如何最小化原子吸收光谱分析中的交叉污染误差？

Atomic Absorption Spectroscopyis capable of providing trace metals analysis in ppm and ppb levels for different elements. It is essential to work in aclean laboratory environment and use inert containersfor collection and storage of samples so that errors due to cross contamination are minimized.

The key factors contributing to sample contamination are:

• Exposure of sample to environment
• Leaching or absorption by container material
• Use of volumetric apparatus for preparing solutions and standards not meeting the cleanliness requirements
• Contamination from reagents, solvents and water used for sample preparations
• 分析师污染样品

Some useful tips to minimize cross contamination of the sample are suggested

• Restrict entry into instrument and sample preparation rooms
• 提供双门入口，带有空气窗帘，以尽量减少外部污染
• The instrument and sample preparation room should have epoxy coated walls and rubber or vinyl coated floor tiles
• Flooring should be mopped at least once every day
• 不要准备样品或将仪器保留在直接ac草稿下
• Closed system sample digestion should be preferred over fume hood open digestion. Do not leave solutions in fume hoods longer than required

Leaching and Absorption by container material

• Use clean glassware for preparing samples and standards
• Use inert container material for trace level analysis

体积仪器的清洁度

• Pipettes, Burettes and dilution apparatus should be clean and dry
• Rinse burettes and pipettes with the solution to be transferred

Contamination from reagents, acids, solvents and water

• 使用高纯度研究等级试剂进行样品制备
• 应新鲜制备水并用于制造溶液，并应通过反渗透系统进行双蒸馏或商业制备
• Keep weighing balance pans and bench clean all the time

Contamination from analyst

• 使用一次性手套和清洁实验室外涂层
• Use face masks when preparing samples and for dilutions
• Never lift sample tubes from top using tongs so as to avoid tongs touching the sample solution. Always use side lifting tongs
• Use shoe covers as street shoes can introduce traces of metallic impurities into the laboratory

已经提供了一些有用的提示，以防止由于样品的交叉污染而导致的错误。在分析超痕量金属分析样品时需要进行更大的护理。

请分享您的经验并通过您的意见提供您的建议。