Thermal degradation of polyethylene glycol 6000 and its effect on the assay of macroprolactin

Louise Boughen, John Liggat, Graham Ellis

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Study of the effectiveness of partially degraded polyethylene glycol 6000 (PEG) as a precipitant for macroprolactin. PEG was heated to 63 °C in air for up to 20 days and its effectiveness assessed as a precipitant for sera containing normal prolactin or macroprolactin. Decomposition was studied chemically and with NMR spectroscopy. Thermal degradation was similar to what had occurred over several years of natural degradation. Initially PEG degraded 2-5 days caused excess precipitation of monomeric prolactin (false-positive macroprolactinemia). Samples degraded 18-20 days failed to precipitate macroprolactin, giving false negative results. Two 1H NMR peaks at 4-4.5 ppm were not detectable in undegraded PEG but were after 1 day. Their relative integral increased to 20 days. Aging of PEG can be accelerated by heating. The suitability of PEG for use in macroprolactin assays can be assessed by the absence of peaks at 4-4.5 ppm by 1H NMR.
LanguageEnglish
Pages750-753
Number of pages3
JournalClinical Biochemistry
Volume43
Issue number9
DOIs
Publication statusPublished - 30 Jun 2010

Fingerprint

Assays
Pyrolysis
Hot Temperature
Nuclear magnetic resonance
Heating
Nuclear magnetic resonance spectroscopy
polymeric prolactin
Polyethylene Glycol 6000
Precipitates
Magnetic Resonance Spectroscopy
Aging of materials
Air
Decomposition
Degradation
Serum
Proton Magnetic Resonance Spectroscopy

Keywords

  • prolactin
  • polyethylene glycols
  • humans
  • reproducibility of results
  • magnetic resonance spectroscopy
  • temperature

Cite this

@article{ef444abdad774fa6ba5f57c34ece7fe5,
title = "Thermal degradation of polyethylene glycol 6000 and its effect on the assay of macroprolactin",
abstract = "Study of the effectiveness of partially degraded polyethylene glycol 6000 (PEG) as a precipitant for macroprolactin. PEG was heated to 63 °C in air for up to 20 days and its effectiveness assessed as a precipitant for sera containing normal prolactin or macroprolactin. Decomposition was studied chemically and with NMR spectroscopy. Thermal degradation was similar to what had occurred over several years of natural degradation. Initially PEG degraded 2-5 days caused excess precipitation of monomeric prolactin (false-positive macroprolactinemia). Samples degraded 18-20 days failed to precipitate macroprolactin, giving false negative results. Two 1H NMR peaks at 4-4.5 ppm were not detectable in undegraded PEG but were after 1 day. Their relative integral increased to 20 days. Aging of PEG can be accelerated by heating. The suitability of PEG for use in macroprolactin assays can be assessed by the absence of peaks at 4-4.5 ppm by 1H NMR.",
keywords = "prolactin, polyethylene glycols, humans, reproducibility of results, magnetic resonance spectroscopy, temperature",
author = "Louise Boughen and John Liggat and Graham Ellis",
year = "2010",
month = "6",
day = "30",
doi = "10.1016/j.clinbiochem.2010.02.012",
language = "English",
volume = "43",
pages = "750--753",
journal = "Clinical Biochemistry",
issn = "0009-9120",
number = "9",

}

Thermal degradation of polyethylene glycol 6000 and its effect on the assay of macroprolactin. / Boughen, Louise; Liggat, John; Ellis, Graham.

In: Clinical Biochemistry, Vol. 43, No. 9, 30.06.2010, p. 750-753.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Thermal degradation of polyethylene glycol 6000 and its effect on the assay of macroprolactin

AU - Boughen, Louise

AU - Liggat, John

AU - Ellis, Graham

PY - 2010/6/30

Y1 - 2010/6/30

N2 - Study of the effectiveness of partially degraded polyethylene glycol 6000 (PEG) as a precipitant for macroprolactin. PEG was heated to 63 °C in air for up to 20 days and its effectiveness assessed as a precipitant for sera containing normal prolactin or macroprolactin. Decomposition was studied chemically and with NMR spectroscopy. Thermal degradation was similar to what had occurred over several years of natural degradation. Initially PEG degraded 2-5 days caused excess precipitation of monomeric prolactin (false-positive macroprolactinemia). Samples degraded 18-20 days failed to precipitate macroprolactin, giving false negative results. Two 1H NMR peaks at 4-4.5 ppm were not detectable in undegraded PEG but were after 1 day. Their relative integral increased to 20 days. Aging of PEG can be accelerated by heating. The suitability of PEG for use in macroprolactin assays can be assessed by the absence of peaks at 4-4.5 ppm by 1H NMR.

AB - Study of the effectiveness of partially degraded polyethylene glycol 6000 (PEG) as a precipitant for macroprolactin. PEG was heated to 63 °C in air for up to 20 days and its effectiveness assessed as a precipitant for sera containing normal prolactin or macroprolactin. Decomposition was studied chemically and with NMR spectroscopy. Thermal degradation was similar to what had occurred over several years of natural degradation. Initially PEG degraded 2-5 days caused excess precipitation of monomeric prolactin (false-positive macroprolactinemia). Samples degraded 18-20 days failed to precipitate macroprolactin, giving false negative results. Two 1H NMR peaks at 4-4.5 ppm were not detectable in undegraded PEG but were after 1 day. Their relative integral increased to 20 days. Aging of PEG can be accelerated by heating. The suitability of PEG for use in macroprolactin assays can be assessed by the absence of peaks at 4-4.5 ppm by 1H NMR.

KW - prolactin

KW - polyethylene glycols

KW - humans

KW - reproducibility of results

KW - magnetic resonance spectroscopy

KW - temperature

UR - http://www.scopus.com/inward/record.url?scp=77952956286&partnerID=8YFLogxK

UR - http://www.sciencedirect.com/science/journal/00099120

U2 - 10.1016/j.clinbiochem.2010.02.012

DO - 10.1016/j.clinbiochem.2010.02.012

M3 - Article

VL - 43

SP - 750

EP - 753

JO - Clinical Biochemistry

T2 - Clinical Biochemistry

JF - Clinical Biochemistry

SN - 0009-9120

IS - 9

ER -