Location:

Peak Table tab page
Report Variable (Peak Table)

Type:

Positive floating point number or string

Dimension:

Minutes or %

Value Range:

0.000 ... 999.999 or 0 - 100%

Absolute/Relative and
First/Greatest/Nearest/Spectrum/Spectrum and time

Default:

Autogenerate Peak Table: A third of the distance to the preceding or the succeeding peak depending on which distance is smaller

Else: 0.100 min or %

Absolute Greatest

Can be combined with:

Check the best hits only (with the peak match options Spectrum and Spectrum and Time only)

Related Parameters:

Retention Time

Description:

The Window parameter defines a tolerance interval within which the peak is expected. The start and end times of the retention window result from adding the window value to and subtracting it from the retention time (retention time +/- window value); that is, the window width is always twice as wide as your input. A peak outside this window is not identified. The window value defined here is either interpreted as absolute (minutes) or relative (percentage) value by the integration programs. For each peak, the interpretation can be individually specified, by adding a suffix to the window time.

Function:

The unit W of the time windows is calculated according to the following formula:

Absolute time window: W = TW

Relative time window: W = T x TW / 100

Where T is the retention time of the table and TW the entered window value. All peaks whose maximum falls into the time interval T+W belong to the time window.

Function of the suffixes:

• Select Absolute or add a capital A to the window value to indicate the window width in minutes.

• Select Relative or add a capital R to the window value to indicate the window width relative to the retention time.

If a peak is registered within this window, it is assigned the peak name entered in the peak table. If several peaks are located in the same window, the window parameter can be extended to determine which peak is identified:

• Select First to identify the first peak within the window (F).

• Select Greatest to identify the largest peak within the window (G).

• Select Nearest to identify the peak nearest to the specified retention time (N).

• Select Spectrum to identify a peak by a spectrum. The reference spectrum is specified in the Spectrum column of the peak table (S).

• Select Spectrum and time to identify a peak within a specific window width by a spectrum. The reference spectrum is specified in the Reference Spectrum column of the peak table (ST).

Via the Check the best hits only option, Spectrum and Spectrum and time allow you to check the hits with the largest Match Factors for the respective peaks only (= check box selected, default). The abbreviation for this is B (SB or STB).

If you have MS options installed, you can also enable the Check mass ratios option to check whether the masses indicated on the Mass Tracking tab page are found in the defined ratio range.

Examples:

Window Values: 0.2 AF / 0.2 AG / = 0.2 AN

If the expected retention time of the peak is Ret.Time = 5.0min and the window value is 0.2 A, the time window is 5.0min +/- 0.2min = 4min 48sec to 5min 12sec. By adding the suffix F, the first peak in the time window, by adding the suffix G, the greatest peak in the window, and by adding the suffix N, the peak nearest to the expected retention time is assigned.

Window Values: 10 RF / 10 RG

If the expected retention time of the peak is Ret.Time = 5.0min and the window value is 10 R, the time window has the range 5.0 min ± 10% = 5 min ± 0.5 min = 4 min 30 s to 5min 30 s. By adding the suffix F, the first peak in the time window, by adding the suffix G, the largest peak in the window is assigned.

 Note:

The absolute time interval of the window is twice as wide as the window value entered, since the interval reaches from T-W to T+W!