# Pipette Tip Ejection: Why It Matters

Ejecting a pipette tip sounds like the least interesting part of pipetting. You press a button, the tip falls off, and you move on. In practice, tip ejection is one of the highest-leverage moments in the entire pipetting technique. A correct ejection protects your sample from carryover, protects your pipette shaft from liquid contamination, protects the calibration of the instrument, and protects you from exposure to whatever you just aspirated. A sloppy ejection does the opposite on every count. The physical act takes less than two seconds per tip. Learning to do it reliably takes one short practice session at the bench, and the benefits compound over every plate, every PCR setup, and every extraction you run for the rest of your career.

This article covers the principle behind tip mounting and ejection, a complete step-by-step procedure, practical tips, the mistakes that show up most often in teaching labs, a troubleshooting table, and how ejection behavior connects to specialized tip-based workflows such as pipette tip solid-phase extraction and to pipette calibration.

## What Tip Ejection Achieves and When It Matters

Air-displacement pipettes, the standard handheld pipettes in [molecular biology](/blog/careers/molecular-biology), rely on a tight seal between the tip and the shaft nose cone. That seal is created when you press the tip onto the shaft, and it has to be broken cleanly when you discard the tip. Good ejection accomplishes four things at once.

First, it removes the tip without touching it. Many molecular biology workflows, including PCR setup, RNA work, and cell culture, are exquisitely sensitive to contamination. If you pull a used tip off by hand, you touch the outside of a tip that has contacted your sample, your reagents, or both. Your glove then becomes a contamination vector for everything else you touch.

Second, it protects the pipette shaft. When a tip is ejected cleanly, any residual liquid stays inside the tip and goes into the waste container with it. When a tip is wiggled off by hand or ejected over an open sample, residual liquid can smear on the shaft nose cone or flick into neighboring tubes. Liquid that enters the nose cone can wick past the piston seals and corrode or gum up the internal mechanism, which is one of the classic causes of drifting pipette calibration.

Third, it limits aerosol exposure. Ejecting a tip generates a small puff of air through the tip. If you eject above an open tube, or at eye level, that puff can aerosolize residual liquid. Aerosols are a recognized route of cross-contamination in nucleic acid work and a route of exposure when the liquid is hazardous.

Fourth, it keeps the workflow fast. A one-motion ejection into the correct waste receptacle takes less time than peeling a tip off with your other hand, and it avoids the mid-task glove changes that hand removal eventually forces on you.

You should apply a disciplined ejection technique every single time you pipette, but the stakes differ by context. Setting up reactions with template DNA, working with RNA, handling infectious material, dispensing toxic solvents, or running quantitation assays all raise the cost of a bad ejection from annoying to experiment-destroying or hazardous.

## The Principle: How Tip Mounting and Ejection Mechanisms Work

Modern pipettes use a nose cone (also called a shaft or tip holder) that grips the tip collar, a plunger that creates the air displacement for aspiration and dispensing, and a separate ejector mechanism driven by the thumb lever or button. The ejector typically includes a sliding collar or ejector rod that travels further than the plunger can and physically pushes the tip collar off the nose cone taper. Patents and engineering descriptions of pipette tip loading and ejection mechanisms describe exactly this arrangement, in which a dedicated ejector element overcomes the friction fit between the tip collar and the cone so that the user never needs to touch the tip itself [1]. Related designs describe the mating of the tip to the mounting cone and the synchronized movement of the ejector as one integrated system, which is why a tip designed for one pipette family may seat or eject poorly on another [2].

The seal depends on geometry. The nose cone is a polished, slightly tapered cylinder. The inside of the tip collar matches that taper. When you press the tip on with firm, even pressure, the plastic deforms slightly and grips. The ejector collar pushes on the wider rim of the tip collar, applying force in a straight line along the pipette axis, which pops the elastic grip loose. This is why the correct ejection motion is a straight push, not a twist or a pull.

Two practical consequences follow from this design. First, tip-to-pipette compatibility matters. Off-brand or deformed tip collars can eject unpredictably or seal poorly, and both problems trace back to that taper fit. Second, the ejector only works if you mounted the tip correctly in the first place. A tip pressed on at an angle sits crooked on the cone, seals unevenly, dispenses inaccurately, and often ejects partway or not at all.

## Materials and Equipment

| Item | Specification or working condition | Notes |
|--|--|--|
| Air-displacement pipette | Single-channel or multichannel, volume appropriate to task (for example, a 20 µL, 200 µL, or 1000 µL model) | Confirm the ejector moves freely before starting |
| Pipette tips | Manufacturer-recommended tips for the pipette model, sterile or filtered as required | Filtered (barrier) tips for aerosol-sensitive work |
| Tip waste container | Autoclavable tip discard tray, or a rigid sharps-style container for hazardous liquids | Keep it at bench height, within arm's reach |
| Biohazard or chemical waste stream | Labeled container matching the material handled | Follow your institution's waste policy |
| 70% ethanol (v/v in water) | Surface decontamination for bench and pipette | Standard laboratory practice |
| 10% bleach solution (1:10 dilution of household bleach) | Decontamination of surfaces exposed to biological material | Rinse with water or 70% ethanol after bleach contact with metal parts |
| Gloves | Nitrile or latex, task appropriate | Change immediately after any hand-to-tip contact |

## Pipette Tip Ejection Technique Step by Step

![Flow of a clean tip ejection, from the end of the dispense to checking the shaft and pressing on a fresh tip.](/article-images/illustrations/pipette-tip-ejection-technique-ejection-steps.webp)

The following procedure assumes a single-channel air-displacement pipette with a thumb- or plunger-activated ejector. Multichannel pipettes follow the same logic with a bar-style ejector.

1. **Finish the dispense completely before ejecting.** Press the plunger to the first stop to dispense, then press to the second stop (blow-out) if your technique calls for it, and only then lift the tip out of the liquid. **Reason:** ejecting while liquid remains in the tip wastes volume and sprays residue, and lifting the tip out mid-blow-out leaves a hang of liquid that will drip.

2. **Wipe the tip exterior only if the protocol requires it, never the orifice.** If you touched the tip to the inside wall of a tube or the liquid surface, some protocols call for touching the tip to the inside wall to remove external droplets before the final dispense. **Reason:** external droplets become the material that flicks or smears during ejection.

3. **Move the loaded tip over the correct waste receptacle.** For benign, nonhazardous tips, this is your tip discard tray. For tips that contacted infectious material, toxic chemicals, radioactive tracers, or ethidium bromide-type stains, this is the matching labeled waste container. **Reason:** the ejected tip carries whatever the sample carried, so the destination is decided before the ejection, not after.

4. **Position the tip below the rim of the waste container and roughly vertical.** Hold the pipette in your normal grip with the shaft pointing down into the container opening. **Reason:** a vertical orientation means gravity pulls the tip straight down and any residual liquid drains into the tip rather than onto the shaft, and being inside the container means the tip and any flicked droplets land in the waste.

5. **Press the ejector with a single firm stroke.** Depress the ejector button or lever fully in one smooth motion. The ejector collar slides down and pushes the tip collar off the cone taper. **Reason:** a full, single stroke overcomes the friction fit cleanly. Half-pressing leaves the tip partially seated, and repeated shallow presses work the collar back and forth and can crack the tip rim.

6. **Let the tip drop. Do not catch it.** **Reason:** touching the tip defeats the purpose of the ejector and contaminates your glove.

7. **Briefly confirm the tip is gone.** A glance at the shaft tells you whether the tip ejected fully or whether a cracked collar remnant is still seated. **Reason:** a collar fragment left on the cone compromises the seal of the next tip and can drive pipetting errors that look like calibration problems.

8. **If the tip did not eject, remove it by hand as a last resort, correctly.** Grip the tip by its upper collar, the part that never touched liquid, pull it straight off along the pipette axis, and discard it. Then change gloves if your glove contacted the tip body. **Reason:** pulling straight along the axis avoids levering the tip against the cone, which bends the ejector rod or damages the cone finish.

9. **Recoat the shaft between samples when needed.** If any liquid contacted the nose cone, clean it immediately with 70% ethanol on a lint-free wipe, and decontaminate according to your lab's SOP if the material was biological or hazardous. **Reason:** residual liquid on the cone wicks inward over time and is a leading cause of sticky plungers and volume drift.

10. **Re-seat a fresh tip with a quarter-turn press.** Push the new tip on with firm pressure and a slight twist (about a quarter turn) to ensure an even seal. **Reason:** a well-seated tip is the precondition for an accurate dispense and a clean ejection next time.

11. **Eject the final tip of a session before storing the pipette.** Never store a pipette with a tip mounted. **Reason:** a tip held on the cone for hours or days keeps constant spring pressure on the ejector and seals in any humidity or residue, both of which shorten the life of the seals and the cone finish.

12. **Hang the pipette on a stand or store it upright, volume set to its maximum or mid-range as your lab's policy directs.** **Reason:** upright storage keeps any internal condensation away from the piston, and the mechanical unload protects the internal springs.

Total hands-on time for a full eject-and-reseat cycle is two to three seconds. For a typical session of 100 pipetting events, disciplined ejection adds under a minute and saves far more time in avoided repeats.

## Pipette Tip Ejection Technique Tips

**Keep the waste container at the same height as your work.** Most bad ejections happen because the analyst stretches toward a container on the floor or across the bench. Bring the container to your elbows.

**Use filtered tips for aerosol-sensitive work.** A hydrophobic filter inside the tip blocks aerosols from reaching the pipette nose cone. This pairs with good ejection because the two controls act at different points: the filter protects the pipette during aspiration, and clean ejection protects the pipette at discard.

**Listen to the click.** On most pipette models, a clean ejection produces a crisp click as the collar releases. A muffled sound often means a cracked collar, a deformed tip, or a fouled cone. Treat the sound as a free quality check on every ejection.

**Match the ejector to the tip style.** Long universal tips, short tips, and extended-length tips shift where the collar sits relative to the ejector. If you switch tip brands or formats, do one practice ejection with water before you start real samples.

**Plan your geometry around the ejector, not just the plunger.** The thumb controls both the plunger and the ejector on most single-channel pipettes. When you are pipetting many samples, alternate hand position slightly between dispense and ejection so you are not fighting your own muscle memory at the moment of ejection.

**Discard tips between every sample in sensitive work.** This is standard practice for template DNA, RNA, and any assay where carryover changes the result. The ejection motion is your contamination boundary. Making it fast and reliable is what makes single-use tips affordable in time as well as in plastic.

**Degrease your thumb friction, not the cone.** Never put grease or silicone on the nose cone. If ejection feels sticky, the cause is usually residue inside the ejector collar or a worn O-ring, both of which are service items described in the manufacturer's maintenance documentation.

## Tip Ejection in Specialized Pipette-Tip Workflows

Tip ejection is not only about disposal. In a growing family of analytical methods, the pipette tip itself is the analytical device, and how you handle the tip at the end of the procedure determines whether your data survives.

In pipette tip micro-solid phase extraction (PT-μSPE), the tip is packed with an adsorbent so that analytes are captured as the sample is drawn through the tip repeatedly. This format has been demonstrated across an unusually wide range of chemistries. Graphene nanosheet-packed 100 µL tips connected to a syringe infusion pump extracted the antimicrobial triclosan from environmental water with a detection limit of 0.5 ng mL⁻¹ and recoveries between 94.6 and 102.4 percent [3]. A polyacrylate polymer grown on cotton fibers inside a pipette tip extracted the beta-blocker carvedilol from water and urine with recoveries of 92 to 106 percent and fabrication reproducibility within 3.0 percent within batch and 9.0 percent between batches. Cobalt metal-organic framework packed tips extracted levofloxacin from wastewater with a preconcentration factor of 200 and RSD below 2.75 percent [4]. Molecularly imprinted polymer tips, in which the sorbent is polymerized around a template molecule so that it selectively binds that one analyte, have been used for profenofos in seawater, rice, and fish with a detection limit of 0.33 µg/L and reproducibility better than 5.6 percent RSD [5], for levofloxacin across seawater, pills, urine, and plasma, and for methyl red in seawater with recoveries of 84.0 to 98.0 percent [6]. Adsorbent chemistries continue to expand, including polystyrene foam composites for lead extraction from water, juice, and iced tea with an extraction efficiency of 95 percent [7], covalent organic framework monoliths for six estrogens in soil with limits of detection of 0.5 to 1.0 ng g⁻¹ [8], MOF-derived nanostructures for three antihypertensive drugs in mouse plasma with preconcentration factors up to 38.2 [9], mesoporous polypyrrole tips for enalapril in urine where the adsorbent was reused three times [10], cotton-composite covalent organic frameworks for the algal toxin domoic acid in seafood at a detection limit of 5 pg mL⁻¹ [11], and in-situ polymerized monoliths for phenoxycarboxylic acid herbicide extraction performed directly at the sampling site [12]. Even sustainability enters the design, as with olive pit-derived carbon black used to extract caffeine from energy drinks with one milligram of sorbent and minimal solvent [13], and a commercially available Salivette material repurposed as a tip sorbent that reduced the number of aspirating and dispensing steps and thereby reduced analyst fatigue [14].

Every one of these workflows ends with the analyst manipulating a liquid-filled, sorbent-loaded pipette tip. The ejection step matters here in specific ways.

**Contamination direction reverses.** In ordinary pipetting, the tip carries traces of your sample into the waste. In PT-μSPE, the tip may carry a concentrated analyte load, at enrichment factors often above 30 [7][9], and any flick of that residue can contaminate the bench, the next sample, or the analyst's gloves with amounts that dwarf the levels being measured.

**Tips are sometimes reused, sometimes not.** Some protocols report reuse of the extracted tip, as in the polypyrrole enalapril method where the adsorbent was reused three times [10]. Others treat each tip as single use. Know your protocol before you eject, because an ejected and discarded sorbent tip is data you cannot recover.

**Ejection mechanics affect the packed bed.** Tips packed with particulate sorbents rely on the flow path through the bed. Hard impacts or ejection attempts that partially dislodge the packing can crack the bed, which shows up as variable back pressure and variable recovery on the next run. Notably, some sorbent formats were designed specifically to reduce high back pressure within the tip, which accelerates extraction and reduces the force the analyst applies through the plunger [11]. Gentler, controlled handling of packed tips protects that engineering.

**Sensor-integrated tips extend the principle.** Pipette tips are also becoming instruments in their own right. One reported design integrates a capacitive microsensor into a 3D-printed tip structure and successfully detects cell suction and ejection events for robotic cell manipulation [15]. In that context, ejection is a measurable physical event with engineering specifications, a useful reminder that the mechanical details of how a tip leaves the cone are real, quantifiable phenomena rather than bench folklore.

## Common Mistakes and Limitations

The mistakes below account for most of the problems instructors see in teaching labs and most of the quiet contamination events in research labs.

**Ejecting above an open sample or rack.** The ejected tip carries a puff of air and often a droplet. Ejecting over an open tube, an open reagent reservoir, or a rack of finished PCR tubes risks depositing that material where it can ruin the downstream experiment. Always eject inside the waste container, never over anything you care about.

**Pulling tips off by hand as a habit.** Hand removal transfers sample residue to the glove, bends the cone geometry over time, and accelerates wear on the nose cone surface that the seal depends on. Reserve hand removal for the rare stuck-tip situation described in the procedure above.

**Flicking the pipette to shake a tip loose.** A sharp wrist motion when a tip resists ejection can fling residual liquid several feet. If the tip does not eject with one firm press, stop, inspect, and remove it deliberately.

**Ignoring a cracked collar after ejection.** When the plastic collar shatters during ejection, fragments stay on the cone. The next tip seats over those fragments, seals unevenly, and dispenses a volume that depends on how the plastic happened to settle. This is one of the most common hidden causes of reproducibility problems that get misattributed to reagent issues.

**Ejecting with the plunger still depressed.** Some analysts hold the plunger at the second stop and press the ejector in the same motion. On many models this works, but holding the plunger down while ejecting means any spring-back of the plunger can draw air (and aerosols from the tip) back toward the nose cone. Finish the dispense, release, then eject.

**Storing the pipette with a tip mounted.** Beyond the ejector spring fatigue mentioned above, a mounted tip protects nothing and can hide a fouled cone from view during routine inspection.

**Treating the waste container as an afterthought.** A tip discard tray overflowing past its rim forces the next ejection to happen over contaminated plastic. Empty it before it fills.

**Confusing ejection problems with calibration problems.** A pipette that dispenses inconsistently after a tip jam may have a bent ejector rod or a fouled cone, not a calibration failure. Diagnose the mechanical cause before sending the instrument away, because a service visit that misses the real cause will not fix the pipetting.

**A limitation to keep in mind:** individual protocols and institutional biosafety or chemical hygiene plans set specific requirements for waste segregation, decontamination, and tip handling. Where this general procedure and your local SOP differ, follow your SOP, and for any hazardous-material question consult your safety officer.

## Troubleshooting Guide

![Decision path for a stuck pipette tip: try one firm press, check the cone for fragments, then pull straight off by the collar.](/article-images/illustrations/pipette-tip-ejection-technique-stuck-tip-triage.webp)

| Symptom | Likely cause | Fix |
|--|--|--|
| Tip does not eject on one press | Tip collar deformed, cone contaminated with residue, or ejector rod misaligned | Remove the tip by hand along the pipette axis, clean the cone with 70% ethanol, inspect the ejector movement with no tip mounted, and switch to a fresh tip from a different box position |
| Tip collar cracks or shatters during ejection | Excessive ejector force, mismatched tip, or brittle tip plastic (often after prolonged autoclaving or long storage) | Press the ejector with firm but controlled force, verify the tip is rated for the pipette model, and remove collar fragments from the cone before the next tip |
| Residual droplet flicks out during ejection | Ejecting with liquid still in the tip, or ejecting too energetically after blow-out | Complete dispense and blow-out before ejecting, orient the tip downward inside the waste container, and use one smooth stroke |
| Next tip seats loosely or wobbles | Collar fragments on the cone, or a scratched cone finish | Remove fragments with forceps, never scrape the cone with metal, and have the cone inspected or replaced if scratches are visible |
| Volume drift after a ejection-related jam | Liquid entered the nose cone and reached the piston seals | Disassemble per the manufacturer's maintenance guide, clean and dry the cone, replace seals if the manual directs, then verify performance against calibration targets |
| Ejector button sticky or slow | Residue inside the ejector collar track | Clean per the manufacturer's instructions, and keep lubricants off the cone itself |
| Carryover contamination in sensitive assays | Aerosol generated at ejection, or glove contact with used tips | Switch to filtered tips, eject below the container rim, and change gloves immediately after any hand-to-tip contact |
| Packed or sorbent-loaded tip cracks the bed during ejection | Excessive force on a fragile packed bed (relevant to PT-μSPE workflows) | Follow the protocol's specified handling for loaded tips, and discard rather than reuse any tip whose bed has visibly shifted |

## How Ejection Behavior Connects to Pipette Calibration

Pipette calibration is the periodic verification and adjustment of a pipette's dispensed volume against a traceable standard, most commonly done gravimetrically by weighing dispensed water and converting mass to volume with a temperature correction. A pipette's accuracy depends on a chain of components: the piston, the seals, the spring, the cone finish, and the seal between cone and tip. Tip ejection touches that chain at both ends.

At the front end, a clean ejection leaves the cone finish intact and dry, which preserves the friction fit that the next tip needs. At the back end, ejection is your last line of defense against liquid entering the nose cone, which is one of the most common causes of seal degradation and the slow volume drift that eventually shows up as a failed calibration check. In other words, disciplined ejection is cheap preventive maintenance that extends the interval between calibration failures.

Calibration itself verifies the instrument, but a calibration check performed with poorly mounted tips will fail even on a healthy pipette, because an angled or partially seated tip changes the dead air volume inside the tip and the friction at the cone. When you run or witness a gravimetric check, mount each calibration tip exactly as you would for real samples, and eject it exactly as you would at the bench. Consistency between how you calibrate and how you work is what makes the calibration certificate mean anything on an ordinary Tuesday.

If your pipette shows any of the following, schedule calibration or service: dispensed volumes drifting from the set value, a plunger that feels different over weeks, an ejector that requires more force than it used to, or visible liquid inside the nose cone. Daily quick checks with a balance, or volume verification with a calibrated pipette-checking instrument, catch drift early.

## Safety Notes

Two moments in the ejection workflow carry hazard exposure. The first is the puff of air at ejection, which can aerosolize residual liquid. Keep the tip pointed down and inside the waste container, keep your face away from the shaft, and use filtered tips when handling biohazardous or volatile material. The second is the discarded tip itself. A tip that contacted infectious agents, cytotoxic drugs, strong stains, or organic solvents is chemically or biologically contaminated waste, and it must go into the waste stream that matches the hazard, never into a general trash bin and never back into a clean tip box. When decontaminating the pipette after any spill or visible contamination, 10% bleach is effective for biological material, but bleach corrodes metal, so follow bleach contact with a water or 70% ethanol wipe on metal surfaces, and always consult your institutional chemical hygiene plan for chemical residues.

## Frequently Asked Questions

### Why does the pipette have a separate ejector button instead of using the plunger?

The ejector needs to travel further than the plunger can in order to push the tip collar off the cone, so pipettes use a dedicated collar or rod driven by its own stroke. Designs described in the engineering literature pair the mounting cone and the ejector as one integrated system so the user never needs to touch the tip [1][2]. Keeping the two functions separate also prevents plunger spring-back from drawing aerosols toward the piston at the moment of ejection.

### Can I reuse pipette tips to save money?

For most molecular biology work, no. A tip that touched your sample is contaminated from the moment it touched, and washing cannot reliably restore it to a defined state. In specialized analytical formats, some protocols deliberately allow a fixed number of reuses, such as the mesoporous polypyrrole tip that was reused three times in the enalapril method [10], but that reuse is part of a validated protocol, not a general bench rule. Follow your protocol, and default to single use for anything sensitivity-critical.

### My tip will not eject. Should I twist it off?

No. Twisting levers the tip against the cone and can bend the ejector rod or scratch the cone finish. Press the ejector once firmly, and if the tip stays, pull it straight off by the upper collar along the pipette axis, then clean and inspect the cone before mounting the next tip.

### Does tip ejection really affect my pipette calibration?

Indirectly, yes, and significantly. Calibration measures the piston and seal system, and liquid that enters the nose cone during sloppy dispensing or messy ejection degrades seals over time, which is a common cause of volume drift. Clean ejection keeps liquid out of the mechanism and preserves the cone finish that tip sealing depends on, so it extends the life of a calibration.

### How far should I hold the tip into the waste container when I eject?

Below the rim and pointing down, with enough clearance that the falling tip does not strike the container edge. You do not need to bury the pipette nose cone in the container, and you should never eject with the tip horizontal or above the rim, because both orientations let residue travel where it should not.

### What is the right container for used tips?

It depends entirely on what the tip contacted. Clean, nonhazardous tips go into a standard tip discard tray or autoclave bag per your lab's convention. Tips that contacted biohazardous material, toxic chemicals, stains, or radioactive tracers go into the corresponding labeled waste stream. Decide the destination before you lift the tip out of the sample, so the ejection motion carries the tip straight to the right place.

### Do multichannel pipettes eject differently?

The principle is identical, but multichannel pipettes use a sliding bar rather than a single button, and all tips must release together. If one tip in a row fails to eject, the usual causes are a deformed collar on that tip position or an angled mount. Check each cone individually, and do not force the bar repeatedly, because repeated hard strokes misalign the ejector mechanism.

### Are pipette tips ever more than disposable plastic?

Increasingly, yes. In pipette tip solid-phase extraction, the tip is the extraction cartridge, and the field has demonstrated this format with graphene nanosheets for triclosan [3], polyacrylate on cotton for carvedilol, cobalt metal-organic frameworks for levofloxacin [4], molecularly imprinted polymers for profenofos [5] and methyl red [6], and monolithic phases for herbicides captured during on-site field extraction [12]. Sensor-integrated tips can even detect cell suction and ejection events during robotic cell transfer [15]. In all of these, the mechanical handling of the tip, including how it is mounted, aspirated, and finally ejected, is part of the analytical method itself.

## Sources

1. [Pipette tip loading and ejection mechanism and associated pipette tip](https://www.semanticscholar.org/paper/22953ca3e8942b05fe131bb7282d4b88d1ce6cbe)
2. [Pipette tip mounting and ejection mechanisms and associated pipette tips](https://www.semanticscholar.org/paper/73f7de6a04fb662fc4ef73eea22c43c362897cb3)
3. [Novel semi-automated graphene nanosheets based pipette-tip assisted micro-solid phase extraction as eco-friendly technique for the rapid detection of emerging environmental pollutant in waters.](https://pubmed.ncbi.nlm.nih.gov/33690040/)
4. [Application of pipette-tip solid-phase extraction technique for fast determination of levofloxacin from wastewater sample using cobalt metal-organic framework](https://doi.org/10.24200/amecj.v5.i02.185)
5. [Determination of profenofos in seawater and foodstuff samples after its molecularly imprinted polymer pipette-tip micro solid phase extraction optimized by response surface methodology](https://pubmed.ncbi.nlm.nih.gov/35292077/)
6. [Application of Box-Behnken design in response surface methodology for the molecularly imprinted polymer pipette-tip solid phase extraction of methyl red from seawater samples and its determination by spectrophotometery.](https://pubmed.ncbi.nlm.nih.gov/30503439/)
7. [Polystyrene foam-based pipette-tip Micro-solid phase extraction (PFPT-μSPE) using Ni-MOF@S-CQDs nanocomposite: A novel method for efficient extraction of Lead from water and food samples.](https://pubmed.ncbi.nlm.nih.gov/40513487/)
8. [Preparation of cobalt porphyrin-based covalent organic framework doped poly(deep eutectic solvent-co-ethylene glycol dimethacrylate) monolithic column for pipette tip micro solid-phase extraction of estrogens.](https://pubmed.ncbi.nlm.nih.gov/41241482/)
9. [High-Efficient pipette tip micro-solid phase extraction based on thickness controllable MOF-derived Cu@N-doped carbon hexagonal nanostructures for simultaneous determination of anti-hypertensive drugs in mice plasma.](https://pubmed.ncbi.nlm.nih.gov/40659113/)
10. [A Self-Assembly Pipette Tip Restricted Access Mesoporous Polypyrrole Solid-Phase Extraction Coupled With Capillary Electrophoresis With Diode Array Detection for the Determination of Enalapril in Urine Samples](https://pubmed.ncbi.nlm.nih.gov/40047288/)
11. [Mechanochemical synthesis ionic covalent organic frameworks/cotton composites for pipette tip solid-phase extraction of domoic acid in seafood.](https://pubmed.ncbi.nlm.nih.gov/38048683/)
12. [On-site extraction of phenoxycarboxylic acid herbicides in environmental waters utilizing monolith-based in-tip microextraction technique.](https://pubmed.ncbi.nlm.nih.gov/39260149/)
13. [OLIVE PITS-BASED CARBON BLACK AGGLOMERATE AS AN ADSORBENT FOR PIPETTE-TIP SOLID-PHASE EXTRACTION FOR THE DETERMINATION OF CAFFEINE IN ENERGY DRINKS](https://doi.org/10.35812/cellulosechemtechnol.2024.58.57)
14. [Expanding the applicability of biocompatible Salivette® as extraction sorbent in pipette-tip format: Determination of memantine in human urine as proof-of-concept.](https://pubmed.ncbi.nlm.nih.gov/40882357/)
15. [A Pipette Tip Integrated with a Capacitive Microsensor Fabricated by Combined 3D Printing and MEMS Process for Cell Detection and Transportation](https://doi.org/10.1109/MEMS49605.2023.10052499)