Subscriber access provided by KUNGL TEKNISKA HOGSKOLAN
Article
Hand-portable Gradient Capillary Liquid Chromatography Pumping System Sonika Sharma, Alex Plistil, Hal E Barnett, H. Dennis Tolley, Paul B Farnsworth, Stanley D Stearns, and Milton L. Lee Anal. Chem., Just Accepted Manuscript • DOI: 10.1021/acs.analchem.5b02583 • Publication Date (Web): 17 Sep 2015 Downloaded from http://pubs.acs.org on September 19, 2015
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
Analytical Chemistry is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 18
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Analytical Chemistry
1
Hand-portable Gradient Capillary Liquid Chromatography Pumping System
2
Sonika Sharma†, Alex Plistil‡, Hal E. Barnett‡, H. Dennis Tolley‼, Paul B. Farnsworth†, Stanley
3
D. Stearns‡, Milton L. Lee†*
4
†
5
United States
6
Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602,
‡
VICI Valco Instruments, Houston, Texas 77055, United States
7
‼
Department of Statistics, Brigham Young University, Provo, Utah 84602, United States
8
*
Corresponding Author E-mail:
[email protected] 9
ABSTRACT: In this work, a novel splitless nano-flow gradient generator integrated with a stop-
10
flow injector was developed and evaluated using an on-column UV-absorption detector. The
11
gradient pumping system consisted of two nano-flow pumps controlled by micro stepper motors,
12
a mixer connected to a serpentine tube, and a high-pressure valve. The gradient system weighed
13
only 4 kg (9 lbs) and could generate up to 55 MPa (8000 psi) pressure. The system could operate
14
using a 24 V DC battery and required 1.2 A for operation. The total volume capacity of the pump
15
was 74 µL, and a sample volume of 60 nL could be injected. The system provided accurate
16
nanoflow rates as low as 10 nL/min without employing a splitter, making it ideal for capillary
17
column use. The gradient dwell volume was calculated to be 1.3 µL, which created a delay of
18
approximately 4 min with a typical flow rate of 350 nL/min. Gradient performance was
19
evaluated for gradient step accuracy, and excellent reproducibility was obtained in day-to-day
20
experiments (RSD < 1.2%, n = 4). Linear gradient reproducibility was tested by separating a
21
three-component pesticide mixture on a poly(ethylene glycol) diacrylate (PEGDA) monolithic
22
column. The retention time reproducibility was very good in run-to-run experiments (RSD
