Raymond Wong

These are the consumables for the Nexera LC-40D pump. Replacement schedule is just an example and will vary depending on usage.     Inspection/ Maintenance Schedule Part No. Name 1 Ye...

Generic Reversed Phase Column Storage A proportion of organic is required to prevent microbial growth, however, 100% organic can cause leeching of metals from the steel column, which can have adve...

Generic Reversed Phase Column Clean An LC column is one of the most critical parameters in reversed phase chromatographic separation. The buffered mobile phases, corrosive additives and any strongl...

How is Dwell Volume Measured? Dwell volume (sometimes referred to as delay volume) is calculated from the point where two solvents first mix to the head of the column. This encompasses the tubing, ...

How is the Linearity of the Pump Measured? The linearity of the pump should be assessed between 0-100% using the conditions described in Figure 1. This is in order to ascertain the ability of the p...

When is Gradient Chromatography Used? The use of isocratic or gradient conditions are completely application driven, thus care should be given to select the most appropriate conditions. Some exampl...

What Does a Gradient Profile Look Like? The most frequently used gradient profile is the linear gradient. However, there are a variety of profiles which could be applied, including step, segmented...

Why is Gradient Chromatography Needed? Analytical samples are quite frequently made of complex analytes with varying physico-chemical properties, such as polarity. The analysis of these compounds u...

What is the gradient delay volume? The gradient delay volume is the volume between where the gradient is formed and the inlet of the column. This volume results in an unwanted isocratic hold at the...

Can Dispersion be Improved? There are a few options available in order to improve dispersion. However, it is important to discuss why the dispersion needs to be reduced. For example, it may not be ...