Hey everyone, I'm working on kind of an automated CE setup to serve as an aquarium sensor... The goal is to be able to separate as many dissolved ions (both positively and negatively charged) as possible, namely the ones which serve as the crucial building blocks of aquatic ecosystems (ammonia, nitrate, nitrite, chlorine, chloramine, salicylic acid, chelated metals, dissolved metals, phosphate, carbonic acid, possibly various heavier allelopathic agents. I've been mining through university papers on microfluidics setups for a few months now, trying to get an idea for the best way to do what I wanna do and I think I've found the answer. PLEASE correct me if I'm wrong???

I want to get a 4.5cm capillary engraved on a PMMA chip in the shape of a large radius parametric spiral, which spirals inward from one side then turns and spirals outward, exiting the other side. I am going to use hydrostatic injection provided by a few DIY syringe pumps loaded with very low-volume syringes. For detection I have decided to use Rhodamine B excited at 532nm at eight detection windows centered on the y-axis (the one without the sample and waste wells on the outside). To suppress the EOF I have decided to add PVP to the buffer, which I figure should be ADA to keep it at the pH required to suppress EOF in PMMA channels using PVP.


In the first stage, the channel gets flushed with deionized water and a cleaning solution in the central injection port. Once the cleaning cycle is finished the run buffer pvp and dye mixture gets introduced in the same port. The waste exits the ports on the sides which are extensions of, not perpendicular to the spiral channel. Once the channel is uniformly filled, confirmed by comparing the baseline fluorescence readings of each window, the sample is injected simultaneously into the two spiral "arms" and a high voltage is applied (I'm getting a power supply which provides up to 12kv). The separation is read through each of the eight windows and the results are compared and optimized in programming. After separating a few samples the cycle resets itself and the cleaning cycle happens again.

Do you guys see any problems with this setup provided the channel is uniform and has a sufficient turn radius and applied voltage to overcome the racetrack effect? Is the chemical setup correct? I fear the bullshit laws governing our universe are out to get me.