用二氯甲烷净化。三聚氰胺使用5%的氢氧化铵/甲醇从SPE柱中洗脱,蒸发至干燥,用内标物与50%的乙腈/水重新配置成原来的浓度,通过LC/MS/MS分析。 2、 适用范围 本方法适用于快速筛选分析猪与禽肌肉组织中三聚氰胺含量大于等于50ppb。[/quote] 翻译成氢氧化铵好像不妥,应该是氨水要好一点。
附件:
何当奇
第1楼2008/09/26
G. SCREENING CRITERIA
1.
The retention time must match that of an external standard within 5%.
2.
The melamine product ion abundance ratios must match that of an external standard within 20% relative.
Example calculation:
Melamine ion ratio = (area of m/z 127 to 85 peak) ÷ (area of m/z 127 to 68 peak)
Note: Most mass spectrometers calculate the reciprocal of the above and state it as a percentage, which is equally valid.
Passing ion ratio of a sample = ion ratio of a standard ± (0.2 * ion ratio of a standard)
3.
The solvent blank, ACN:H2O (1:1, v/v), injected after the standard curve must be negative for melamine (no peak within the retention time window with passing ion ratio), demonstrating no carryover.
4.
The positive tissue control must be positive for melamine (meeting retention time and ion ratio criteria).
5.
The negative tissue control must not contain melamine at levels higher than 10% of the positive tissue control. Melamine peaks meeting the retention time and ion ratio criteria must be compared to the positive tissue control.
The Internal standard is used, the melamine quantification peak area (m/z 127 to 85) divided by the internal standard peak area (m/z 130 to 87) must be less than or equal to10% of that of the positive tissue control.
6. For a sample to be screen positive, it must be found to contain melamine at or above the 50ppb minimum proficiency level of this analytical method.
The internal standard is used, the melamine quantification peak area (m/z 127 to 85) divided by the internal standard peak area (m/z 130 to 87) must be greater than or equal to that of the positive tissue control.
zhuxiugao
第2楼2008/09/26
呵呵,俺先试试这一部分
介绍
1、 理论
三聚氰胺使用乙腈与水的混合物从肌肉组织中萃取,萃取物利用液液萃取方式通过SPE用二氯甲烷净化。三聚氰胺使用5%的氢氧化铵/甲醇从SPE柱中洗脱,蒸发至干燥,用内标物与50%的乙腈/水重新配置成原来的浓度,通过LC/MS/MS分析。
2、
适用范围
本方法适用于快速筛选分析猪与禽肌肉组织中三聚氰胺含量大于等于50ppb。