Comparison of Different Techniques for the Determination of Platinized Cytostatic Drugs in Urine Samples

Abstract

Platinum-based cytostatic drugs are one of the most widely used cancer treatments. They are excreted via the urinary tract and can reach the environment through wastewater, posing a risk to human health due to their side effects. Four identification and quantification techniques, including liquid chromatography (LC) separation coupled to (i) a diode array ultraviolet (UV(DAD)) (ii), mass spectrometer in single ion monitoring mode (LC-MS) and (iii) multiple reaction monitoring mode (LC-MS/MS) and (iv) derivatization with diethyldithiocarbamate prior to LC-MS/MS analysis, have been optimized and compared for the multiresidue determination of main platinized cytostatic drugs (cisplatin, carboplatin, and oxaliplatin) in urine samples. Parameters that affect the efficiency of the chromatographic separation and analytical determination of different methods (column, mobile phase, wavelength, precursor ions, fragmentor, and product ions) were optimized. Analytical features, such as matrix effect, sensitivity, precision, selectivity, and linearity, were calculated. In terms of selectivity, the derivatization technique was discarded since it was only applicable to the platinated sum. A high dilution of the sample with LC-UV(DAD) was needed to reduce the matrix effect. Overall, the LC-MS/MS method presented the best analytical features (% RSD ≤ 12.8%, R2 ≥ 0.991, or method-detection limits between 0.01–1 µg mL−1). The selected method was applied to the quantification of platinized cytostatic drugs in hospital urine samples from oncologic patients.

Using HPLC for the determination of platinum drugs in biological matrixes after derivatization with diethyldithiocarbamate

“…Furthermore, no difference in sample pretreatment was described for plasma and urine [35], or it was even mentioned that both matrices were treated identically [37]. Even Arenas et al [33], who modified the previously published protocol [13], did not observe any problems related to matrix diversity when applying the derivatization MS/MS detection, only a higher matrix effect occurred with the method using UV detection without derivatization. Simple dilution of the samples with water (2-, 4-, and 10-fold dilutions were tested) did not give satisfactory results.…”

“…Because of all our unsuccessful experiments, we had some doubts about the suitability of DDTC derivatization for urine samples. In addition, as mentioned above, the previously published protocols [33,35,37] did not properly report the results for the determination in urine. Unfortunately, Gerina-Berzina et al [35] did not show the results of the sample treatment development and it was not specified for urine.…”

“…Shaik et al [37] presented validation data using plasma and urine as matrices, but the results of sample treatment and matrix behavior during this process were not reported. Arenas et al [33] tested different techniques for the determination of platinum drugs in urine, but observed the occurrence of a matrix effect only when other techniques were used. No similar problem was reported when using derivatization.…”

“…The reason for setting this transition was not explained, and we assume that it was due to the appearance of [M+NH4]+ ions in the spectrum. A similar approach of using [M+NH4]+ ions for detection was also used by Arenas et al [33] when problems with cisplatin fragmentation were observed. However, the above-mentioned approaches require expensive equipment or are not universally applicable for routine practice analyses.…”

“…A similar approach of using [M+NH4]+ ions for detection was also used by Arenas et al. [33] when problems with cisplatin fragmentation were observed. However, the above‐mentioned approaches require expensive equipment or are not universally applicable for routine practice analyses.…”