Evaporative analyzer as a mass detector for liquid chromatography

Charlesworth, John M.

doi:10.1021/ac50033a011

Cited by 279 publications

(118 citation statements)

References 28 publications

Supporting

Mentioning

112

Contrasting

Unclassified

Order By: Relevance

“…The response fits a power trendline (y ¼ ax b ) for the concentration response of the RI versus the voltage response of the ELS, which is similar to previous results. [3] The log a coefficient value for this particular plot was 5.489, the b coefficient value was 1.377, and the R 2 value was 0.9996. In addition, this plot contains the voltage response for the high molecular weight data points as well as the low molecular weight data points, and both sets fit the same power function.…”

Section: Calibration Of An Els Using Concentration Values From An Rimentioning

confidence: 76%

“…This is consistent with previous findings that indicate for compounds with similar refractive indexes and densities, the expected response from the ELS is the same for both assuming there are no chromophores in one of the compounds, which could absorb the light scattering signal. [3] All runs were then averaged to obtain a combined value. The combined average log a coefficient was ( The combined average a coefficient and the average b coefficient were used in the calculation of average MW for each of the three polysaccharides from the ELS voltage response and the data from the MALLS.…”

Section: Calibration Of An Els Using Concentration Values From An Rimentioning

confidence: 99%

“…For this reason, the RI works well under isocratic conditions, but is problematic to use when gradients are required. [3,4] For molecular weight determinations, a MALLS is less sensitive to gradients than RI, since salt or buffer gradients involve the use of small molecules (,1 kD) and small molecules scatter visible light waves to a much smaller extent than the large molecules typically being studied. Thus, a main limitation in doing molecular weight determinations under non-isocratic conditions with MALLS, is due to the difficulty in using the RI under these conditions as the mass detector.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Use of an Evaporative Light Scattering Detector Coupled to MALLS for Determination of Polysaccharide Molecular Weights

Luzio

2006

Journal of Liquid Chromatography & Related Technologies

View full text Add to dashboard Cite

A method to calibrate and use an evaporative light scattering detector (ELS) as a mass detector for molecular weight determination of polysaccharides using a multi-angle laser light scattering detector (MALLS) is described. The calibration of the ELS is performed under isocratic conditions using concentration values obtained from an interferometric refractive index detector (RI). The observed response fit a power trendline (y ¼ ax b ) for the concentration response of the RI versus the voltage response of the ELS. The combined average log a coefficient was (5.472, s.d. ¼ 0.020) and the average b coefficient was (1.372, s.d. ¼ 0.004) for all the runs. Band broadening, which could occur between the detectors, was not observed and did not affect the calibration values. Without adjustment the ELS was used as a mass detector for MALLS to accurately determine molecular weights (MW) at elevated buffer concentrations.

show abstract

Section: Calibration Of An Els Using Concentration Values From An Rimentioning

confidence: 76%

Section: Calibration Of An Els Using Concentration Values From An Rimentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Use of an Evaporative Light Scattering Detector Coupled to MALLS for Determination of Polysaccharide Molecular Weights

Luzio

2006

Journal of Liquid Chromatography & Related Technologies

View full text Add to dashboard Cite

show abstract

“…The determination of this additive is challenging because it does not have a strong chromophore, and therefore cannot easily be determined by UV photometric detection. Evaporative light scattering detection (ELSD) was explored as an alternative detector [5][6][7]. With ELSD, the analytes of interest are separated on a column and the effluent is passed through a nebulizer.…”

Section: Resultsmentioning

confidence: 99%

Analysis And Control Of Copper Plating Bath Additives And By-Products

Newton¹,

Kaiser²

2003

AIP Conference Proceedings

View full text Add to dashboard Cite

Abstract. New copper plating bath chemisties are being developed to meet the emerging need of plating copper into submicron features on semiconductor wafers. These chemistries are designed to provide a fast, efficient, fill for even the most challenging wafer terrain. It has been found that maintaining the concentration of the additives in these plating baths at certain levels is critical to the performance of the bath. Plating technology for semiconductor applications requires rigid bath control and disciplined methodology.Establishing correlations between what is found in the plated film and bath chemistry control parameters is fundamental in producing interconnects that are consistent and reliable. To establish these correlations, it is important to have a clear understanding of the chemical composition of the bath. It is theorized that the "suppressor" bath components help moderate the deposition rate of the copper fill and the "leveler" additives improve the topology of the copper overfill. Too much or too little of these components in the bath can be detrimental to the quality of the copper deposition and may result in "fill failure" leading to a higher than necessary scrap rate for the wafers. Indirect bath measurements, such as Cyclic Voltammetric Stripping (CVS), tell an incomplete story as these techniques only measures the combined effect of the additives and by-products on the plating quality. High Performance Liquid (HPLC) and Ion Chromatography are analytical techniques which provide important information on the concentration, chemical balance and trend measurement of major constituents such as additives, brighteners, boosters, stabilizers, carriers, levelers, inhibitors, accelerators, transition metals, metal complexes and contaminants in the plating bath. This information provides for improved device quality, reduced scrap rate and reduced costs of bath maintenance. This, however, is not the end of the story. In addition to additives, copper plating baths also contain process byproducts. This paper will cover the development of analytical methods using metal free liquid chromatography to quantify the components and any related by-products found in copper plating baths used for small-featured semiconductors..

show abstract

“…[13][14][15] In the 1970s, the evaporative light scattering detector (ELSD) was developed as a type of HPLC detector. [16][17][18][19][20][21][22][23] The evaporative light scattering detector is a universal detector and its response is a function of the mass of solute particles, regardless of their chemical identities. At present, light scattering techniques mainly operate in the visible region and a laser or high intensity light resource is usually used.…”

Section: Introductionmentioning

confidence: 99%

Deterniillation of Ammonium in Aqueous Samples by Gas Phase Light Scattering Using Hydrogen Chloride Gas as a Derivatizing Reagent Followed by Nondispersive Atomic Fluorescence Spectrometry

2017

View full text Add to dashboard Cite

A sensitive method was developed for the determination of ammonium in an aqueous solution based on gas phase light scattering. In a stream of carrier gas, the gaseous ammonia from the alkalized solution formed a volatile ammonium chloride derivative by reacting with gaseous hydrogen chloride; the gaseous ammonium chloride was analyzed by nondispersive atomic fluorescence spectrometry. The mechanisms of the method are elucidated based on evaporative light scattering detection. Parameters such as temperature, amount of sodium hydroxide, and carrier gas flow rate were studied. Under optimal conditions, the detection limit of ammonium-nitrogen was 0.045 μg. The method was successfully applied to the determination of ammonium in certified reference materials, and tap and seawater samples.

show abstract

Evaporative analyzer as a mass detector for liquid chromatography

Cited by 279 publications

References 28 publications

Use of an Evaporative Light Scattering Detector Coupled to MALLS for Determination of Polysaccharide Molecular Weights

Use of an Evaporative Light Scattering Detector Coupled to MALLS for Determination of Polysaccharide Molecular Weights

Analysis And Control Of Copper Plating Bath Additives And By-Products

Deterniillation of Ammonium in Aqueous Samples by Gas Phase Light Scattering Using Hydrogen Chloride Gas as a Derivatizing Reagent Followed by Nondispersive Atomic Fluorescence Spectrometry

Contact Info

Product

Resources

About