Disclosure of Invention
The invention aims to provide a method for preparing a solution of a volatile solute, which aims to solve the technical problem of low weighing accuracy in the preparation of the solution of the volatile solute in the prior art.
In order to solve the technical problem, the preparation method of the volatile solute solution provided by the invention comprises the following steps:
weighing a closed weighing container filled with a solvent;
extracting a preset amount of solute in a liquid state;
pumping the extracted solute into the weighing container;
and weighing the weighing container after the solute is beaten in.
Further, before the preset amount of the solute in the liquid state is extracted, the method further comprises the following steps: the best effect is achieved when the operating environment temperature is below-4 ℃, a sealed solute bottle containing liquid solute is placed in a heat preservation container, and the temperature in the heat preservation container is lower than the boiling temperature of the solute, so that the solute in the solute bottle is kept in a liquid state. The heat retainer can also be an ice bag or dry ice.
Further, the step of extracting a preset amount of solute in a liquid state specifically comprises the following steps: inserting a needle of a liquid transferring device into a solute bottle, extracting a preset amount of solute, inverting the solute bottle and the liquid transferring device to enable the needle of the liquid transferring device to be higher than the liquid in the solute bottle, operating the liquid transferring device to extract a preset amount of gas, and rapidly pulling out the needle of the liquid transferring device from the solute bottle.
Further, the step of extracting the solute with the preset amount specifically comprises the following steps: and pumping a small amount of solute into the liquid transfer device, pumping the solute in the liquid transfer device back into the solute bottle, and pumping a preset amount of solute into the liquid transfer device.
Further, the method also comprises the following steps after weighing the weighing container with the solute injected into the weighing container: using a pipettor to extract all liquid in the weighing container;
the liquid in the liquid transfer device is driven into a preparation container containing a preset amount of solvent.
Further, the method for extracting all liquid in the weighing container by using the pipettor specifically comprises the following steps: and inserting the pipette needle into the weighing container for extraction, and pulling out the pipette needle from the weighing container when the pressure in the weighing container is less than the external atmospheric pressure.
Further, the method for extracting all liquid in the weighing container by using the pipettor specifically comprises the following steps: the method comprises the steps of inserting a pipette needle into a weighing container for extraction, after all liquid is extracted, continuing to operate the pipette to extract gas with a preset amount, inverting the pipette and the weighing container to enable the pipette to be below the weighing container, and rapidly pulling out the pipette needle from the weighing container.
Further, the preparation method of the heat-insulating container comprises the following steps: putting an object into a container filled with liquid, so that the liquid in the container partially submerges the object, putting the container into a refrigerator for freezing until the liquid is completely solidified, taking the container out of the refrigerator, taking the object out of the container, and forming the container into the heat-preservation container, wherein the container is internally provided with a groove.
Further, weigh the container including weighing the bottle and sealed lid, sealed lid is established in the opening of weighing the bottle and is located will weigh the bottle and seal, and the material of sealed lid is silica gel.
Further, the step of pumping the extracted solute into the weighing container comprises the following steps: and pumping the extracted solute into a weighing container by using a liquid transfer device, inserting a needle of the liquid transfer device into the weighing container, positioning the needle above the liquid level in the weighing container, and pumping the solute in the liquid transfer device into the weighing container.
By adopting the technical scheme, the invention has the following beneficial effects:
the method for preparing the solution of the volatile solute solves the weighing difficulty of volatile standard substances, avoids volatilization of main components in the weighing process, and avoids instability of balance reading caused by volatilization, so that the weighing result is more accurate and infinitely close to the true value, the weighing accuracy is high, and the prepared solution is high in accuracy. The standard substance has good uniformity through actual detection, and guarantees quality control and quantity detection in enterprises such as medical instruments, hollow capsules, plastic products and the like; the configuration accuracy and the detection reliability are greatly improved.
Detailed Description
The technical solutions of the present invention will be described clearly and completely below, and it should be apparent that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The present invention will be further explained with reference to specific embodiments.
The preparation method of the solution of the volatile solute provided by the embodiment comprises the following steps:
weighing a closed weighing container filled with a solvent;
extracting a preset amount of solute in a liquid state;
pumping the extracted solute into the weighing container;
and weighing the weighing container after the solute is beaten in.
In the solution preparation method provided by this embodiment, the weighing container containing the solvent is weighed, the liquid solute is pumped into the weighing container, so that the solute is dissolved in the solvent, the weighing container is weighed, and the weight of the extracted solute can be obtained by comparing the two weights of the weighing container. This embodiment adopts and squeezes the solute into the mode of weighing after the solvent for the solute dissolves to the solvent after, has reduced the volatilization of solute, the operation of being convenient for, it is high to weigh the accuracy, and the solution accuracy of configuration is high. The invention is suitable for preparing the solution of volatile solute, in particular to the solute which is gaseous at normal temperature, such as ethylene oxide and the like.
Preferably, the solute is ethylene oxide. The solvent is water. The solvent can also be DMSO, polyethylene glycol 200, glycerol triacetate, toluene, dichloromethane, isooctane, etc.
Specifically, when the ambient temperature is less than-4 ℃, when the extracted solute is driven into the weighing container by the liquid transfer device, the needle of the liquid transfer device is positioned above the liquid level in the weighing container, so that the needle is prevented from contacting with the liquid in the weighing container, and the weighing precision can be improved. Before the needle is pulled out of the weighing container, the needle is contacted with the bottle wall of the weighing container to remove the residual liquid on the needle tip.
On the basis of the above embodiment, further, before the preset amount of the solute in the liquid state is extracted, the method further includes the following steps: the method comprises the steps of placing a sealed solute bottle containing liquid solute in a heat preservation container, wherein the heat preservation container can be an ice box or dry ice, and the temperature in the heat preservation container is lower than the boiling temperature of the solute so as to keep the solute in the solute bottle in a liquid state. The heat preservation container can make the solute in the solute bottle keep for liquid, avoids weighing in-process solute to volatilize to be convenient for draw the solute.
Specifically, the preparation method of the heat-insulating container comprises the following steps: putting an object into a container filled with liquid, so that the liquid in the container partially submerges the object, putting the container into a refrigerator for freezing until the liquid is completely solidified, taking the container out of the refrigerator, taking the object out of the container, and forming the container into the heat-preservation container, wherein the container is internally provided with a groove. The method is adopted to conveniently and rapidly prepare the heat preservation container, the heat preservation container can be an ice bag or dry ice, preferably, the object can be a bottle body, a weight is placed in the bottle body, liquid in the container can be water, the bottle body is placed in the water in the container, so that two thirds of the height of the bottle body is submerged, the container is placed in a refrigerator to be frozen until the water is solidified into ice, the container is taken out of the refrigerator, then the bottle body is taken out of the container, and after the bottle body is taken out, the part of the container, which is used for accommodating the bottle body, is formed into a groove shape, namely the heat preservation container.
On the basis of the above embodiment, further, the extracting a preset amount of the solute in the liquid state specifically includes the following steps: inserting a needle of a liquid transferring device into a solute bottle, extracting a preset amount of solute, inverting the solute bottle and the liquid transferring device to enable the needle of the liquid transferring device to be higher than the liquid in the solute bottle, operating the liquid transferring device to extract a preset amount of gas, and rapidly pulling out the needle of the liquid transferring device from the solute bottle. Inverting the solute bottle and the pipette means the solute bottle is up and the pipette is down. After inversion, the needle head of the liquid shifter can be positioned above the liquid in the solute bottle, air in the solute bottle is continuously extracted to enter the needle head, and then the needle head is pulled out of the solute bottle. The reason why the operation mode is adopted is that after the needle of the liquid transfer device is pulled out of the solute bottle, the solute in the liquid transfer device is partially gasified and volatilized due to the high temperature of the external air, and the volatilized gas is sprayed out through the needle. And after adopting above-mentioned operation, the outside one section distance of syringe needle is the air, when volatilizing gas in the pipettor passes through the outside blowout of syringe needle, the first-selected spun is the inside air of syringe needle, just from the blowout in the pipettor when the air blowout is finished volatilizing gas, has reduced the blowout of volatilizing gas in the pipettor to if the operator operation when faster, can realize in the pipettor volatilizing gas when not blowout promptly by being squeezed into weigh the container in, thereby reduced the volatilization of weighing in-process solute.
The pipette in the present invention may be a syringe or a pipette gun having a needle, and preferably, the pipette is a syringe.
On the basis of the above embodiment, further, the extracting the solute by the preset amount specifically includes the following steps: and pumping a small amount of solute into the liquid transfer device, pumping the solute in the liquid transfer device back into the solute bottle, and pumping a preset amount of solute into the liquid transfer device. Because the liquid temperature in the solute bottle is lower, the pipettor temperature is higher, can lead to liquid solute to volatilize because of the temperature becomes high after the pipettor extracts liquid solute. In the embodiment, during operation, a small amount of solute is extracted into the liquid transfer device, the temperature in the liquid transfer device is reduced due to the lower temperature of the solute, the solute in the liquid transfer device is volatilized into gas, the gaseous solute in the liquid transfer device is pumped back into the solute bottle, the liquid solute with the preset amount is extracted into the solute bottle, and the liquid solute cannot be volatilized as gas after entering the liquid transfer device due to the temperature reduction of the liquid transfer device, so that the volatilization of the solute is reduced.
On the basis of the above embodiment, further, after weighing the weighing container with the solute therein, the method further includes the following steps:
preferably the ambient temperature should be controlled below 4 ℃.
Using a pipettor to extract all liquid in the weighing container;
the liquid in the liquid transfer device is driven into a preparation container containing a preset amount of solvent.
In this embodiment, all the liquid in the weighing container is transferred to the preparation container and diluted to a predetermined density.
Further, after the preparation container is diluted to a preset concentration, the preparation container is refrigerated for a preset time, the solution in the preparation container is subpackaged into ampoule bottles, and then the ampoule bottles are sealed by melting and stored in a freezing way.
On the basis of the above embodiment, further, after the liquid in the pipette is driven into the preparation container containing the preset amount of the solvent, the method further includes the following steps: the weighing container was cleaned with a solvent, and the cleaned liquid was transferred into a preparation container. Preferably, the weighing vessel is repeatedly cleaned a number of times to ensure that the solute in the weighing vessel is transferred into the dispensing vessel.
On the basis of the above embodiment, further, the extracting all the liquid in the weighing container by using the pipette specifically includes the following steps: and inserting the pipette needle into the weighing container for extraction, and pulling out the pipette needle from the weighing container when the pressure in the weighing container is less than the external atmospheric pressure. Because the solvent is pumped into the weighing container, the internal pressure of the weighing container is increased, and when the liquid in the weighing container is pumped out, the internal pressure of the weighing container is ensured to be negative (namely, the internal pressure of the container is less than the external atmospheric pressure), so that the gas in the weighing container can be prevented from being sprayed out after the needle head is pulled out.
On the basis of the above embodiment, further, the extracting all the liquid in the weighing container by using the pipette specifically includes the following steps: the method comprises the steps of inserting a pipette needle into a weighing container for extraction, after all liquid is extracted, continuing to operate the pipette to extract air with a preset amount, inverting the pipette and the weighing container to enable the pipette to be below the weighing container, and rapidly pulling out the pipette needle from the weighing container. Because the pipettor extracts the air of the preset amount, a section of distance in the needle head is the air, when the pipettor needle head is pulled out and is transferred, when the solute in the pipettor is volatilized and is outwards sprayed, the air in the pipettor needle head is outwards sprayed, and the volatilization of the solute is reduced.
On the basis of the embodiment, further, the weighing container comprises a weighing bottle body and a sealing cover, the sealing cover is arranged at the opening of the weighing bottle body to seal the weighing bottle body, and the sealing cover is made of silica gel. The sealed lid of silica gel is convenient for pipettor syringe needle and is inserted into the extraction and squeeze into, and convenient operation is applicable to the solution's of solvent for water preparation. The solute bottle can also adopt the structural form of a bottle body and a silica gel sealing cover. Preferably, the sealing cover is composed of a silicone rubber and an aluminum gland, the silicone rubber being located at the center of the aluminum gland.
The solution prepared by the method provided by the invention is detected by a headspace gas chromatography method and evaluated by an analysis of variance method, and the result uniformity is good. Therefore, the compound can be used as a standard substance, can greatly improve the reliability and the accuracy, and has important significance for detecting and analyzing the quantity transmission and quality control of a laboratory.
The solvent is water, the solute is ethylene oxide as a preferred embodiment, and the preparation process comprises the following steps:
step a: preparing a heat preservation container: putting a heavy object into the bottle body, putting the bottle body into a container filled with water to submerge the bottle body to two thirds of the height, putting the container into a refrigerator to freeze until the water freezes, taking out the completely solidified container from the refrigerator, taking out the solidified bottle body from the container, and forming a groove in the container.
Step b: taking out the solute bottle containing volatile ethylene oxide from the refrigerator, and inserting the solute bottle into the groove in the container for later use;
step c: transferring a certain amount of solvent (water) into a weighing container (a headspace glass bottle with a silica gel sealing cover), and putting the weighing container on a balance to return to zero;
step d: and (3) extracting a certain amount of solute in the solute bottle, quickly pumping the solute into a weighing container (a headspace glass bottle containing a blank aqueous solvent) (the room temperature in the operation process needs to be less than or equal to 4 ℃ or in a refrigeration house), and weighing.
When the preparation concentration is 2000 mug/mL, a 2mL injector is needed to accurately absorb 1.2mL of ethylene oxide (about 1 g), the ethylene oxide is quickly injected into a headspace bottle with blank solvent water (the room temperature is not more than 4 ℃ in the operation process or the operation is carried out in a cold storage), the mixture is slightly shaken (the liquid is not required to be attached to a headspace cover), so that the ethylene oxide raw material is fully dissolved into the solvent, the mixture is placed on a balance, and after the degree is stable, the indication value is recorded.
The liquid in the weighing container is transferred into a 500mL volumetric flask (the weighing amount is 1g, the concentration is 2000 mug/mL) by using a 20mL syringe (with a 80mm needle head), the weighing container (a headspace bottle structure) needs to be cleaned for more than or equal to 5 times by using a blank hydrosolvent, the blank hydrosolvent needs to contact with a bottle cap as little as possible during the first three times, and the blank hydrosolvent needs to be fully shaken after being injected into the solvent during the last two times of cleaning by using the solvent, and then the whole weighing container is transferred into a preparation container (volumetric flask) for constant volume.
Step e: the solution poured into the weighing container was transferred into a preparation container (volumetric flask with empty white water) by a syringe, and diluted to a target volume and a constant volume.
Step f: subpackaging the solution standard substance in the preparation container into ampoule bottles, sealing by melting by using an ampoule bottle sealing machine, and freezing for storage.
Step g: and extracting a certain amount of samples from the finished product by adopting a random number table method, taking two characters from each sample, detecting by adopting a headspace gas chromatography (FID), and evaluating the uniformity by adopting an analysis of variance method.
The following is that the solvent is water, the solute is ethylene oxide solution to detect, namely, 11 samples are extracted from the finished product by a random number table method, each sample takes two characters, headspace gas chromatography (FID) is adopted to detect, variance analysis is adopted to evaluate the uniformity, and the uniformity of the sample is judged by comparing the F test value with the F critical value. The ethylene oxide homogeneity test in water is shown in table 1 below:
TABLE 1
The above data show that the homogeneity of the ethylene oxide characteristic values in water passes the F test, indicating that the homogeneity of the standard is good.
In conclusion, the standard solution preparation method provided by the invention solves the weighing difficulty of volatile standard substances, avoids volatilization of main components in the weighing process, and simultaneously avoids instability of balance reading caused by volatilization, so that the weighing result is more accurate and infinitely approaches to the true value; the standard substance has good uniformity through actual detection, and guarantees quality control and quantity detection in enterprises such as medical instruments, hollow capsules and plastic products. The configuration accuracy and the detection reliability are greatly improved.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.