The headspace sampler operates in a constant heating time mode. The following is the basic procedure. This program satisfies most of the experimental requirements, while other programs are designed for special experimental analysis, so custom analysis methods are discussed in the third item.
Option 1 Each sample is heated a minimum of three analysis times.
The following parameters are used for this item:
1.1 Up to 24 samples run the same time with the linked two item empty method, and up to 21 samples can be used with a single headspace method.
1.2 Each sample is heated at least three times for analysis time. For example, if Analysis + Report + GC Stabilization Time is 20 minutes, then each sample is heated for a minimum of 60 minutes.1.3 The sample equilibration time may be longer than 3 analysis times. For example, if the sample analysis time is 20 minutes, the sample may be heated for 90 minutes longer than 60 minutes.
1.4 All samples use the same headspace method.
Procedure 1 sample is heated at least three times for analysis time
2 In order to run 24 samples, two nearly identical headspace methods must be linked (the only difference between the two methods is the number of samples, which is discussed on the next page). Therefore, to create two identical headspace methods, let us set methods 1 and 2, the following methods are set in the usual way and are not affected by the constant heating time mode, select those parameters and initialize the headspace analysis.
. Headspace sample injection sequence (pressurization, emptying, injection)
. Headspace carrier gas flow
. Headspace auxiliary pressure
. Gas phase analysis conditions
- Carrier gas flow
- Column temperature program
- data processing
3 The REMOTE button on the controller can be controlled (red light), starting with the REMOTE button, and the headspace sampler will automatically start the next run, with or without the READY signal from the GC. After the start of REMOTE, the headspace control can be used to create an interval with the "SAMPLING INTERVAL" button.
- The injection interval can be extended by adjusting the equilibration time on the GC.
4 Alternatively, you can enter the desired value by the [SAMPLING INTERVAL" key to end the injection interval. This value must be greater than the analysis cycle time of the entire GC, and the REMOTE button must be turned off (red light off).
5 The following headspace parameters are used for option 1 when the maximum number of runs is 24.
- Equilibration Time
Balance time (methods 1 and 2): 0 minutes
- Last Vial Number
Number of final vials (method 1): 24
- Last Vial Number
Number of final vials (method 2): 3
- Method Sequence
Method sequence : 1,2
6 Injection position / bottle number is entered as follows
- Method 1: Position 1-24 Injection 1 time
- Method 2: Position 1-3 Injection 1 time
7 When the analysis begins, the first 3 positions in the Headspace Sampler should be empty.
8 The bottle 1-24 of the headspace sampler is loaded into the CHT as shown in Figure 3-1. Two or three weighted bottles should be placed at the end to allow all bottles to move.
9 Rotate the sample tray to position 1 and display it on the LED display. Use the [START / PAUSE" button on the headspace controller to start the analysis.
10 The headspace sampler begins the injection of position 1. Since there is no sample at position 1, a peak-free spectrum is produced. At the time of injection, the * actual sample is the sample that the autosampler adds to position 4 and heats.
11 When the pan is turned to position 2, the vial is automatically added to position 5. When position 2 is injected, position 4 has been heated twice for analysis time and position 5 is heated once.
12 When the pan is turned to position 3, the vial enters position 6. After this blank, the bottle in position 4 has been heated for 3 injections, position 5 is heated 2 times, and position 6 is heated once.
13 As the disc continues to advance, the vial enters position 7, and the sample at position 4 begins to analyze, producing * peaked spectra. When the run is over, the sample at position 5 is heated 3 times, position 6 is hot. 2 times, position 6 was heated once.
14 Continue running until all samples are heated 3 times, starting at time 1-3, and added to samples 22-24. For example, when a No. 22 vial is added, the pan is turned to position 1.
15 When all samples have been analyzed according to Method 1, Method 2 begins with the original parameters of the sample run at positions 1-3. (Method 1 and Method 2 differ in that there is a one-minute delay, which allows samples 22-24 to heat up for 1 more minutes than other bottles. Naturally, it has no major effect on the analysis, but the extra 1 minute will change the area of ??some peaks. Therefore, when analyzing by a single method, the number of samples should be limited to 21), and when the last 3 samples are completed, all 24 samples are analyzed.
Option 2 Each sample is heated at least twice for analysis time.
The following parameters are used for this item:
2 Each sample is heated at least twice for analysis time. For example, if Analysis + Report + GC Stabilization Time is 20 minutes, then each sample is heated for a minimum of 40 minutes.
3 Sample equilibration time may be longer than 2 analysis times. For example, if the sample analysis time is 20 minutes, the sample may be heated for 55 minutes longer than 40 minutes.
4 All samples use the same headspace method
Procedure 2 Sample minimum heating secondary analysis time
1 The program assumes that 16 samples are to be run.
2 In order to run 16 samples, two nearly identical headspace methods must be linked (the only difference between the two methods is the number of samples, which is discussed on the next page). Therefore, to create two identical headspace methods, let us set methods 1 and 2, the following methods are set in the usual way and are not affected by the constant heating time mode, select those parameters and initialize the headspace analysis.
. Headspace sample injection sequence (pressurization, emptying, injection)
. Headspace carrier gas flow
. Headspace auxiliary pressure
. Gas phase analysis conditions
- Carrier gas flow
- Column temperature program
- data processing
3 The REMOTE button on the controller can be controlled (red light), starting with the REMOTE button, and the headspace sampler will automatically start the next run, with or without the READY signal from the GC. After the start of REMOTE, the headspace control can be used to create an interval with the "SAMPLING INTERVAL" button.
- The injection interval can be extended by adjusting the equilibration time on the GC.
4 Alternatively, you can enter the desired value by the [SAMPLING INTERVAL" key to end the injection interval. This value must be greater than the analysis cycle time of the entire GC, and the REMOTE button must be turned off (red light off).
5 The following headspace parameters are used for option 1 when the maximum number of runs is 16.- Equilibration Time
Balance time (methods 1 and 2): 0 minutes
- Last Vial Number
Number of final vials (method 1): 23
- Last Vial Number
Number of final vials (method 2): 2
- Method Sequence
Method sequence : 1,2
6 Injection position / bottle number is entered as follows
- Method 1: Position 1, 2, 4, 5, 7, 8, 10, 11, 13, 14, 16, 17, 19, 20, 22, 23 Injection 1 time
Other locations 0 injections
- Method 2: Position 1-2 Injection 1 time
7 When the analysis begins, the first 3 positions in the headspace sampler should be empty.
8 Bottles 1-16 of the Headspace Sampler are loaded into the CHT as shown in Figure 3-7. Two or three weighted bottles should be placed at the end to allow all bottles to move.
9 Rotate the sample tray to position 1 and display it on the LED display. Use the [START / PAUSE" button on the headspace controller to start the analysis.
10 The headspace sampler begins the injection of position 1. Since there is no sample at position 1, a peak-free spectrum is produced. At the time of injection, the * actual sample is the sample that the autosampler adds to position 4 and heats.
11 When you turn to position 2, the vial is automatically added to position 5. When position 2 is injected, position 4 has been heated twice for analysis time and position 5 is heated once.
12 When the pan is turned to position 4 (skip position 4, because the number of injections at this position is set to 0), the vial enters position 7. The analysis at this time produced * peaks with a peak. After this run, the bottle at position 5 has been heated for 2 injections and position 7 has been heated once.
The 13 tray continues to advance, the vial enters position 8, and the sample at position 5 begins to analyze. At the end of the run, the sample is heated 2 times in position 7 and position 8 is heated once.
14 Continue running until all samples are heated 2 times, starting at time 1-2, and being added to samples 22-23. For example, when a No. 22 vial is added, the pan is turned to position 1.
15 When all samples have been analyzed according to Method 1, Method 2 begins with the original parameters of the sample at position 1-2 (relative samples are Nos. 15, 16). (Method 1 and Method 2 differ in that there is a one-minute delay to allow samples 15-16 to heat up for 1 more minutes than other bottles. Naturally, it has no major effect on the analysis, but the extra 1 minute will cause changes in the area of ??some peaks. Therefore, when analyzing by a single method, the number of samples should be limited to 14), and when the last 2 samples are completed, all 24 samples are analyzed.
Option 3 Each sample is heated at least once for analysis time.
The following parameters are used for this item:
2 Each sample is heated at least once for analysis time. For example, if Analysis + Report + GC Stabilization Time is 20 minutes, then each sample is heated for a minimum of 20 minutes.
3 Sample equilibration time may be longer than 1 analysis time. For example, if the sample analysis time is 5 minutes, the sample may be heated for 45 minutes longer than 5 minutes.
4 Three different injection parameters can be used. For example, different oil bath temperatures can be selected for different samples. The following example is to set the same parameters for all samples.
Procedure 3 Samples are heated at least once for analysis time
2 In order to run 16 samples, three nearly identical headspace methods must be linked (the only difference between the three methods is the number of samples, which is discussed on the next page). Therefore, to establish three identical headspace methods, let us set methods 1, 2 and 3. The following methods are set in the normal way and are not affected by the constant heating time mode. Select those parameters and initialize the headspace analysis. .
. Headspace sample injection sequence (pressurization, emptying, injection)
. Headspace carrier gas flow
. Headspace auxiliary pressure
. Gas phase analysis conditions
- Carrier gas flow
- Column temperature program
- data processing
3 The REMOTE button on the controller can be controlled (red light), starting with the REMOTE button, and the headspace sampler will automatically start the next run, with or without the READY signal from the GC. After the start of REMOTE, the headspace control can be used to create an interval with the "SAMPLING INTERVAL" button.
- The sample interval injection is equivalent to the sample cycle injection (ie, the gas phase emancipated balance signal after one injection)
- The injection interval can be extended by adjusting the equilibration time on the GC.
4 Alternatively, you can enter the desired value by the [SAMPLING INTERVAL" key to end the injection interval. This value must be greater than the analysis cycle time of the entire GC, and the REMOTE button must be turned off (red light off).
5 The following headspace parameters are used for option 1 when the maximum number of runs is 16.
- Equilibration Time
Balance time (methods 1 and 2): 0 minutes
- Last Vial Number
Number of final vials (method 1): 22
- Last Vial Number
Number of final vials (method 2): 23
- Last Vial Number
Number of final vials (Method 2): 24
- Method Sequence
Method sequence : 1,2,3
6 Injection position / bottle number is entered as follows
- Method 1: Position 1, 4, 7, 10, 13, 16, 19, 22 Injection 1 time
Other locations 0 injections
- Method 2: Position 2, 5, 8, 11, 14, 17, 20, 23 Injection 1 time
Other locations 0 injections
- Method 3: Position 3, 6, 9, 12, 15, 18, 21, 24 Injection 1 time
Other locations 0 injections
7 Two blank vials need to be prepared to be added to the vial row, that is, empty bottles of half a bottle of water are used, they do not need to participate in the injection.
8 When the analysis begins, the first 3 positions in the headspace sampler should be.
The above content is about The headspace sampler runs three basic programs I hope it will help you!
