Currently, a large number of agricultural products samples (other chemical products, organic acids, etc.) need to be tested by liquid chromatography and gas chromatography every year. Due to the large number of samples, a large number of injection bottles need to be cleaned during the detection process, which not only wastes time and reduces work efficiency, but also sometimes causes deviations in experimental results because the cleanliness of the cleaned sample bottles does not meet the requirements.
Chromatographic sampling bottles are mainly made of glass, and rarely are made of plastic. Disposable sampling bottles are costly, wasteful, and pollute the environment. Most laboratories clean and reuse the sampling bottles.
At present, the commonly used methods for cleaning sampling bottles in laboratories are to add washing powder, detergent, organic solvents and acid-base washing liquid, and then scrub them with customized small test tubes.
This conventional brushing method has many disadvantages: it uses a large amount of detergent and water, takes a long time to wash, and easily leaves dead corners. If it is a plastic injection bottle, it is easy to leave brush marks on the inner bottle wall. , occupying a lot of human resources. For glassware seriously contaminated by lipid and protein residues, alkaline lysis solution can be used to clean it and achieve good results.
When analyzing samples by LC/MS/MS, cleaning of the injection bottle is very important. According to the glass instrument washing method, choose the cleaning method according to the degree of contamination. There is no fixed mode.
Method summary:
Option 1:
1. Pour out the test solution in the bottle
2. Immerse it all in 95% alcohol. Pour it dry after ultrasonic washing twice, because alcohol easily enters the 1.5mL vial and is miscible with most organic solvents to achieve the cleaning effect.
3. Pour in clean water and ultrasonically wash twice.
4. Pour out the lotion in the bottle and bake at 110 degrees Celsius for 1 to 2 hours. Never bake at high temperatures.
5. Cool and save.
Option 2:
1. Rinse several times with tap water
2. Place in a beaker filled with pure water (Millipore water machine) and sonicate for 15 minutes
3. Change the water and sonicate for 15 minutes again
4. Soak in a beaker filled with absolute ethanol (Sinopharm Group, analytical grade)
5 .Finally take it out and let it dry naturally.
Option 3:
1. First soak in methanol (chromatographically pure) ((some waste (⊙o⊙))), and ultrasonically clean for 20 minutes, and then pour the methanol Dry.
2. Fill the sampling bottle with water, clean it ultrasonically for 20 minutes, and then drain the water.
3. Dry the sampling bottle
p>Option 4:
(The first method) is usually rinsed and dried with water first, then soaked in potassium dichromate sulfate lotion
(No. Type 2) The washing method of the injection bottle is the same as that of making liquid phase. First, soak it with medical alcohol for more than 4 hours, then ultrasonic for half an hour, then pour out the medical alcohol, use water for half an hour, and then use water. Just rinse and dry it
Option 5:
1. If the cost is sufficient, it is best to use new ones every time.
2. If it is to be reused, the cleaning method is also very important. First, soak it in a strong oxidizing cleaning solution (potassium dichromate) for 24 hours, then clean it three times with deionized water under ultrasonic conditions, and finally Wash once with methanol, dry and ready for use.
3. The bottle pad must be replaced with a new one, especially when analyzing pesticide residues, otherwise it will affect the quantitative results. However, if conditions permit, try to use disposable consumables. For example, if you use a disposable polytetrafluoroethylene inner tube or a domestic plastic inner tube (about 0.1 yuan/piece), the sample bottle can be used repeatedly and does not need to be cleaned.
Option 6:
If you still prefer to carry forward the good style of diligence and frugality, the suggestions are as follows:
(1) ? Cumbersome cleaning, solid results:
No1. After using the sample bottle, first rinse the sample bottle with running water to flush away the remaining sample (you can also shake it with your hands);
No2. Then Put the sample bottle into the potassium dichromate washing solution. When it accumulates to a certain amount or when you are in a good mood one day, take it out of the washing solution tank, place it in a kitchen plastic sieve, and rinse it thoroughly with tap water. You can repeat it in the middle. Sieve and shake;
No3. After rinsing, ultrasonic cleaning with tap water for about 3 times, it is best to shake out the water in the sample bottle after each ultrasonic cleaning;
No4. Then Use triple distilled water (or purified water, deionized water) and ultrasonic cleaning three times with 1.3;
No5. Then use chromatographically pure methanol to ultrasonic clean 2 to 3 times. It is also best to clean the sample bottle after each cleaning. Throw out the methanol;
No.6. Place the sample bottle in the oven and dry it at about 80 degrees before use.
(2) ? Purchase sample bottles marked with different colors: I wonder if you have noticed that there is a small colored mark on the sample bottle. It is not just for appearance, but has its own meaning. When purchasing, it is best to buy bottles in several different colors.
For example:
Your laboratory opens two projects A and B at the same time. For the first time, project A uses white sample bottles, and project B uses blue sample bottles. After cleaning according to the above method, for the second experiment, use blue sample bottles for project A, white sample bottles for project B, and so on, which can effectively avoid the trouble caused by contamination to your work.