Normally for 1H, it doesn't matter so much to tune the probe with or without a sample inside. And during the measurement, when I change the sample, tuning (usually) doesn't change much. But for 19F: I have two samples, let's call them A and B. Tuning the probe without any sample in. Then I put sample A, and wobb => the minimum moves 0.86MHz to the right of the tune-line. Then I put sample B, and wobb => it moves 2.2MHz to the left of the tune-line. A and B are rather complex molecules/solvents I am using the Bruker Topspin 300MHz. Am I doing something wrong? If not, what is the explanation?

Normally for 1H, it doesn't matter so much to tune the probe with or without a sample inside. And during the measurement, when I change the sample, tuning (usually) doesn't change much. But for 19F: I have two samples, let's call them A and B. Tuning the probe without any sample in. Then I put sample A, and wobb => the minimum moves 0.86MHz to the right of the tune-line. Then I put sample B, and wobb => it moves 2.2MHz to the left of the tune-line. A and B are rather complex molecules/solvents I am using the Bruker Topspin 300MHz. Am I doing something wrong? If not, what is the explanation?

Normally for 1H, it doesn't matter so much to tune the probe with or without a sample inside. And during the measurement, when I change the sample, tuning (usually) doesn't change much. But for 19F: I have two samples, let's call them A and B. Tuning the probe without any sample in. Then I put sample A, and wobb => the minimum moves 0.86MHz to the right of the tune-line. Then I put sample B, and wobb => it moves 2.2MHz to the left of the tune-line. A and B are rather complex molecules/solvents I am using the Bruker Topspin 300MHz. Am I doing something wrong? If not, what is the explanation?

Normally for 1H, it doesn't matter so much to tune the probe with or without a sample inside. And during the measurement, when I change the sample, tuning (usually) doesn't change much. But for 19F: I have two samples, let's call them A and B. Tuning the probe without any sample in. Then I put sample A, and wobb => the minimum moves 0.86MHz to the right of the tune-line. Then I put sample B, and wobb => it moves 2.2MHz to the left of the tune-line. A and B are rather complex molecules/solvents I am using the Bruker Topspin 300MHz. Am I doing something wrong? If not, what is the explanation?