Ion chromatography as candidate reference method for the determination of chloride in human serum

Abstract

Background We developed an ion chromatography (IC) method for measurement of chloride in human serum which was regarded as a simple, rapid, accurate, and sensitive technique. The method will be hopefully selected as a candidate reference method. Method Serum aliquots of 0.1 mL were diluted 500 times with Milli‐Q water, and chloride in serum samples was measured by IC with a gradient elution procedure using a KOH eluent generator. Results Based on the data, chloride in human serum was well detected by IC. The calibration curve for chloride was linear in the concentration range from 0 to 0.42 mmol/L with a correlation coefficient of .99995 under the optimum experimental conditions. The chloride concentration had a good linear relationship with the peak areas of chloride. This method was sensitive because of the low limit of detection (LOD) and the low limit of quantification (LOQ) 9.87 × 10 −5 mmol/L and 3.27 × 10 −4 mmol/L, respectively. Besides, the method was highly precise with the within‐run coefficient of variations (CVs) for the measurement of low, medium, and high concentration level samples 0.32%, 0.73%, and 0.50%. As for the evaluation of accuracy, the biases were less than ±1% and 2% by comparing with National Institute of Science and Technology (NIST) standard material SRM 956d and 2013‐2018 IFCC‐RELA samples, respectively. Finally, the biases between IC method and the inductively coupled plasma mass spectrometry (ICP‐MS) method were less than 1% which showed good agreement. Conclusion Ion chromatography is a simple sample treatment procedure for the determination of chloride in human serum with high sensitivity and specificity. The proposed method could be recommended as a candidate reference method for the determination of serum chloride in human serum.

Acid–Base Imbalance in Pseudohypoaldosteronism Type 1 in Comparison With Type IV Renal Tubular Acidosis

“…In this study, normal chloride levels were defined as 98 to 106 mEq/L [ 20 ]. However, a precise definition of acidosis or acidemia is lacking; we found definitions of childhood metabolic acidosis as a pH < 7.35, HCO 3 − level < 22 mEq/L, or base excess ≤ 5 mmol/L [ 11 , 21 ].…”

Optimizing Available Tools for Achieving Result Standardization: Value Added by Joint Committee on Traceability in Laboratory Medicine (JCTLM)

“…LGC ERM-DA253a (frozen human serum) fulfil APS for the total MU budget on clinical samples regardless of the higher-order reference selected. To this regard, it would be interesting to determine whether the use of a RMP based on the ion chromatography principle may significantly improve the associated MU and permit the MU for chloride to get close to the APS as already observed for other plasma/serum ions (35,36).…”

Pseudohyperchloremia caused by the long-term use of phenobarbital and sodium bromide compound tablets: a case report

“…Using the peak area and the standard curve, the concentration of the target ion is calculated. Many studies have shown that IC accurately determines Cl − ions in serum and sweat samples (2,7), and it has been recommended as a candidate reference method for the determination of Cl − in human serum (2). In this case, we assumed that the 112 mmol/L Cl − concentration was more accurate than the 130 mmol/L concentration.…”

“…The Cl − level can be measured by numerous methods (2), such as the inductively coupled plasma mass spectrometry method, the ion chromatography (IC) method, the ion selective electrode (ISE) method, and the enzyme coupling method. IC is recommended as a candidate reference method because it is a simple, rapid, accurate, and sensitive technique (2). In relation to cost and convenience, the ISE method is the most common method used to determine the serum Cllevel in many hospitals.…”