Technical Support

If you have any technical question, please contact us at tech@nature-standard.com We will contact you as early as we could. Answers to some commonly asked questions are provided below.

Q1. Why is the concentration measured by me different from the value provided by NatureStandard?
A: Change of the wavelength and other test conditions affect the results. Please strictly follow the methods and conditions in the test report we provided to you, and verify that the energy level in HPLC is sufficient. If problem persists, contact us at tech@nature-standard.com or 86-21-51320077.

Q2. Why is there a tail in the HPLC peak?
A:This is a common phenomenon. In most circumstances, the tail reflects sample characteristics and column efficiency. Tails occur if the sample is glycosidic, acidic or alkaline. In most cases, this is not a serious problem that can be readily solved by adding small amount of volatile acid or alkali. If problem persists, remove the protective column and inject the sample again. If everything fails, contact us at tech@nature-standard.com or 86-21-51320077.

Q3. How to use signal-to-noise ratios (S/N) to evaluate my HPLC detector?
A: In order to define the sensitivity of a detector, it is necessary to define the minimum concentration that can be unambiguously identified when eluted from the column. A peak becomes obscured when its height approaches the noise level of the system. The source of the noise can arise from the chromatographic system, the sensor itself, or associated electronics. Typically, we use naphthalene and L-phenylalanine to test the signal and noise ratio at a wavelength of 254nm.

Q4. Why are there double peaks in HPLC?
A: In most cases, the problem resides in the column, such as inhomogeneity, contamination, and blocked sieve plates. Use a new column if necccesary.

Q5. Why does the peak area decrease when I repeat the test?
A: The most common reason is a leak in the pressure system of your HPLC. The second reason is sensitivity to light or heat. The third reason is low energy of HPLC detector.