6 types of essential lab items when working with OMNISEC
People are cheering. The atmosphere is electric. You can’t walk down the hall without high-fiving someone. When your new OMNISEC system arrives it’s easy to get caught up in the excitement. And you should! But don’t let your eagerness distract you from being prepared to begin using your OMNISEC system.
While an OMNISEC system arrives with a starter pack of instrument-related consumables to get you going, there are several lab items that are useful to have on hand. In this post, I’ll go through the main ones and explain why they’re needed so you can hit the ground running with your new system!
Safety
Safety first! General lab PPE such as safety goggles, gloves, and a lab coat are usually sufficient for working with the samples and solutions involved with OMNISEC. However, some chemicals and samples may require extra protection. Please ensure you are aware of the specifications of each substance, or have access to its SDS, prior to handling.
Chemicals & solvents
When your OMNISEC system is installed, the engineer will use either THF or an aqueous mobile phase (0.05 M Na2SO4, PBS, etc.) to test the system. The mobile phase for your application will dictate which is required. THF will be used for organic systems; most aqueous solutions will work to test the instrument.
Methanol will be required to have at the lab to produce a back seal wash solution. This 90/10 water/methanol combination will be slowly pumped through the back side of the pump seals to minimize salt accumulation and prolong the lifetime and performance of the pump components.
Waste bottles
Two waste bottles are required for OMNISEC: one on top for the main mobile phase waste and the other as a drain bottle for autosampler wash waste, condensation collection, and leak protection. If you’re able, I recommend using a waste bottle made of chemically resistant plastic (less likely to break), translucent so you can monitor the waste level easily, and equal to or larger in volume than your mobile phase reservoir (to prevent overflow). Secondary containment units are ideal from a health and safety perspective, but I like to make sure they don’t inhibit visibility.
Tools
Tools are generally useful lab items to have, but there are some that are particularly helpful with OMNISEC. An adjustable wrench (or spanner for our British friends) with a range up to one inch (about 25 mm), along with 1/4 and 5/16 inch wrenches (or adjustable wrenches with a range that includes 5-10 mm) will allow you to work with most tubing connections. An additional one inch adjustable wrench is useful for changing the post-column filter, as detailed in the video in the linked post. A set of metric hex keys, specifically 2.5 and 3.0 mm, will prove useful when performing pump maintenance.
Mobile phase preparation
A vacuum filtration setup that includes a filter flask with a volume > 2 L is especially useful when working with mobile phases other than HPLC-grade solvents (e.g. THF, DCM, etc.). Anytime a salt or non-HPLC-grade additive is used, the resulting mobile phase should be filtered through a filter membrane with 0.2 µm pores. Nylon membranes work well for aqueous and most organic solutions; PTFE membranes work well for HFIP, formic acid, and other solvents that will dissolve Nylon. A stir plate and stir bar are useful for agitating the filtrate, further degassing it, as well as keeping mobile phases homogenous while in use.
You can see the mobile phase preparation lab items in action in the video below.
Sample preparation
The lab items you’ll need for sample preparation will vary depending on what materials you’re working with. I’ll describe what I use that tends to work well for almost all samples. Adjust your list according to your samples.
I prepare my samples in 20 mL vials. I generally make 5 or 10 mL of sample solution, depending on the sample availability, solvent in use, and desired concentration. I recommend using vials with PTFE-lined caps to avoid unintentional interactions with your sample solutions.
To filter my sample solutions, I use disposable Luer Lock syringes (without the black rubber stopper on the plunger!) and 30 mm diameter syringe filters with 0.2 µm pores. Nylon filters work well for aqueous samples, PTFE filters for organic samples, and cellulose acetate filters can be used for protein samples. I filter my sample solutions directly into autosampler vials. A pack of 100 autosampler vials comes with OMNISEC and additional packs in different varieties can be ordered from our eStore.
You’re almost certain to have these last two lab items readily available: a balance with sensitivity to at least 0.001 g and method of accurately dispensing 5 or 10 mL of solvent. These tools are helpful in preparing sample solutions of known concentrations. This is especially important if you don’t have an established dn/dc value for your sample!
My process for preparing a sample is demonstrated in the video below.
Final thoughts
In conclusion, I hope this list of essential lab items proves useful as you work with your OMNISEC. I’ve compiled a one-page summary of lab items here in case you want to print it out. Furthermore, if you have any questions, please don’t hesitate to contact us or email me directly at kyle.williams@malvernpanalytical.com.
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