For Users of HPLC Systems
Buffer Solution Preparation Mode (AP-W Series only)
- Recipes for 13 commonly used buffer solutions are included as standard
Preparation recipes for commonly used buffer solutions are provided as standard.
e.g. disodium phosphate, sodium acid citrate
- New buffer solution recipes can be registered
If a buffer solution is not registered by default, it can be newly registered.
- Instructions are shown on the display
The target weighing value is shown on the display and analog bar in order to compare the target with the current weight. Manual calculation is not needed.
- Record function
Record output with date, time and operator name.
The pH level of mobile phase (eluent) solutions used in liquid chromatographs is adjusted to improve separation of components and extend the life of columns. This pH adjustment process is performed using a buffer solution.
Currently, the most common method is using a pH meter to measure the pH as the solution is prepared; however, this process requires considerable time and effort, which can cause operational bottlenecks.
An alternative method does not require a pH meter. It involves preparing solutions by weighing fixed theoretically calculated quantities of an acid and base.
AP series supports weighing these acids and bases. If the type and quantity of the buffer solution are specified, the balance displays the type and quantity of sample that should be weighed. Then the buffer solution can be prepared easily by adding water to the specified quantity of sample weighed accordingly.
When weighing and preparing 50 mM of di-sodium hydrogen phosphate, 2-hydrate and 50 mM of sodium dihydrogenphosphate, 2-hydrate in order to prepare 3 L of 100 mM phosphoric acid (sodium) buffer solution at pH=2.1:
Sample Preparation (AP-W Series only)
When preparing a standard solution from a particular component, the standard powder for this component will be a hydrochloride or a hydrate.
Preparing a standard solution of the target component at a desired requires difficult calculations prior to weighing it. With the AP series, however, the required weight value is automatically calculated, so it can be weighed without performing manual calculations.
Standard sample of Amitriptyline is Amitriptyline Hydrochloride.
Calculation is essential to determine part of Acidum hydrochloricum by molecular weight in order to make a 100 mg/mL Amitriptyline solution.
Molecular weight of Amitriptyline: 277.4
Molecular weight of Acidum hydrochloricum: 36.5
Molecular weight of Amitriptyline Hydrochloride: 277.4 + 36.5 = 313.9
To compare the molecular weight of Amitriptyline Hydrochloride with Amitriptyline, the following calculation is necessary.
313.9/277.4 = 1.132
The molecular weight of Amitriptyline Hydrochloride is 1.132 times of Amitriptyline.
So, if 25mg of Amitriptyline is used, it follows that the weight of Amitriptyline Hydrochloride should be: 25 mg x 1.132 = 28.3 mg.
Hence, 28.3 mg of Amitriptyline Hydrochloride is needed to make the correct standard solution.