Issue 问题
The presence of ghost peaks can be a symptom of a system contamination issue, caused by accumulation of sample and/or foreign substances in the flow path. It is critical for high sensitivity LC/MS and LC/MS/MS.
鬼峰的存在可能是由于样品和/或异物在流路中积累而导致的系统污染问题的症状。这对于高灵敏度LC/MS和LC/MS/MS至关重要。
In addition to the presence of ghost peaks, some increase in pressure may have been noticed.
除了鬼峰的存在之外,可能已经注意到压力的一些增加。
Background 背景
One common source of contamination and carry-over of peaks from previous sample runs can be caused by worn or contaminated:
一个常见的污染源和先前样品运行中峰的残留可能是由磨损或污染引起的:
Needle, 针头,
Needle seat, 针座,
Rotor seal, 转子密封,
Injection valve (stator head).
喷射阀(定子头)。
These parts are all on the sample and flow path, as seen on Figure 1:
这些部件均位于样品和流路上,如图1所示:
Figure 1. Flow Path of Sampler in Mainpass
图1.进样器流路
1. Sample 2. From Pump to Injection Valve, 3. Metering device, 4. Sample Loop, 5. Needle, Needle Seat, 6. To Column from Injection Valve, 7. Solvent, 8. Wash pump, 9. Wash Port
1.示例2拉从泵到喷射阀,3。计量装置,4.样品环,5.针,针座,6。从进样阀至色谱柱,7.溶剂,8.清洗泵,9.洗涤端口
Requirements 要求
Disconnect the column from the instrument and replace it with a restriction capillary, then perform a blank run on your LC system.
断开色谱柱与仪器的连接,并将其更换为限流毛细管,然后在LC系统上执行空白运行。
Confirmation: A blank run is a run with only injecting the solvent that samples are dissolved in. |
A comparison of column vs. no-column blank runs should identify whether the noted contamination is due to carry over from the column. If the ghost peaks still appear on the blank run, then the contamination comes from the system and not the column.
色谱柱与无色谱柱空白运行的比较应确定所述污染是否是由于色谱柱的残留所致。如果空白运行中仍出现鬼峰,则污染来自系统而非色谱柱。
The key system components should be checked thoroughly – such as the column inlet or the autosampler.
应彻底检查关键系统组件-如色谱柱入口或自动进样器。
Items Required 需要的产品
When facing a contamination, one of its origins can be found in the autosampler, the following parts should be exchanged in this order:
当面临污染时,其来源之一可以在自动进样器中找到,应按此顺序更换以下部件:
Needle, needle seat 针、针座
Rotor seal 转子密封
Sample loop 采样环
Stator head 定子头
A full list of the required parts for the particular model of autosampler can be found here.
特定型号自动进样器所需部件的完整列表可在此处找到。
Tips: This troubleshooting should be carried out with freshly made mobile phase and samples (with new vials). If a needle wash is installed, please flush the wash solvent bottle, clean the wash port, and replace the wash solvent. |
Steps to Follow 要遵循的步骤
After completing each of the following steps, a blank run should be performed. If the contamination is still present, proceed to the next step.
完成以下每个步骤后,应进行空白运行。如果污染物仍然存在,继续下一步。
Change the needle and the needle seat. See the following articles for changing:
更换针和针座。请参阅以下条款进行更改:
The G7129X Vialsampler's needle and needle seat,
G7129 X小瓶取样器的针头和针座,
The G7167X Multisampler's needle and needle seat,
G7167 X多功能采样器的针头和针座,
The G4226x/G1367E Autosampler's the needle and needle seat, or
G4226 x/G1367 E自动进样器的针头和针座,或
The G1367A-D Autosampler's needle and needle seat,
G1367 A-D自动进样器的针头和针座,
Replace the sample loop.
更换样品定量环。
Bypass the autosampler by joining ports #1 and #6 of the injection valve with a union or a short capillary tubing.
通过将进样阀的端口#1和#6与接头或短毛细管连接,绕过自动进样器。
Purge for 5 mins at with high organic solvents (i.e isopropanol).
用高有机溶剂(即异丙醇)静置5分钟。
Sonicate the injection valve rotor seal, stator face, and stator head.
超声处理进样阀转子密封、定子面和定子头。
Change the rotor seal.
更换转子密封。
Change the stator head.
更换定子头。
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